Wikipedia talk:WikiProject Mathematics/Archive/2015

Jan 2015

Watchlist bug

Is it only me experiencing that this page does not always show up on the watchlist? YohanN7 (talk) 07:03, 25 December 2014 (UTC)

My guess would be that when Wikipedia is busy changes to a page take some time to be reflected on your watch-list. I doubt that updating watch-lists is the top priority of the system. JRSpriggs (talk) 12:29, 25 December 2014 (UTC)

Updating watch-lists is obviously one of the main priorities of the "system". It relates directly to user experience. I also didn't ask if my observation is important. I asked if anyone else has seen it. YohanN7 (talk) 11:31, 26 December 2014 (UTC)

I have not noticed it. But it is unlikely that I would since I rarely look at this page except as a result of it being on my watch-list.

The experience of the general user (who is not an editor) would probably be a higher priority than that of an editor. Only editors are likely to use watch-lists. JRSpriggs (talk) 14:39, 26 December 2014 (UTC)

Editors are likely to be online browsing, reading and editing 100 times more than mere readers per month Just to make clear what is annoying with this bug: I frequently have to type "Wikipedia talk:WikiProject Mathematics" in the search box. (I am a clumsy typist.) I know, I could create a link on my user page. YohanN7 (talk) 14:19, 28 December 2014 (UTC)

...or just type WT:MATH in the search box :) No such user (talk) 18:08, 28 December 2014 (UTC)

Short for WikiTroject MATHematics? Wouldn't work. Wouldn't remember it from one hour to the next. YohanN7 (talk) 18:17, 28 December 2014 (UTC)

And WT:WPM, documented at the top of this page, has one letter less, and is hopefully more intuitive ;). No such user (talk) 10:58, 29 December 2014 (UTC)

I have a lengthy list of links at the top of my talk page (most editors put this list on their user page). One of them is a link to this page. So I could just click on the "talk" link to get to my talk page and then click on my link to this page. Easy. JRSpriggs (talk) 00:44, 29 December 2014 (UTC)

YohanN7, when you look at your watchlist, do you see a link that says "Show bots"? If so, that's your problem. When your watchlist is set to "hide bots", then it hides any page whose last edit was performed by a bot—even if there were dozens of non-bot edits since the last time you looked at it. You can change your watchlist settings permanently at Special:Preferences#mw-prefsection-watchlist. If you're the sort of editor who checks Wikipedia all day, every day, even when you're on vacation, then I recommend setting your watchlist to show everything, even bot edits. Whatamidoing (WMF) (talk) 00:27, 2 January 2015 (UTC)

Thanks, but I have it set to "show bots". When the problem "happens" it is as if I don't have the page on the watchlist at all, even if it is listed in the watchlist, at least, when I go here after a few days suspecting that the watch feature has broken down, the watch-tab is still set to "on", and there may be several new posts on the page. I emphasize that this isn't a big problem, but I find it curious. It has been this way for some time, probably a year. It is browser-independent (IE/Chrome/Mozilla). It is exclusively this page that is affected. YohanN7 (talk) 00:40, 2 January 2015 (UTC)

List of matrix decompositions

Interpolative decomposition is a new article. Because it is an orphan, I thought maybe list of matrix decompositions should link to it. But that doesn't exist. Should it? Michael Hardy (talk) 22:45, 2 January 2015 (UTC)

Yes. -- Taku (talk) 00:39, 3 January 2015 (UTC)

There's an article, matrix factorization. YohanN7 (talk) 05:10, 3 January 2015 (UTC)

Quaternion rotation biradial

This is the one of the most extreme articles I have seen, It's too long to read, so I can't say anything except that I strongly doubt that it belongs in an encyclopedia. YohanN7 (talk) 18:33, 1 January 2015 (UTC)

The lead could be the lead of an article in Wikipedia, if a notable concept. The claim that Hamilton used it would not be sufficient for notability, even if verified. Perhaps it might fit in Wikibooks or Wikiversity. — Arthur Rubin (talk) 19:49, 1 January 2015 (UTC)

I agree with Arthur--the level of detail in the article is more appropriate for a monograph or textbook, so Wikibooks or Wikiversity seem reasonable destinations. Based on a quick GScholar search, the quaternion biradial is not a notable concept. The concept is perhaps worth a summary in Quaternions and spatial rotation. --Mark viking (talk) 23:53, 1 January 2015 (UTC)

This is a particularly egregious example of the walled garden of geometric algebra content on Wikipedia. It's been clear for awhile that this garden could do with some pruning, but someone really need to make it their mission to do that. And, also, collaborate with the GA people too—some of them are a little wacky. We do have some semi-active editors User:JohnBlackburne and User:Quondum who would probably be good at this, but who really has the time and patience for such a task? I, for one, am willing to leave these things be. Sławomir Biały (talk) 00:38, 2 January 2015 (UTC)

Woo-hoo! It's so long, it is a mission just to scroll through it. My guess is that it is a transcription of a thesis or some papers or textbooks (the comments on the talk page seem consistent with this); it seems too far-ranging and detailed to have been freshly created from multiple sources as an article. My reaction is that it could be simply deleted, as I agree that it does not belong in WP as an article. It has been written recently (since April 2014), in its entirety, by a single editor. I don't feel the impulse to do anything but point out to the editor that this sort of article is not what WP is about. —Quondum 04:33, 2 January 2015 (UTC)

Further to that it looks like one of the many things dreamed up in the 19th century which was superseded by geometric and/or matrix algebra when they were developed. It's worth a mention, as a stub-like article which acts as a brief reference for anyone looking for it, or within another article if one's found suitable. The rest just doesn't belong, at least not on WP.--JohnBlackburne^words_deeds 05:21, 3 January 2015 (UTC)

Yeah, it seems like this article should be deleted and/or stubified by someone who thinks they can do it justice. Rschwieb (talk) 17:12, 7 January 2015 (UTC)

---

I have copied the above to the articles talk page and notified the creator. YohanN7 (talk) 22:09, 7 January 2015 (UTC)

---

Hello, I wrote the page from my own research, not as a thesis draft or anything like that. I am okay if the page is deleted, or torn into more than one wiki page, or whatever. I just felt like trying to contribute some information that might be useful. If it could be moved into a wikibook, that would be fine. I don't know how to make a wikibook, so if anyone wants to just do that, that would be great. Actually, I have anticipated that this kind of negative discussion would occur, and that the article would come up for deletion. I've just been waiting. Before deleting, just consider for a moment that the article does contain some valuable information. The article is large and ugly, but I think it could be very useful to some students trying to learn something about those quaternions and how they work in geometric algebra. The approach taken by explaining quaternions as the product or quotient of vectors is not found in many books. The article went a bit too far maybe, but what I added I felt was very useful to just dump there. The section on the "expansion of the geometric product of blades", something fundamental really but a bit advanced, is strangely enough something you can hardly find in any book, and where it is mentioned, it is still not explained well enough to be usable. Try learning the subject some before just deleting it, and maybe see that the article has something to offer. The page appears to be viewed very little according to the page view statistics, so it is mostly just sitting there causing no real harm to wikipedia yet has potential to provide info to someone searching for it. Twy2008 (talk) 19:37, 9 February 2015 (UTC)

Eyes requested on Catalan number

There is a small-scale edit war at Catalan number and I would be grateful if another editor would take a look at the recent edits there. Thanks. (I will probably not be able to make any substantive edits in the next 2 weeks or so.) --JBL (talk) 03:04, 8 January 2015 (UTC)

Wikipedia talk:Articles for creation/François Fages

Hello mathematicians. I have added some sources to this old AfC submission, and moved changed the self-references to publications. Is this a notable mathematician, and should the page be moved to mainspace? —Anne Delong (talk) 04:14, 9 January 2015 (UTC)

Help

Here is quote I have been having a hard time understanding in my research:

"Figure 4 shows the cumulative volume of erupted material versus time for the northern Cordilleran volcanic province; the slope is a qualitative measure of the overall rate of magmatism (km³/m.y.). Although the rate of magmatism has varied substantially through time, there is no correlation between the rate of magma production and the number of active centers during any interval of time (Edwards and Russell, 1999). Initially (20 Ma) volcanism was sporadic, producing small volumes of material. The eruption rate increased markedly (e.g., ~10^–4 km³ yr^–1) when volcanism began at Level Mountain at 15 Ma. When Mount Edziza began to erupt (ca. 7 Ma), rates of magmatism for the northern Cordilleran volcanic province increased to ~3 × 10^–4 km³ yr^–1 (Fig. 4). Between ca. 4 and 3 Ma a magmatic lull appears to have ensued; subsequently rates of magmatism have remained relatively constant at 10^–4 km³ yr^–1. Current rates of magmatism for the northern Cordilleran volcanic province are much less than those estimated for Hawaii (10^–1–10^–3 km³ yr^–1; Shaw, 1987) or the Cascade volcanic arc (0.2–6 km³ yr^–1; Sherrod and Smith, 1990)."

Can someone explain to me what these numbers mean (e.g. ~10^–4 km³ yr^–1) in a more simple format? Volcanoguy 02:14, 10 January 2015 (UTC)

In this context, "~" means "about" (roughly, approximately). "10^–4" means one divided by ten four times, that is, ${\frac {1}{10\;000}}$. "km³" means cubic kilometres of magma, i.e. a billion (1 000 000 000) cubic metres (although usually not in the form of a cube, but spread out more horizontally). "yr^–1" means "per year" (probably averaged over some lengthy period of time). So this example translates to "about 100 000 cubic metres of magma per year". JRSpriggs (talk) 11:05, 10 January 2015 (UTC)

Yes, in more commonly used units, 10^–4 km³ yr^–1 means that the volcano(es?) is releasing 100 million liters (or 26.4 million gallons) of matter (magma?) per year. FireflySixtySeven (talk) 11:45, 10 January 2015 (UTC)

Incidentally, there is the Wikipedia:Reference desk/Mathematics, where questions of this sort will be answered quicker than here. It is usually also interesting to read other peoples questions and their answers over there. YohanN7 (talk) 19:34, 10 January 2015 (UTC)

Betti numbers and torsion coefficients

Hi,

I have started a discussion at Talk:Homology (mathematics)#Betti numbers and torsion coefficients on how to present these topological invariants. All contributions gratefully received. — Cheers, Steelpillow (Talk) 13:56, 12 January 2015 (UTC)

Wikipedia talk:Articles for creation/Green's function number

Dear mathematicians: Is this old AfC submission about a notable topic? The references are not on line, but perhaps someone here at this project can tell if these are appropriate. —Anne Delong (talk) 17:29, 10 January 2015 (UTC)

This article has been accepted, but it still needs a bit of cleanup and some more references. Primefac (talk) 18:42, 10 January 2015 (UTC)

Thanks, Primefac. —Anne Delong (talk) 15:21, 12 January 2015 (UTC)

A resource for English-Chinese translation of high school math terms: "Bilingual Dictionary of Mathematical Terms: English--Chinese."

If anyone is...

• Trying to translate mathematics content on the English Wikipedia into Chinese
• Trying to translate mathematics content on the Chinese Wikipedia into English
• Adding Chinese-language terminology to mathematics-related content on the Wikimedia Commons
• Trying to hold a mathematics-related discussion with a Chinese user

I have a source you can use (as long as it's high school level math - about Algebra I/Geometry level)

• "Bilingual Dictionary of Mathematical Terms: English--Chinese" (Archive; 英漢對照數學用語). New York State Education Dept., Albany. Bureau of Bilingual Education. 1988. -- See profile at (Archive) ERIC

There are also similar dictionaries for Vietnamese and for Laotian but unfortunately they are not online yet (both say "PDF pending restoration") WhisperToMe (talk) 13:42, 13 January 2015 (UTC)

WikiProject X is live!

Hello everyone!

You may have received a message from me earlier asking you to comment on my WikiProject X proposal. The good news is that WikiProject X is now live! In our first phase, we are focusing on research. At this time, we are looking for people to share their experiences with WikiProjects: good, bad, or neutral. We are also looking for WikiProjects that may be interested in trying out new tools and layouts that will make participating easier and projects easier to maintain. If you or your WikiProject are interested, check us out! Note that this is an opt-in program; no WikiProject will be required to change anything against its wishes. Please let me know if you have any questions. Thank you!

Note: To receive additional notifications about WikiProject X on this talk page, please add this page to Wikipedia:WikiProject X/Newsletter. Otherwise, this will be the last notification sent about WikiProject X.

Harej (talk) 16:57, 14 January 2015 (UTC)

Wiki page for the equation of a forced pendulum?

I'm talking about the equation discussed by Hubbard in this overview (originally published in American Mathematical Monthly, so one would assume it is a topic of sufficiently general interest). There numerous non-wiki resources for it... On wiki, Duffing equation is similarly chaotic, but does not cover it.

Also driven pendulum redirects to Kapitza's pendulum, but that's not what 99.9% of the non-wiki sources usually mean by "driven pendulum", but rather what I linked in that pdf. 86.121.137.79 (talk) 22:26, 14 January 2015 (UTC)

AfC request

Could someone please give the page at User:Inezzzzz/sandbox a look over? I've asked at two other wikiprojects as well, but I can't even begin to understand what is happening at this article. --TKK! bark with me! 23:47, 15 January 2015 (UTC)

It seems to be a notable enough topic, but the wiki presentation is poor. In a (mathematical) nutshell: "Indicator kriging is ordinary kriging of indicator variables for several cut-offs." On the other hand there are several books detailing it, including psedudocode etc., so that a sub-article may be justified. But don't ask me to write it. 86.121.137.79 (talk) 06:53, 17 January 2015 (UTC)

Finite volume methods...

This came up on the current activity page, not new but newly categorised.

• Finite volume method for three-dimensional diffusion problem

and looking I found two more very similar:

• Finite volume method for one-dimensional steady state diffusion
• Finite volume method for two dimensional diffusion problem

It's outside my area so I can't do much to them. They clearly need cleaning up but then what? Are they even notable, or just worked examples of the finite volume method? Or should they be merged, they certainly have a lot in common, not just names but similar content, similar extended links sections. Created by three different accounts, perhaps someone logging in after forgetting a password, perhaps lots of copy and paste.--JohnBlackburne^words_deeds 02:21, 21 January 2015 (UTC)

Please evaluate an AFC draft

Please evaluate Draft:Laver property for acceptability into mainspace. Roger (Dodger67) (talk) 18:10, 21 January 2015 (UTC)

The key sentence needs to be expanded or explained more. JRSpriggs (talk) 18:30, 21 January 2015 (UTC)

Is the expansion of that sentence essential for the article to pass WP:Notability? If not I can accept it into mainspace now so that normal maintenance can take care of it. Roger (Dodger67) (talk) 09:56, 22 January 2015 (UTC)

I do not know. I never heard of the Laver property before. If the Shelah reference is real, I would let it in, but I do not have his book so I cannot check it. JRSpriggs (talk) 14:36, 22 January 2015 (UTC)

Citing a preprint

(I am posting this here rather than at Wikipedia talk:WikiProject Polyhedra because that project is pretty well inactive.)

Johnson, N.W.; Geometries and transformations (2015) is actively being cited in many articles on polyhedra and related topics, in a sudden flurry of activity. Tomruen (talk · contribs) writes on his talk page that it currently exists only in PDF preprint form but it has been accepted for publication. I have in my possession an earlier draft which was circulated many years ago, and just a couple of weeks ago began removing references to it which had appeared in many of these articles. Suddenly, these are being supplanted by references to the anticipated 2015 publication. Based on past history, I am not confident that the wait for publication will in fact be a short one. Are we happy to accept Tom's word on this? — Cheers, Steelpillow (Talk) 11:19, 6 January 2015 (UTC)

I've had PDF access to the manuscript since 2011 with its final draft submitted in March 2014, and accepted in September 2014, and is in process of being reformatted with minimal content changes. I agree a preprint is problematic on verifiability. I take full responsibility if there are delays in print dates, and I'll update all reference usages as needed on final publishing. I've tried to include exact references on specific facts, and sections and titles should be fixed, but cited page numbers will likely shift a bit. Tom Ruen (talk) 21:30, 6 January 2015 (UTC)

I see not so much a problem with citing a preprint to an expert, but rather that the preprint doesn't seem to be publicly accessible. A link to it might be a valuable addition, but not a reference that is only in private circulation. Sławomir Biały (talk) 12:50, 6 January 2015 (UTC)

I've looked into this a little more, and I don't think things are quite that simple. See, for instance, 8-demicubic honeycomb. This reference has been there for a number of years, so presumably Tom Ruen relied on it to write the article. Only recently does it seem that he has updated the dates on that reference, presumably in anticipation of its imminent publication, although we can't really be sure. In an academic setting, it is necessary and appropriate to cite the sources that one uses, whatever their publication status. That seems to conflict slightly with WP:V in this case. However, I think we should allow the reference to stay there to avoid any appearance of plagiarism. Hopefully it truly will be published soon, and this whole affair will become a non-issue. Anyway, just my 2c, so YMMV. Sławomir Biały (talk) 13:27, 6 January 2015 (UTC)

I have the suspicion that a lot of the references on our polyhedra pages are pro forma "cite something generic on polyhedra because a Wikipedia article needs to have citations" rather than being specific to the subject of the article and the information they are supposedly sourcing. E.g. we have a lot of references to Coxeter's Regular Polytopes (a fine and relevant book) but without any page numbers or other identifying information that would tailor the reference to the article it appears in. So a preprint with a generic title that nobody can access is especially problematic, regardless of the reliability of its author. —David Eppstein (talk) 16:15, 6 January 2015 (UTC)

I agree entirely. I have noticed too that any challenge to some fanboy's favorite factoid tends to result in a flurry of such citations, typically also to self-published web material. There is much that needs attention. Now that we learn that Johnson's book is not yet in its final form but still being "reformatted with minimal content changes", I am even less happy about pretending on most every polytope page that it will be published this year. And what on Earth does it mean for a Wikipedia editor to "take full responsibility"? Whatever happened to biding one's time? — Cheers, Steelpillow (Talk) 22:20, 6 January 2015 (UTC)

I am not sure if this is a preprint, or just a draft submitted by the author last year - the final, corrected draft is not due until the Summer and there appears no definitive publication date. Meanwhile Tomruen (talk · contribs) continues to add new material based on this MS, including various neologisms such as adding "ditel" here. He says above that he "takes responsibility" for this, but that is meaningless because he can wait another fifteen years for it to appear if he wants to. Who is to call that "responsibility" in? Is this situation really acceptable? — Cheers, Steelpillow (Talk) 11:32, 13 January 2015 (UTC)

In that case, I answered your fact challenge with an explicit reference (Regular polytopes, p. 129) And in adding ditel, I referenced a published paper by Professor Johnson. [1] I'm not interested in bias or special treatment for Johnson's terms over any other possibilities. I'm simply giving readers an alternative term besides 1-polytope. If dyad or ditelon or any other terminology exists in usage, and reference can be made, I'd support including those as well. Tom Ruen (talk) 20:41, 13 January 2015 (UTC)

Your reference for "ditel" appears to be an unrefereed conference paper of dubious reliability. In any case, copying a term that is used in a single publication, and writing the article in such a way as to imply that this term is in general usage, was a mistake. —David Eppstein (talk) 21:39, 13 January 2015 (UTC)

BTW, Here's an example of the type of referencing I consider problematic. This edit adds three non-inline sources to the references section of an (already adequately-referenced) article; the one I can most easily check (Grünbaum and Shephard's book Tilings and Patterns) is a book reference without page numbers (see a recent discussion on this type of problem at Wikipedia talk:Scientific citation guidelines) but I have the whole book and while it does have a few pages on star polygons they do not include any mention of the specific subject of the article; I am very skeptical that the other two references contain nontrivial content about the subject either. Basically, it seems to miss the point of adding references: to make it possible to verify that the claims within the article are true and known. These references neither support any claims, nor provide any additional information about the subject of the article; they appear to be there only as a form of decoration, to make it look like the article has references. I reverted the edit for this reason but many similar sets of bad references exist in our other polygon/polyhedron/polytope articles. —David Eppstein (talk) 19:23, 23 January 2015 (UTC)

Draft reviews

Hey all - I posted these here last month, but was hoping if I could get more eyes on these drafts that have potential:

• Draft:Matrix regularization
• Draft:Loss function surrogates for classification

Thank you! ~SuperHamster Talk Contribs 06:10, 24 January 2015 (UTC)

Sum

A discussion of what to do with the redirect Sum (edit | talk | history | protect | delete | links | watch | logs | views) and the name of the article summation is occurring at talk:summation -- 65.94.40.137 (talk) 11:00, 26 January 2015 (UTC)

An editor has asked for a discussion to address the redirect Sum. Please participate in the redirect discussion if you have not already done so. 65.94.40.137 (talk) 11:26, 26 January 2015 (UTC)

Ihor Voloshyn (talk) 13:46, 26 January 2015 (UTC)

Compact finite difference

Compact finite difference is a new article that could use some cleanup, if indeed it ought to exist. Michael Hardy (talk) 03:45, 29 January 2015 (UTC)

Star polygons being saturated with images

Hi, I could use some help at Star polygon. Tomruen (talk · contribs) added a big block of images that I felt breached WP:GALLERY and WP:NOTGALLERY. I removed it and he began warring over it. After I opened a discussion on the talk page at Talk:Star polygon#gallery in the article, he continued adding more. I have posted a more detailed history of the warring there. Could some more eyes come and determine whether I am just being a grumpy old git or is Tom debasing our encyclopedia? — Cheers, Steelpillow (Talk) 10:54, 31 January 2015 (UTC)

The conflict was in the section Star_polygon#Regular compounds, and a compromise seems to have been reached. Tom Ruen (talk) 12:37, 31 January 2015 (UTC)

On the contrary, a third editor cut the gallery down drastically and Tom has since added images back in again without discussion. I am close to taking this to WP:ANI. — Cheers, Steelpillow (Talk) 13:10, 31 January 2015 (UTC)

Total lies of a confused mind. This is false. Tom Ruen (talk) 13:35, 31 January 2015 (UTC)

That goes straight to ANI at Tom Ruen warring with gross incivility. — Cheers, Steelpillow (Talk) 14:21, 31 January 2015 (UTC)

Feb 2015

Irreducibility (mathematics) needs help in a bad way

Irreducibility (mathematics) is awful as a disambiguation page, and really should either be moved to Irreducibility (disambiguation) and simplified to conform with MOS:DAB, or turned back into an article describing the primary usage of this term with respect to mathematics. Cheers! bd2412 T 18:59, 1 February 2015 (UTC)

I confess that I'm responsible for turning the page into a disambig page. I do believe there is no uniform definition of "irreducibility" in mathematics, aside from the usual English sense of "not reducible". For example, "irreducible" as in irreducible representation, one as in irreducible polynomial and one as in irreducible component (of a topological space) have nothing in common. -- Taku (talk) 00:53, 2 February 2015 (UTC)

It's not a disambiguation page. It's possibly been mislabelled as such, but it's really a collection of distinct but related uses of a term in mathematical discourse. It would certainly be ideal for someone to link to a more specific meaning of the term in mathematics, but (as often is the case) the usage of a term in mathematics often has more to do with analogies than "this usage or that one". Such pages are useful and important, but should not be treated like "disambiguation pages". If their designation as such confuses various editors, then re-designate them to a more appropriate category. Such pages are very useful and should be allowed and encouraged to stay. Taku has my full support here. Sławomir Biały (talk) 01:06, 2 February 2015 (UTC)

Ok. How do you call that page then? I have just fixed some incoming links (most of times to irreducible representation). The fix was no-brainer. It's very unhelpful for us to direct the readers to Irreducibility (mathematics) instead of "irreducible representaion", when the latter is meant in linking the term. I can ask: on what occasions do we want to have a link to Irreducibility (mathematics)? "A page that must not be linked" is more or less a disambig page. -- Taku (talk) 01:22, 2 February 2015 (UTC)

The title "Irreducibility (mathematics)" seems perfectly reasonable as a title for such a page. Why should there even be a question? I think the issue is that there is some template on that page that tells all the dab-droids that it's a disambiguation page. Remove that template, and the problem is solved, as far as I can tell. Of course, we should link as many things to a specific page as possible, using discretion. But it's wrong to say that each and every time for which the concept of irreducibility appears in a mathematics article that it needs to be completely nailed down to one of the articles. That's what a "disambiguation" page entails, and that's clearly not what we have here. Sławomir Biały (talk) 01:45, 2 February 2015 (UTC)

User:R.e.b. has fixed the problem by replacing the dab template by {{sia}}. It's not really a dab, because the thing that is ambiguous is not the word "irreducibility" but the concept: what kind of decompositions are we talking about? Set index articles are the right way to handle conceptual rather than verbal ambiguities, and don't have such severe formatting and linking constraints as dabs. —David Eppstein (talk) 02:25, 2 February 2015 (UTC)

Yes, SIA was the answer to my question (though why we need to have a distinction is beyond me, reminding me of tax code). To Sławomir, no, I think it is "wrong" to have a link to irreducibility (mathematics), because readers have to look at the list and choose the correct destination. Doesn't that make the page precise a disambig page? (or SIA as some would prefer). Anyway, the problem has been solved so it's ok now. -- Taku (talk) 12:28, 2 February 2015 (UTC)

Lewis Carroll

The page currently contains the following material:

Speculation on Dodgson's sexuality[edit] Dodgson's nephew and biographer Stuart Dodgson Collingwood wrote: And now as to the secondary causes which attracted him to children. First, I think children appealed to him because he was pre-eminently a teacher, and he saw in their unspoiled minds the best material for him to work upon. In later years one of his favourite recreations was to lecture at schools on logic; he used to give personal attention to each of his pupils, and one can well imagine with what eager anticipation the children would have looked forward to the visits of a schoolmaster who knew how to make even the dullest subjects interesting and amusing.[73] Despite comments like this, and the fact that his pictures of children were taken with a parent in attendance (many in the Liddell garden),[39] modern psychological interpretations of Dodgson's friendships with young girls and of his related work—especially his photographs of nude or semi-nude girls—have led some late twentieth century biographers to speculate that he was a paedophile, including Morton N. Cohen in his Lewis Carroll: A Biography (1995),[74] Donald Thomas in his Lewis Carroll: A Portrait with Background (1995), and Michael Bakewell in his Lewis Carroll: A Biography (1996). All of these works more or less assume that Dodgson was a paedophile, albeit a repressed and celibate one.[page needed] Cohen, in particular, claims Dodgson's "sexual energies sought unconventional outlets", and further writes: We cannot know to what extent sexual urges lay behind Charles's preference for drawing and photographing children in the nude. He contended the preference was entirely aesthetic. But given his emotional attachment to children as well as his aesthetic appreciation of their forms, his assertion that his interest was strictly artistic is naïve. He probably felt more than he dared acknowledge, even to himself.[page needed] Cohen goes on to note that Dodgson "apparently convinced many of his friends that his attachment to the nude female child form was free of any eroticism", but adds that "later generations look beneath the surface" (p. 229). He and other biographers[who?] argue that Dodgson may have wanted to marry the 11-year-old Alice Liddell, and that this was the cause of the unexplained "break" with the family in June 1863,[26] an event for which other explanations are offered. Biographers Derek Hudson and Roger Lancelyn Green (Green also having edited Dodgson's diaries and papers) stop short of identifying Dodgson as a paedophile, but concur that he had a passion for small female children and next to no interest in the adult world; in the last ten years[dated info] several other writers and scholars have challenged the evidentiary basis for Cohen's and others' speculations regarding this interest of Dodgson. In addition to the biographical works that have drawn the foregoing conclusion, there are modern artistic interpretations of his life and work that do so as well, in particular, Dennis Potter in his play Alice and his screenplay for the motion picture Dreamchild, and Robert Wilson in his film Alice. In a 2015 BBC programme The Secret World of Lewis Carroll experts indicated their belief that a photograph of a naked teenage girl, was the oldest Liddell girl Lorina, and was the work of Dodgson. The programme speculated that this was the possible cause of the break in the relationship between him and the Liddell family. Will Self in the same programme called Dodgson 'a heavily repressed paedophile. Without a doubt.' [75][76]

Note the abundance of footnotes. How much of this should be retained? Tkuvho (talk) 16:52, 2 February 2015 (UTC)

What does this have to do with the Mathematics project or mathematics? Dodgson may have been a mathematician among other things, but his biography does not have our rating template. JRSpriggs (talk) 04:45, 3 February 2015 (UTC)

Well I think it should. He did important work both in mathematics and logic. Tkuvho (talk) 14:18, 3 February 2015 (UTC)

I think this discussion is better kept at Talk:Lewis Carroll. Ozob (talk) 14:26, 3 February 2015 (UTC)

M-theory

Hello mathematicians,

I just wanted to let you all know that M-theory is currently a featured article candidate. While this is not exactly a math topic, it's related to some very exciting areas of modern mathematics such as geometric representation theory, categorification, and noncommutative geometry.

It would be great if someone here could review the article. Even if you're not an expert on math or physics, I would love to hear your views and whether you find the writing accessible.

Thanks. Polytope24 (talk) 05:01, 4 February 2015 (UTC)

Help with Covering in topology/graph theory

Hi all, I've got a handful of links that go to the disambiguation page Covering in a mathematical sense but I can't figure out which article they need to point to. Could I interest a local math maven in taking a look?

List of articles with ambiguous links to "covering"

Thanks, --JaGa^talk 21:39, 6 February 2015 (UTC)

 Done D.Lazard (talk) 10:56, 7 February 2015 (UTC)

Lie algebra extension

Do we have an article on Lie algebra extensions (under some unexpected name) or perhaps a section on it? In case we don't, and if nobody is in the process of writing one, I might write one. It would parallel group extension. YohanN7 (talk) 16:07, 5 February 2015 (UTC)

There is a section Affine Lie algebra#Classifying the central extensions, but I do not know of any standalone articles. --Mark viking (talk) 19:59, 5 February 2015 (UTC)

Thanks. For a start, I have rewritten Wigner's theorem from scratch. There are clearly connections between the subjects due to the projective representations popping up as a result of Wigner's theorem. YohanN7 (talk) 12:14, 7 February 2015 (UTC)

Navbox for "classes" of matrices?

Given that we have this neat navbox for prime number classes, I wonder if we should create a similar one for different types of matrizes. However, I'm not a mathematician (just an economist ;-) ), so apart from the ones commonly seen in economics, I don't know which of these matrices are important, let alone how to categorize a navbox. Is it a good idea though? --bender235 (talk) 15:02, 26 January 2015 (UTC)

I made Template:Prime number classes but don't think I know enough to make a proper version for matrices. I like the idea though. List of matrices may help with the grouping if somebody wants to give it a go. PrimeHunter (talk) 15:17, 26 January 2015 (UTC)

On second thought, I will make a crude version based on just copying most of List of matrices. I will post later when a draft is ready. PrimeHunter (talk) 15:24, 26 January 2015 (UTC)

I have created {{Matrix classes}} based entirely on copying every link (including red links and links with the same target) in List of matrices. Others are very welcome to make improvements. PrimeHunter (talk) 16:22, 26 January 2015 (UTC)

I think the template needs a little more focus. Right now it has too many different kinds of matrices; most of the entries have no relationship to each other besides the fact that they're matrices. A comprehensive navbox would be too big, and a suitably sized navbox is necessarily more focused. I think it would useful to have a template that discussed types of matrices that are generally of interest within linear algebra proper (sparse, banded, Hermitian, idempotent, etc.) and left out matrices which are of interest because they arise in applications (DFT, Bezout, adjacency, etc.). Ozob (talk) 04:00, 27 January 2015 (UTC)

And it looks like this:

YohanN7 (talk) 07:07, 27 January 2015 (UTC)

To give a perspective, the box looks too large, to me. I suppose it is probably hard to decide on what to include and what to exclude. (The choice would likely reflect editor's background.) -- Taku (talk) 04:30, 29 January 2015 (UTC)

Please be bold and make any improvements. I haven't added it to any articles but just wanted to quickly make a framework for others by indiscriminately copying the whole list without evaluating anything or looking for other groupings or potential additions in Category:Matrices. PrimeHunter (talk) 00:51, 8 February 2015 (UTC)

That is like asking someone to do the work for you. Will not happen. I like the thing. But it is too large, so I ask you to rinse out some. (Like stuff you've never heard of.) It can always be put back later. YohanN7 (talk) 01:02, 8 February 2015 (UTC)

Imaginary point

The article titled imaginary point has sat around for years with almost no attention. It lacks references. If the article should indeed exist, could someone cite some geometry textbook there? Michael Hardy (talk) 01:05, 5 February 2015 (UTC)

How about merging it to rational point? I have put tags proposing the merger. -- Taku (talk) 01:24, 5 February 2015 (UTC)

Call me arrogant if you like, but I can't shake the feeling that there is good reason that there are no solid references: the concept as defined in the stub appears (to me, at least) to be mathematical nonsense in the purely geometric context. I've expounded at Talk:Imaginary point. —Quondum 02:18, 8 February 2015 (UTC)

Is this award for real or is it a hoax?

Please see Stampacchia Medal. The external links do not seem to go anywhere. Is this a hoax? Having an award for such a narrow field as Calculus of variations seems unlikely to me. JRSpriggs (talk) 02:57, 8 February 2015 (UTC)

Check all the links. One of the references is [2] and one of the the external links (only linked on the pdf icon due to a syntax error) is page 17 of [3]. Clearly not a hoax. PrimeHunter (talk) 03:21, 8 February 2015 (UTC)

Here is the announcement of this year's prize by VARANA. It is real. Calculus of variations is a huge field, as it is basically calculus in infinite dimensions. It forms the foundation for both classical and quantum field theories in physics. --Mark viking (talk) 03:34, 8 February 2015 (UTC)

Thanks. Someone who knows Italian should fix the majority of the links which do not go anywhere. JRSpriggs (talk) 03:51, 8 February 2015 (UTC)

Draft help needed

Hermann Mayer is writing a draft about Rouben V. Ambartzumian and asked for help via IRC. The subject seems notable with sources such as this, but the draft is a CV that's largely based on Ambartzumian's own publications, not on what third-party coverage we have. Getting full access to the references would be a significant effort for me; thus I'd prefer if someone else could give Hermann Mayer a helping hand and improve the draft so that it can be accepted. Huon (talk) 23:55, 8 February 2015 (UTC)

Where should "Hindu numerals" redirect?

Where should "Hindu numerals" redirect, to Hindu–Arabic numeral system, or to Arabic numerals? Paul August ☎ 13:59, 10 February 2015 (UTC)

Links in Math tags

Hi,

I had a look at https://en.wikipedia.org/wiki/Wikipedia:Rendering_math with the intention to figure out what else is needed after MathML got the default rendering mode for math-tags.

I think it will take a while to get rid or the requirement that people have to learn tex. The visual math input plugin I have investigated see http://math-min.wmflabs.org/w/extensions/MathSearch/modules/min/index.xhtml produces some reasonable results, but is not production ready yet.

However, I get the feeling that the other main disadvantage Unable to place wikilinks on parts of formulae. is easy to fix.

The only question that is open to me is how to call a tex macro for that. Maybe \wref or just \w could be an option so that

<math>\wref{d:Q11379}{E}=\wref{d:Q11423}{m}\wref{d:Q2111}{c}^2</math>

Could replace https://en.wikipedia.org/w/index.php?title=Mass%E2%80%93energy_equivalence#MassEnergyEquivalence

What do you think?

PS: Even though, there are some characters that do not exists in TeX's math mode, the third disadvantage Lacks some characters (such as Cyrillic script) is already solved from my point of view. --Physikerwelt (talk) 15:19, 7 February 2015 (UTC)

My general feeling is that placing links inside math formulas is a bad idea. It interacts badly with some features of rendered math (such as the one where you can click on a formula to embiggen it), the link coloring distracts from the meaning of the formula, and often the pieces of the formula are small making the links non-obvious. It's almost always better to put links on nearby text. So I don't see this as a high priority. —David Eppstein (talk) 18:46, 9 February 2015 (UTC)

The problems mentioned in mw:Extension:Math/Roadmap#Next steps appear to be more crucial. Any progress there? --Quartl (talk) 18:58, 9 February 2015 (UTC)

Ah you are referring to the double subscript ... use braces to clarify problem. I'll double check if that's fixed in upstream and ask the ops team to deploy the fix in production. I do not want to be the judge in spacing questions. The W3C defines the sizes and spacing rules, or is there a problem with the generated MathML? --Physikerwelt (talk) 21:30, 9 February 2015 (UTC)

I wasn't referring to a specific problem mentioned on the page. Many of them result in ugly or even unreadable output and it seems the majority of them have not been resolved yet. --Quartl (talk) 21:45, 9 February 2015 (UTC)

I have created a task for double subscript bug... https://phabricator.wikimedia.org/T89044 to ensure that this will be fixed and no red error messages will appear. Unreadable and ugly are two different things to my mind. If something is unreadable, it needs to be fixed before moving ahead; Currently, I do not see anything that I could not read in my browser on that page. Ugly seems to refer to refer to personal preferences. --Physikerwelt (talk) 22:05, 9 February 2015 (UTC)

Formulas where symbols overlap or are too close together are unreadable. Ugliness is not that subjective as you think since our reference is the output produced by LaTeX. Remember that we look at these formulas every day (I have MathML enabled). For example, the extra space after inline formulas is a major headache and should definitely be removed. Could you please organize the reported bugs into subsections such as open, fixed, reported, wontfix? For some problems that cannot easily be fixed we can think of workarounds such as inserting extra brackets or spaces, but we need to know which ones. Btw. to ask all readers to install some add-on is not a solution. --Quartl (talk) 05:13, 10 February 2015 (UTC)

PS: Lately I have encountered formulas that don't display at all in MathML, currently almost all the formulas in de:Drehmatrix. Purging the page doesn't help. Seems to be a caching problem. --Quartl (talk) 06:12, 10 February 2015 (UTC)

I do not want to argue against you, but we need to differntiate between differend kinds of problems. Howerver, MathML is different from TeX and some rendering is supposed to look different by definition. This does not relate to horizontal distance bug https://github.com/mathjax/MathJax/issues/948 that has not been fixed. I'll implement your suggestion to organzie the potential problems as soon as I can. --Physikerwelt (talk) 09:39, 10 February 2015 (UTC)

"Ugliness is not that subjective ... the extra space after inline formulas is a major headache" I think the juxtaposisitioning of these two sentences maximally undermines your point. It is not possible that some minor aesthetic thing like this is a top priority. --JBL (talk) 13:35, 10 February 2015 (UTC)

No it doesn't since all I'm concerned about is readability. I encourage you to continuously enable MathML and use Firefox or another Gecko-based browser as your working environment (apologies if you are doing this already). --Quartl (talk) 14:14, 10 February 2015 (UTC)

I'm with David that the priority seems wrong; for example, it's not that too important to implement a feature so that people don't have to learn tex. Many math editors, both existing and potential, already know tex. On the other hand, some very basic features are currently lacking. Maybe it's just me but I really want a "commutative diagram" support. This is very important; in some areas of math (e.g., category theory and homological algeba), commutative diagrams are like integral signs in calculus; without them is inconceivable. Mathematics is a little more than computing integrals after all....

Finally, i don't want to just complain but would like to acknowledge how much I (and presumably we) appreciate your work on the math support. My big thanks to you for the work. -- Taku (talk) 02:30, 10 February 2015 (UTC)

I totally agree. Commutative diagrams are something that would be really nice. Howerver, I think those have to be represented as image. http://www.w3.org/TR/MathML3/chapter6.html#interf.graphics

Currently, we would need to support that for all rendering modes. If we had only one rendering mode, this is something that should be fixable much easier, e.g. by just enabeling the appropirate mathjax extension. However, to switch to only one rendering mode, we need to implement PNG to SVG conversion. See https://phabricator.wikimedia.org/T78046 for the details --Physikerwelt (talk) 09:39, 10 February 2015 (UTC)

There is a linux utility pdf2svg that's available in the Ubuntu repository, for what it's worth. In the past, I've used a hack involving an appropriate combination of pdfchop and pdf2svg. See File:Commutative diagram SO(3, 1) latex.svg for an example. (Apologies if you already know about this.) Sławomir Biały (talk) 14:11, 10 February 2015 (UTC)

Do you see align environments?

Hi!

I cannot see anything sensible in the "m=2" section of the article Abel's binomial theorem. (There seems to be some attempt to load an image of some kind; but the result just is a warbled space.) I looked at the source text, and noted that it contains a latex align environment (within wp math-mode).

Now, I could easily rewrite this; but if this is only some problem with my browser, I shouldn't. Therefore, I'd like to know whether the m=2 example is legible for the rest of you. JoergenB (talk) 18:27, 8 February 2015 (UTC)

I just took a look and everything seems fine to me. (Windows 7 - Chrome - MathJax enabled) Bill Cherowitzo (talk) 18:36, 8 February 2015 (UTC)

It looks fine to me on the iPad, iOS8, PNG rendered LaTeX. --Mark viking (talk) 18:58, 8 February 2015 (UTC)

Firefox + XP + PNG = Firefox + XP + MathML = fine. It is nice that we have so many options for math display (none of which work in full). YohanN7 (talk) 17:10, 9 February 2015 (UTC)

@JoergenB: What environment are you using? RockMagnetist(talk) 17:32, 9 February 2015 (UTC)

Firefox, possibly a too old version; under Linux, employing Fluxbox.

Thanks for your answers! Clearly, I should not try to fix this by changing the article; but instead should consult our IT experts. JoergenB (talk) 17:32, 10 February 2015 (UTC)

Could anyone please proofread my new section?

See Cauchy_product#Products_of_finitely_many_infinite_series. Thanks. --Mathmensch (talk) 16:34, 9 February 2015 (UTC)

You have left out something from most of the sums. Each of them should have a variable of summation and its lower and upper bounds. But only two of those are shown in most of the sums. So your meaning is far from clear. JRSpriggs (talk) 17:46, 9 February 2015 (UTC)

Thanks. I fixed this. --Mathmensch (talk) 09:13, 10 February 2015 (UTC)

I want to point out that a less notationally demanding approach is to use convolution: think of a series as a function on the integers with support contained in the nonnegative integers. In this viewpoint, Cauchy product is a convolution. -- Taku (talk) 20:40, 9 February 2015 (UTC)

I guess to mention convolutions in this context is advantageous, but I would still use the sum notation, because otherwise, if you want to calculate the product of the series and want a series (as needed for example in finding a non-recursive expression of a sequence using generating functions) or a number (as needed if the series are not easily calculated), you would have to insert the convolution definition, and this would be even more fiddly, so let the article do it for you. --Mathmensch (talk) 09:13, 10 February 2015 (UTC)

Thanks for fixing the lower limits of summation. However, I now notice that the conclusion which you reach for n+1 is not in the same form as the inductive hypothesis for n, even if you move the first coefficient through the sums. JRSpriggs (talk) 08:14, 11 February 2015 (UTC)

Thanks, it should be fixed now. --Mathmensch (talk) 09:23, 11 February 2015 (UTC)

Mathematics of finance

Wikipedia has many pages in the field of mathematics of finance, for example Category:Mathematical finance, and more. None of those articles belong to this project and many are project-orphaned. Just wondering why they can't call this project home? Thanks in advance, Ottawahitech (talk) 14:42, 11 February 2015 (UTC)

There is nothing wrong in principle with a mathematics of finance article being part of WP:MATH, but I think it needs to be decided on a case by case basis. Some articles, like Malliavin calculus are firmly in the math camp. Others, like Cash on cash return is about a financial ratio--the financial aspect of quantity is the important thing, not the simple division used. --Mark viking (talk) 23:04, 11 February 2015 (UTC)

Agree. (As I understand it, whether an article has been tagged for WP:MATH is merely a consequence of whether someone has bothered to so tag it.) --JBL (talk) 23:54, 11 February 2015 (UTC)

Vladimir Voevodsky, univalent foundations, and homotopy type theory

There is something funny going on at the articles univalent foundations and homotopy type theory. Apparently, Vladimir Voevodsky is editing (as User:Vladimirias) these articles, and getting some push-back from User:Foobarnix (including edit wars, etc.). I don't have time to look into the details at the moment, but probably someone uninvolved should have a look, and defuse this situation. WP:BITE is relevant. Sławomir Biały (talk) 12:49, 10 February 2015 (UTC)

It seems pretty clear here that Vladimir Voevodsky's edits are inappropriate, as they praise himself quite a bit and contain a large amount of unreferenced material/OR. However, mathematicians frequently let famous mathematicians get away with inappropriate behavior on the internet. It wouldn't be appropriate for a congressman to make similar edits about himself, or a CEO or a musician.Brirush (talk) 14:29, 10 February 2015 (UTC)

Yes, there is unreferenced material there. But, after all, he is the world's leading expert on homotopy type theory and univalent foundations. While we should certainly not allow this niche of Wikipedia to become his personal blog, I think there is also a reasonable expectation that much of this stuff is written up elsewhere in much gorier detail so, in principle, is at least reference-able. A less confrontational approach, it seems to me, would be to ask Vladimir if he can supply some better references, perhaps dropping him a note on his talk page. I'm not seeing an unduly large amount of self-praise, at least nothing that can't be fixed by normal WP:PEACOCK editing. But as I've said, I've not really had the time to investigate that closely. Sławomir Biały (talk) 14:40, 10 February 2015 (UTC)

I agree that finding references for the new material would fix the problem.Brirush (talk) 14:46, 10 February 2015 (UTC)

Hello, I would be happy to provide references to the material that you think needs further references. Please make notes on the page and I will try to supply the references.Vladimirias (talk) 22:02, 10 February 2015 (UTC)

@Vladimiras The new version with references is excellent. I withdraw everything I said, with an apology. Thanks for responding quickly!Brirush (talk) 23:28, 10 February 2015 (UTC)

response by foobarnix

The conflict of interest and presumed self praise is not the only (or even the main) issue. Of particular concern to me is an apparent tendency of Voevodsky (=VV) to couch the history of the subject in terms that mention only his own work. For example, see the edits by VV on 9 February 2015 which deleted the entire section Univalent foundations in the HoTT article with the comment, “Section on the Univalent Foundations removed since it did not contain any information about Univalent Foundations.” The purpose of that section was to report the controversy that surrounds the usage and definition of the term 'Univalent Foundations'. Many of the researchers do not agree with VV’s use of the term. For example, see Michael Shulman’s comment on 20 December 2014 beginning, “Vladimir, could you provide some evidence that UF is not a subfield of HoTT?”

A more explicit example of VV trying to frame the history of the subject occurred with his edit of edit of 1 February 2015‎ which deleted the paragraph beginning,

This includes, among other lines of work, the construction of homotopical and higher-categorical models for such type theories...

This deletion was almost immediately reverted by another HoTT researcher Peter LeFanu Lumsdaine. I could provide more examples.

VV has commented on my talk page

There is also nothing wrong with a text on a page being written by someone who is a specialist or even a creator of the subject that the page is about.

I agree. But is it usual for a scientist to add to his own biography article in Wikipedia statements such as,

In 2009 he constructed the univalent model of the Martin-Löf type theory in simplicial sets. This was a major step in the development of homotopy type theory, and led to his programme of using it as a foundation for all mathematics. In such a role he calls it univalent foundations.” [emphasis mine]

BTW, this statement has no citations.

Another problem with many of the VV edits is the lack of usable citations. Very many of his citations reference the web based GitHub repository hosting service. This blog is a truly wonderful resource for mathematicians, and VV has contributed a lot to their usefulness. But these sites are of almost no help to the typical reader–even a mathematician–and are very much an Inside baseball resource. And, typical of such blogs, many of the links are already dead (check it out).

I certainly agree that VV was perhaps the most important researcher in Homotopy Type Theory. But he is not the only one. And by his own words, for example in his Bernays lectures video of lecture 1 2 3, he is leaving the field to work on other things. And I agree that we are fortunate to have him help to write the history. But, quite frankly, some of his statements in WP are simply incorrect. --Foobarnix (talk) 00:32, 11 February 2015 (UTC)

Indeed, the objections by Foobarnix look rather convincing. Maybe, several different points-of-view should be included. Boris Tsirelson (talk) 06:55, 11 February 2015 (UTC)

At Talk:Homotopy_type_theory I have proposed a merger including all points of view, and both phrases in the title. Michael Shulman (talk) 23:33, 12 February 2015 (UTC)

Vector space

Various attempts recently have been made to rewrite the lead at the mathematics good Article vector space. I note that the lead was something that was specifically discussed in great detail at the good article nomination, the peer review, and the featured article nomination. No one has given any clear reason to rewrite the first paragraph (apart from a vague sense of excess verbosity). Now an editor who has (apparently) forgone the use of discussion pages thinks that is misleading to refer to a vector space as a mathematical structure where elements can be added together or scaled by numbers, seemingly in deference to a Bourbaki-style viewpoint that a vector space is a four-tuple $(V,F,+,\cdot )$ consisting of a set V, field F, binary operation +, and function $\cdot :F\times V\to V$ satisfying the usual rules. Is this an appropriate perspective for the lead of an article that will likely be read by high-school students with no mathematical background?

There are other issues with the proposed revision of the lead, which are rather more serious than any perceived abuse of language in the first sentence though. The most obvious issue is that a sentence there is duplicated for no apparently good reason. Secondly, the sentence "The scalars may be real numbers, complex numbers, rational numbers, or any field" is not grammatical as written (a real number is not a field). But also, it is not exactly true either: the scalars of a vector space cannot belong to any field. Rather (as it says in the Good Article version of the lead) "there are also vector spaces with scalar multiplication by complex numbers, rational numbers, or generally any field." This makes it clear that what notion of scalar one has in mind depends on the vector space.

I've reverted twice, given that the proposed revision has these obvious deficiencies. I think more eyes are needed there. Sławomir Biały (talk) 14:02, 13 February 2015 (UTC)

I wrote him a message that he is too much mathematically correct for this non-mathematical encyclopedia. Boris Tsirelson (talk) 15:12, 13 February 2015 (UTC)

Could maybe anyone proofread my next new section?

Markov's_inequality#Extended_version_for_monotonely_increasing_functions

and

Markov's_inequality#Proof_of_the_version_with_a_monotonely_increasing_function

Thanks. --Mathmensch (talk) 15:20, 13 February 2015 (UTC)

Commented there. I think it's too much detail for a non-mathematical encyclopedia. — Arthur Rubin (talk) 16:13, 13 February 2015 (UTC)

Buchstab function

Buchstab function:

• is a near orphan. Probably other articles should link to it; and
• does not tell us who Buchstab is. It says it's also called "Buchstab's function", suggesting that it's named after a person.

We don't seem to have an article listing special functions arising in analytic number theory. Should we? (We do have one on arithmetic functions; those have the positive integers as their domains.) Michael Hardy (talk) 22:01, 15 February 2015 (UTC)

Perhaps it was not obvious that the first reference of the article was a paper by Buchstab? I couldn't find much about Buchstab (probably it would be easier for someone who reads Russian) but apparently he is the same Alexander Buchstab redlinked as the advisor of Ilya Piatetski-Shapiro (and not mentioned but probably should be on Gregory Freiman). His name has been variously transliterated as Buchstab, Bukhstab, Buhštab, Bukhshtab, and probably other variations. —David Eppstein (talk) 22:50, 15 February 2015 (UTC)

I found a published obituary and from it started a new article: Alexander Buchstab. —David Eppstein (talk) 22:14, 16 February 2015 (UTC)

Lattice path categorization

I categorized Lattice path under Cat-Enumerative combinatorics, please refine as needed. Thanks. MicroPaLeo (talk) 21:44, 17 February 2015 (UTC)

Root group

I've prodded root group and abelian root group. Although there are a fair number of occurrences of the phrase "root group" in the mathematical literature, they all appear to refer to something else (more than one other thing). While the concept defined in the article makes sense mathematically (a group in which every element has a pth root, for p in some given set) it doesn't seem to be known under this name. But I'd be happy to be proven to be mistaken and get the articles properly sourced and unprodded. —David Eppstein (talk) 06:30, 18 February 2015 (UTC)

Laver property has "graduated" from AFC to mainspace

It was previously discussed here while it was a draft, now that it is in mainspace do with it as you will. Roger (Dodger67) (talk) 17:49, 18 February 2015 (UTC)

1 for hypotenuse and 90 for the angle that is opposite of the hypotenuse

the post was edit request for Pythagorean Identities:where$\sin ^{2}(x)+\cos ^{2}(x)=1^{2}$ when x is > or equal to 1 the following examples are true.I don't know if this is original research or not but it states that for all integers bigger than one and equal to one, examples: c,d,e show that the hypotenuse which faces the angle of right angle triangles is one, and 90 degrees for the angle which is opposite of the hypotenuse, and in radian: 90 degrees is${\frac {\pi }{2}}$ . I don't see these examples listed in any article concerning trigonometric functions.

c)$f^{1}(x)={\frac {1}{x}}+{\frac {x-1}{x}}=1$

d)$f^{2}(x)=\sin ^{-1}{\sqrt {\frac {1}{x}}}+\sin ^{-1}{\sqrt {\frac {x-1}{x}}}=90$

e)$f^{3}(x)=\cos ^{-1}{\sqrt {\frac {1}{x}}}+\cos ^{-1}{\sqrt {\frac {x-1}{x}}}=90$

f)${\sqrt {\frac {x-1}{x}}}$

where ${\sqrt {x-1)}}$ is a slope and included in $\tan ^{-1}{\sqrt {x-1}}$

199.7.157.45 (talk) 15:32, 5 September 2014 (UTC) Although this is original research,It fits in the discussion of trigonometry project group because it's a fact for a right angle triangles to have the bigger angle to be the inverse of the tangent $\sin \tan ^{-}1(4)$ and for the smallest angle it's inverse of tangent $sin\tan ^{-}1{\frac {1}{4}}$, the tangent being the inverse of the slope or the biggest angle,where the biggest angle being 90 degree.Trenteans123 (talk) 08:55, 19 February 2015 (UTC)

cos A={c^2+b^2-a^}/{2×b×c}

c^2=a^2+b^2

New bug in our math notation rendering

The align environment has lately begun to put an inappropriate lack of spacing in this like this:

\begin{align}
a & = some expresion \\
& = some other expression
\end{align}

Thus:

${\begin{aligned}a&={\text{some expresion}}\\&={\text{some other expression}}\end{aligned}}$

There should be a space between a and "=", but it's not there. Michael Hardy (talk) 22:37, 15 February 2015 (UTC)

What math rendering preferences and browser are you seeing this in? It looks ok to me with client-side mathjax as well as not-logged-in. —David Eppstein (talk) 22:52, 15 February 2015 (UTC)

I can confirm the bug. I'm on iPad with MathML with png and I see no space between a and =. -- Taku (talk) 00:04, 19 February 2015 (UTC)

Png + Firefox on XP desktop = ok. YohanN7 (talk) 06:35, 19 February 2015 (UTC)

Please file a bug report —TheDJ (talk • contribs) 12:14, 19 February 2015 (UTC)

Comment on Draft:Sacks property wanted

I can't speak for the other editors having reviewed Draft:Sacks property, but I can say frankly that I am not able to pass a qualified judgement. Could some of you gals/guys add a comment here that I can pass on? Or review it yourself? Thanks, -- Sam ^Sing! 18:12, 19 February 2015 (UTC) (please  mention me on reply)

It looks like a typical short new article in research mathematics. The fact that Shelah put the subject of the article in the title of one of his papers is enough by itself to convince me that the topic is notable. It's quite WP:TECHNICAL, but perhaps unavoidably so considering its subject matter. So while some improvement would be welcome, I don't see any reason to prevent its creation. —David Eppstein (talk) 18:33, 19 February 2015 (UTC)

@Sam Sailor:, I agree. --JBL (talk) 18:35, 19 February 2015 (UTC)

Thank you David Eppstein and Joel B. Lewis. Did you get a ping from my use of {{U}}? I did not get one from JBL's use of {{reply to}} above. Similar to Sacks property, could you comment on Draft:Kane's Method. -- Sam ^Sing! 21:36, 19 February 2015 (UTC)

I did get the ping, yes. Re Kane's method: too equation-heavy and too much unsourced material to accept yet. It should be cut down to a description of the method, not a derivation of it, and ideally every paragraph should have at least one footnote. —David Eppstein (talk) 22:06, 19 February 2015 (UTC)

Thanks, I'll pass your comment on. -- Sam ^Sing! 23:21, 19 February 2015 (UTC)

Is this web source adequate?

This web source: http://faculty.kutztown.edu/schaeffe/Tutorials/General/Polygons.html is being used to verify a long list of pretty names for naming polygons. Does this source represent, a) a reliable authority and b) sufficient use to establish the encyclopedic value of such a list? — Cheers, Steelpillow (Talk) 16:11, 14 February 2015 (UTC)

I'm happy to improve the published documentation, and ordered one mathematics dictionary to see if it'll help, but so far the referencing is basically up to 20-gon which all have articles. There's certainly some sources if you want to go to old books like this 1888 one on GoogleBooks, not to say old names are going to help what's used in modern books. [4] Tom Ruen (talk) 17:18, 14 February 2015 (UTC)

It's a plausible naming method, but not one I've seen before. In fact, to the best of my recollection, I've never seen the string "kai" within a word in a mathematical paper before. On the whole, I wouldn't consider it a reliable source, unless schaeffe's credentials can be established. I'm pretty sure I've seen pentaicosagon for a 25-gon. — Arthur Rubin (talk) 18:15, 14 February 2015 (UTC)

Regardless of the reliability of the personal web page of an obscure mathematics professor on subjects concerning ancient Greek nomenclature, I think the fact that this level of sourcing is the best that can be found for these names indicates that they are not in common use and should not be described on Wikipedia as if they are in common use. —David Eppstein (talk) 18:16, 14 February 2015 (UTC)

If Coxeter were still around, we could ask what reference he used. But I can't think of a way that we could now possibly determine "common use" for numbers over 20, except possibly 30, 40, 50, 60, 100, 1000, and 10000. — Arthur Rubin (talk) 18:27, 14 February 2015 (UTC)

Textbooks might be good.... — Arthur Rubin (talk) 18:41, 14 February 2015 (UTC)

I'll keep looking. A web source credited to John H. Conway is here [5], and George W. Hart repeats here [6]. Norman W. Johnson has web source copied here [7]. Johnson's names are more used with the polyhedra and 4-polytopes, like pentagonal hexecontahedron for a 60-hedron, pentagonal icositetrahedron for a 24-hedron, rhombic triacontahedron for a 30-hedron, tetracontoctachoron for 48-cell, and hecatonicosachoron for 120-cell, etc. So whatever varied systems are in use in polygons, polyhedra or higher, I think they can be traced and documented in some agreeable format. Tom Ruen (talk) 18:46, 14 February 2015 (UTC)

And I'd suggest that that is the core of the problem. No one system stands out as mainstream, they are all just different fringe suggestions. — Cheers, Steelpillow (Talk) 20:11, 14 February 2015 (UTC)

Luckily, the only articles we have on polygons with over 20 sides are 24, 30, 257, 1000, 65537, and 10⁶. Of these, chiliagon (1000) has the best sourcing: the name goes all the way back to Descartes (except that he uses chiliogon), along with myriagon (Descartes: myriogon, 10000). The articles for 257 and 65537 just use the n-gon naming, so there is no problem there. Megagon (10⁶) is a little shaky: no doubt it deserves an article, given the multitude of sources using it as an example; but it doesn't seem to be called "megagon" usually (and linguistically, it's a little shaky as "mega-" meaning 10⁶ only started with SI). Instead a descriptive phrase along the lines of "polygon with a million sides" seems to get used instead. Icositetragon (24) and triacontagon (30) could be justified as fortunately these are prefixes that you find in common names for some polyhedra (e.g. deltoidal icositetrahedron, rhombic triacontahedron). Double sharp (talk) 04:24, 15 February 2015 (UTC)

Triacontagon is safe! Coxeter uses it in Regular Polytopes (p.249). And this (Topics in Mathematics for Elementary Teachers: A Technology-Enhanced Experiential Approach by Sergei Abramovich) gives (p.89) pentadecagon (15), hexadecagon (16), octadecagon (18), icosagon (20), icositetragon (24), triacontagon (30), and tetracontadigon (42). Dr. Euler's Fabulous Formula: Cures Many Mathematical Ills by Paul J. Nahin gives (p.46) icosagon (20), triacontagon (30), and tetracontagon (40), as well as giving up for the 5242880-gon ("?-gon"). Double sharp (talk) 04:31, 15 February 2015 (UTC)

I'm not surprised that up to triacontagon can be properly sourced. The rhombic triacontahedron is pretty well known. It's some of the higher ones, like 42 and 46 in the table below, that I'm more dubious about. (It's plausible we might have a name for the 96-gon, though, as that's the one Archimedes used to approximate π.) —David Eppstein (talk) 08:06, 15 February 2015 (UTC)

The Handy Math Answer Book by Patricia Barnes-Svarney and Thomas E. Svarney gives a table of names (pp.413–4). So far all the names I found sources for are below: they're all from the Svarney list except for: 1-gon (Coxeter, Regular Maps, p.388), 24-gon, 42-gon (Abramovich), 1000-gon, 10000-gon (the second ones from Descartes), and 1000000-gon (sources at megagon; this is kind of a fringe name, as I can't find many sources deriving it, but I do not think there is any other Greekish name for it).

I think this table includes the only names that would get derived regularly (and 24, 42, 46, 10⁶ are just from one-off occurrences). I doubt any other polygons have been named anything other than n-gon, except perhaps as examples for name construction like 46-gon here.

1	Monogon
2	Digon
3	Trigon, triangle
4	Tetragon, quadrilateral
5	Pentagon
6	Hexagon
7	Heptagon
8	Octagon
9	Enneagon, nonagon
10	Decagon
11	Hendecagon, undecagon, unidecagon
12	Dodecagon
13	Tridecagon, triskaidecagon
14	Tetradecagon, tetrakaidecagon
15	Pentadecagon, pentakaidecagon
16	Hexadecagon, hexakaidecagon
17	Heptadecagon, heptakaidecagon
18	Octadecagon, octakaidecagon
19	Enneadecagon, enneakaidecagon
20	Icosagon
24	Icositetragon
30	Triacontagon
40	Tetracontagon
42	Tetracontadigon
46	Tetracontakaihexagon
50	Pentacontagon
60	Hexacontagon
70	Heptacontagon
80	Octacontagon
90	Enneacontagon
100	Hecatontagon, hectogon
1000	Chiliagon, chiliogon
10000	Myriagon, myriogon
1000000	Megagon

While an extrapolation of the way Svarney constructs 46-gon (tens + kai + units for 21- to 99-gon) would give icosikaitetragon for 24-gon and tetracontakaidigon for 42-gon, they do not spell these out, and it appears that these names are not used at all barring one or two occurrences. (The top result for icosikaitetragon on Google Books is a mistake: the object being discussed is a polyhedron, so it should really be icositetrahedron or icosikaitetrahedron.) Double sharp (talk) 07:29, 15 February 2015 (UTC)

Standard names

OK, so after searching for a while on Google Books, it looks like the following are the only names that seem to be standard (in that they will often appear in a listing of polygon names, and do not vary much between sources):

#	Standard name
1	Monogon
2	Digon
3	Trigon, triangle
4	Tetragon, quadrilateral
5	Pentagon
6	Hexagon
7	Heptagon
8	Octagon
9	Enneagon, nonagon
10	Decagon
11	Hendecagon, undecagon
12	Dodecagon, duodecagon
13	Tridecagon, triskaidecagon
14	Tetradecagon, tetrakaidecagon
15	Pentadecagon, pentakaidecagon
16	Hexadecagon, hexakaidecagon
17	Heptadecagon, heptakaidecagon
18	Octadecagon, octakaidecagon
19	Enneadecagon, enneakaidecagon
20	Icosagon
24	Icositetragon
30	Triacontagon
40	Tetracontagon
50	Pentacontagon
60	Hexacontagon
70	Heptacontagon
80	Octacontagon
90	Enneacontagon
100	Hecatontagon, hectogon
1000	Chiliagon
10000	Myriagon
1000000	Megagon
∞	Apeirogon

I've bolded the names I think we should use on Wikipedia. They're all articles, except 50-, 60-, 70-, 80-, 90-, and 100-gon. (I'm choosing "hecatontagon" over "hectagon" because the former is closer to the etymological source. They usually appear together as alternatives, but "hectagon" seems more popular on Google Books because it's a common typo and has been used for different meanings. Incidentally, alternative meanings are also why "megagon" has so many hits.)

Hmm, reconsidering: MathWorld and Wolfram Alpha appear to understand hectogon and not hecatontagon, and "hecto-" is more familiar as it's already an SI prefix (albeit not a commonly used one). So, changed my recommendation to hectogon. Double sharp (talk) 10:51, 18 February 2015 (UTC)

On my choice of nonagon over enneagon for the 9-gon: this was a bit difficult, as enneagon is etymologically superior and it fits well with enneadecagon and enneacontagon (where the nona- forms are just about unknown). But I went for nonagon because it's much more common, and because enneagon seems to often have non-mathematical connotations. Double sharp (talk) 10:34, 18 February 2015 (UTC)

What is just as important as giving the list itself is giving the sources from which you derived it. That way interested people, be they fellow editors or visiting readers, can check for themselves that the sources both support the names and are adequately reliable. There is no harm in giving two names if they are both verifiably significant. — Cheers, Steelpillow (Talk) 16:25, 18 February 2015 (UTC)

Here's some: one two three four. This (Dr. Math) might not absolutely qualify as an WP:RS, but is useful in that it agrees with the other lists, thus showing that at least for the numbers of sides I posted there are standard names. (Megagon isn't in any of these lists, but sources for that are on its article, and it does not appear to have any other name in common use.) Double sharp (talk) 05:18, 19 February 2015 (UTC)

Here's an old list from Charles Sanders Peirce, which seems to attempt to go very close to the original Greek (hence following Johnson's forms pentecontagon, hexecontagon, hebdomecontagon, ogdoëcontagon, enenecontagon, and creating new coinages like tessaragon). These, I guess, are referenceable alternative names.

As for the notability of these polygons: I originally thought of a strict cut-off at 12-gon, and strict demands for any higher ones to show their notability, but it seems clear from my 2012 AfD that this is never going to get consensus. So I think perhaps we could simply have an article on every polygon that has a standard name (i.e. a name that is used and agreed on by multiple sources), plus 257-gon and 65537-gon (as these have obvious notability). Double sharp (talk) 05:23, 19 February 2015 (UTC)

OK, carried out that plan: now everything with a standard name gets an article (only the ones in the table above), and nothing else does. Double sharp (talk) 07:53, 19 February 2015 (UTC)

Here's three that only occurred once: tetracontadigon for the 42-gon (first reference above), triacontakaidigon for 32-gon and hexacontakaitetragon for the 64-gon (here) So these names could be mentioned, but the primary usage should be just 32-gon, 42-gon, and 64-gon. Double sharp (talk) 05:41, 19 February 2015 (UTC)

P.S. I have no doubt that both names should be given usually, but the article can only be at one of them (with a redirect from the other), and it becomes irritating to keep saying "tetradecagon or tetrakaidecagon". Double sharp (talk) 07:05, 19 February 2015 (UTC)

One more source (except 14, 19, 24, 10⁶). Double sharp (talk) 07:10, 19 February 2015 (UTC)

All of those sources that I can access given simply list a few example polygons (one or two refused access). That does not make them notable enough for their own articles. For that, they need some unique and notable discussion, as for example the chiliagon has received (hence the failure of that RfD). Even for a simple listing in the polygon article, several of those alternative names are clearly obscure (to coin a phrase) and, per WP:UNDUE, should not be included. The fact that people are scratching around the Internet seeking - and failing to find - sources to bolster their claims does not bode well for those claims. — Cheers, Steelpillow (Talk) 08:50, 19 February 2015 (UTC)

Yes, chiliagon should indeed have been kept (although that didn't seem so clear at the beginning of the AfD), but somehow all the articles like tridecagon also managed to be kept despite lacking much unique and notable discussion (a list of polygons articles seems like an interesting solution).

Of course they only list a few example polygons. Isn't that the point? And I'd argue that the use of these names in single instances, like "triacontagon" or "40-gon (tetracontagon)", but not in crazy cases like the 5242880-gon, speaks in favour of the fact that tetracontagon is standard for the 40-gon but something like pentacosiicositetrakismyriadischiliaoctacosioctacontagon isn't for the 5242880-gon.

The third and fourth ones I linked to give a large table with all names from 3–20, and then in tens from 30–100, and then 1000 and 10000. Given that two sources are deriving these particular names in exactly the same way seems to speak well for their being standard. Here is another that uses exactly the same names up to 100, and MathWorld (in its form as the CRC Concise Encyclopedia of Mathematics) also uses the exact same names, so that's four already using the same names. Standard? I think so. The fourth source even provides a general system to make every name from 21- to 99-gon, but you'll notice I didn't add it as this system doesn't seem to have been repeated explicitly elsewhere (and isn't always followed – note their use of "-kai-", which seems not to be the common form for the 24-gon).

You'll notice I didn't include all of Peirce's names, which contain lots of etymologically correct but unused things like heccædecagon (16-gon); I only included his names for 40-, 50-, 60-, 70-, 80-, and 90-gon because these were taken up and proposed again by Conway and Johnson (true, their endorsement isn't in RSes yet, but given that they are following something stated in an old RS it should count for something). So it seems to satisfy the second condition under WP:UNDUE: the names from tessaracontagon to enenecontagon may be a minority view, but it is easy to name prominent adherents, so it seems to be a significant enough minority, something that heccædecagon doesn't qualify for. Double sharp (talk) 03:07, 20 February 2015 (UTC)

I guess that every polygon has a different story to tell and we just have to take them one at a time. The problem we face is that some editors have boundless energy and a habit of going, "look at this piece of belly-button-fluff I found in this obscure paper, it simply has to go on Wikipedia" and before you know it, it is across a dozen articles and more, with a degree of OR worked in for luck. An example of this is where this discussion topic came in. Is there any way to contain such uneducated and ill-considered enthusiasm? — Cheers, Steelpillow (Talk) 11:08, 20 February 2015 (UTC)

Root group

Should Root group and Abelian root group be deleted? Michael Hardy (talk) 18:05, 20 February 2015 (UTC)

See four sections up in this talk page. —David Eppstein (talk) 21:50, 20 February 2015 (UTC)

Just for the record, I tried to find in-depth references for root group, but failed. There are mentions out there, some corresponding to the prose in the article, but nothing that would demonstrate notability. It seems somewhat related to a p-group, but I don't know the field well enough to determine if a redirect is warranted. --Mark viking (talk) 22:41, 20 February 2015 (UTC)

Any comments on Draft:Cokurtosis?

Comments on Draft:Cokurtosis are welcomed. Use Preferences → Gadgets → Yet Another AFC Helper Script, or use {{afc comment|your comment here}} directly in the draft. -- Sam ^Sing! 00:00, 23 February 2015 (UTC)

This submission looks fine, except for the minor stylistic issue that the "Properties" section shouldn't be a list of bullets. Ozob (talk) 03:39, 23 February 2015 (UTC)

Adding a Proof template?

I tried to start a discussion on the talk page of Wikipedia:WikiProject Mathematics/Proofs to add a template Proof (see suggestion). This page seems to have unfrequent visitors as no answer has been posted in one month, so I thought I would post to here to gain more discussion. Here is what I would like to suggest:

Suggestion originally posted on Wikipedia_talk:WikiProject_Mathematics/Proofs The guidelines page on proofs mentions the possibility to use collapse boxes to include non-essential proofs. I was wondering whether it would make sense to have a specific template for this, as (for example) the french wikipedia has: fr:Modèle:Démonstration ? Are there reasons for this not to be used also in the English wikipedia? Note I am asking about this, although I would not be able to implement it myself. EtudiantEco (talk) 05:24, 11 January 2015 (UTC)

EtudiantEco (talk) 06:04, 25 February 2015 (UTC)

Wikipedia:Core math, science and technology topics

Someone from this project may be interested in reviewing and cleaning up the two lists of maths articles here: Wikipedia:Core math, science and technology topics. Not only is calendar included in the top nine articles, but the top six articles are not a subset of the top nine --76.14.68.103 (talk) 07:31, 23 February 2015 (UTC)

I edited the top 9 list so that it wasn't so ridiculous. However that page hasn't seen any edits since June 2013 so I'm not sure it's being used for anything anymore. Ozob (talk) 12:48, 23 February 2015 (UTC)

This does rather duplicate Wikipedia:Vital articles#Mathematics (55 articles), I'm not sure what the purpose of the core list is.--Salix alba (talk): 07:16, 25 February 2015 (UTC)

In a semi-joking defence of "calendar", for thousands of years, a central preoccupation of mathematicians was to establish "calendars" (that is, to ascertain patterns in the heavens for marking time). This is no small achievement of mathematics, given that the same kind of patterns were discovered, in many cases independently, by every ancient civilization on the planet. Sławomir Biały (talk) 19:37, 25 February 2015 (UTC)

Smooth maximum is an orphan

No articles currently link to smooth maximum. Michael Hardy (talk) 02:35, 26 February 2015 (UTC)

General complaint 608

On Examples

IN WHICH an article talks about a structure, and most (if not all) of the examples of the structure are examples of a special case.

Do we need to list the letters P, Q, and the number 6 as being bogus? And explain why they are bogus? Is it not sufficient to just say "All garthices (such as the letters P, Q, and the number 6) are bogus?"

If we took an axe to these examples, the resulting article would often be content-free, and I am tempted to conclude the examples were added just to disguise the lack of content. --192.75.48.8 (talk) 16:11, 25 February 2015 (UTC)

Can anyone decipher this? --JBL (talk) 16:21, 25 February 2015 (UTC)

Proposing removal of content from sections as per deletion process outlined inWP:POINTLESSEXAMPLES#MATHEMATICS. Something something consensus, something encyclopedic something? --192.75.48.8 (talk) 16:30, 25 February 2015 (UTC)

No, not at all. Maybe the poster could give an example article?MicroPaLeo (talk) 16:41, 25 February 2015 (UTC)

The second comment makes me think it's just trolling. --JBL (talk) 16:59, 25 February 2015 (UTC)

I thought so, but the IP made a good edit in an article, so it seems worthwhile trying to find out if there is more. You could be right. MicroPaLeo (talk) 17:02, 25 February 2015 (UTC)

The first sentence has a point: suppose in an article on group theory, all the examples given are Abelian. While not wrong, the examples leave out an important class of groups. It would be good for the poster to provide pointers to articles where this is the case. The second point I think is kvetching about math articles that list a bunch of examples of a mathematical structure without well-describing properties of the structure itself. I have seen article like this, too. Both of these are just a fact of life on WP: articles are incomplete and could use improving. --Mark viking (talk) 17:20, 25 February 2015 (UTC)

One might lodge the same complaint against just about any treatment of groups for someone totally unfamiliar with the concept. The classic undergraduate texts of Hungerford and Herstein come to mind. For pedagogical purposes, it is often useful to focus first on a special case that does not contain all of the nuances of the full theory. Sławomir Biały (talk) 19:32, 25 February 2015 (UTC)

All examples of anything are necessarily special cases. Michael Hardy (talk) 02:37, 26 February 2015 (UTC)

But one should take care when selecting examples. Quercus durata, would not be a good example for the sole species in the lead section of an article or if only a small number of species were mentioned in a short article on section Quercus of the genus. 'Q. alba could be ideal in the lead, but one could use Q. douglasii or Q. virginiana or Q. arizonica as examples, all of which are also endemics. If not as desirable as Q. alba or Q. robur, they would be good additional mentions, could be reasonable examples, and not bad choices like Q. durata. Not all special cases are equal. Although this is a biology example, and in math one may have a case where all examples are equal, you mention "special cases," meaning they are not. Examples should be chosen with care and clearly show understanding of the topic. MicroPaLeo (talk) 04:30, 26 February 2015 (UTC)

Stars and bars (combinatorics)

In Theorem two, the solution of the problem is ${\tbinom {n+k-1}{n}}$? I think it's ${\tbinom {n+k-1}{k}}$. --Eric4266 (talk) 03:47, 26 February 2015 (UTC)

You are thinking of ${\tbinom {n+k-1}{k-1}}$ (you are dividing objects into k sets, so you need k − 1 separators). This is equal to the solution given in the article. See the proofs section of the article. Ozob (talk) 13:40, 26 February 2015 (UTC)

Polyadic space

Polyadic space is a new article. Currently no other articles link to it. Michael Hardy (talk) 20:50, 15 February 2015 (UTC)

I have added links to it from Alexandroff extension and Dyadic space. --Joshua Issac (talk) 14:56, 27 February 2015 (UTC)

Mar 2015

Special character inserter for VisualEditor

VisualEditor’s special character inserter has been re-designed. The old “floating box” version will be replaced by the new, full-width design on Wednesday, 11 March – unless editors decide that they prefer the old one in time for it to be yanked out of the deployment train. This affects only VisualEditor. If you'd like to see the new design, then please click here to open the Sandbox at mediawiki.org. Leave your feedback at the VisualEditor/Feedback page on mediawiki.org.

I wanted to get this to you as soon as possible, so that anyone who is interested would have as much time as possible to think about the general concept. There are a few known problems that you'll want to keep in mind:

• As of this morning, this sandbox only shows a small, basic set of special characters. However, the list of characters can be customized at each wiki, and, unlike the old design, it should be possible to expand it without filling the whole screen.
• There is a known bug about the special character tool (neither the old one nor the new one) not working inside most of the tools, including the Formula editor. This will be addressed separately.

The devs need a wide variety of feedback, but the main question is whether this general concept is better than the original concept. Please post your comments at mediawiki.org, where the devs will see them sooner. Thank you! Whatamidoing (WMF) (talk) 19:26, 5 March 2015 (UTC)

Apeirotope: factual accuracy

Perhaps someone here can contribute to the factual-accuracy issue I raised at Talk:Apeirotope. Michael Hardy (talk) 19:22, 8 March 2015 (UTC)

I wish it were the only article on polytopes that deserved such a tag. — Cheers, Steelpillow (Talk) 20:22, 8 March 2015 (UTC)

Draft:Discrete-Stable distribution

Your comments on Draft:Discrete-Stable distribution are welcomed. Use Preferences → Gadgets → Yet Another AFC Helper Script, or use {{afc comment|your comment here}} directly in the draft. -- Sam Sailor ^Talk! 23:27, 8 March 2015 (UTC)

Draft:Kirkwood-Buff solution theory

Your comments on Draft:Kirkwood-Buff solution theory are welcomed. Use Preferences → Gadgets → Yet Another AFC Helper Script, or use {{afc comment|your comment here}} directly in the draft. -- Sam Sailor ^Talk! 00:31, 9 March 2015 (UTC)

This is a physics article. WT:PHYSICS would provide better advice. Ozob (talk) 02:48, 9 March 2015 (UTC)

Thanks, draft is now in mainspace. -- Sam Sailor ^Talk! 18:28, 10 March 2015 (UTC)

Draft:Polynomial least squares

Your comments on Draft:Polynomial least squares are welcomed. Use Preferences → Gadgets → Yet Another AFC Helper Script, or use {{afc comment|your comment here}} directly in the draft. -- Sam Sailor ^Talk! 18:29, 10 March 2015 (UTC)

Coin problem and postage stamp problem

Before I think about trying to merge them, I thought I should check: is there any reason that these are two separate articles? --JBL (talk) 14:23, 12 March 2015 (UTC)

Although these problems are very similar, they are distinct. The number of stamps one can use has an upper bound, but there is no upper bound for the number of coins one can use. In the case of stamps, one is looking for a minimum. In the case of coins, one is looking for a maximum. They should link to each other and they do. I see no need to merge them. JRSpriggs (talk) 14:55, 12 March 2015 (UTC)

Thanks! I think I was thrown by the recently-added (and false) statement in the lead of postage stamp problem that asserted it was given by the Frobenius number. I've now removed that statement, and all seems well. --JBL (talk) 15:14, 12 March 2015 (UTC)

LaTeX versus HTML again

Could anyone weigh in at Talk:Hilbert transform regarding LaTeX versus HTML issues? I'm not sure what our current recommendation is regarding inline mathematics (presumably {{math}}). It seems like Hilbert transform has made something of an effort to avoid rendering inline PNG images, and now someone wants to change that. Sławomir Biały (talk) 12:46, 2 March 2015 (UTC)

It does not make sense to call any of the software used here "LaTeX". LaTeX does typesetting; it keeps track of page numbers, section numbers, etc., one can use style files in it that control all sorts of formatting and stylistic things. One can use mathematical notation in it, and the code largely looks like what is used on Wikipedia, but that is light-years away from meaning that what's done on Wikiepdia is LaTeX. Michael Hardy (talk) 17:05, 6 March 2015 (UTC)

Ok. But that doesn't really suggest an alternative. I propose "PigTeX" (for Pidgin LaTeX). Sławomir Biały (talk) 23:32, 12 March 2015 (UTC)

Wikipedia:Articles for deletion/Probabilistic solution discovery algorithm

Opinions are now timely at Wikipedia:Articles for deletion/Probabilistic solution discovery algorithm. Michael Hardy (talk) 18:24, 13 March 2015 (UTC)

Always a link to namesake?

In general, Foo's Theorem or Bar's Constant should contain a link to the Mathematician (Foo or Bar) who it is named for, right?Naraht (talk) 18:24, 11 March 2015 (UTC)

Seems reasonable in the abstract; is there some dispute involving a particular example? --JBL (talk) 18:33, 11 March 2015 (UTC)

(edit conflict) True if the mathematician has an article, but not necessarily if the mathematician is known only for this theorem or constant (see WP:1E). In any case, please, avoid red links, unless if you plan to write the article in a near future. In the other case, instead of a link, add a single sentence saying who is this mathematician. D.Lazard (talk) 18:37, 11 March 2015 (UTC)

No Redlinks intended, just missed that something that I thought was an article of that type was a redirect.Naraht (talk) 18:46, 11 March 2015 (UTC)

(edit conflict) Also, it is not necessary and often harmful to interpolate, distracting the reader who might not even remember how the sentence started, the link to the namesake into the first sentence of the article. Better to include only the more important information about the subject in the first sentence (like what it is), and mention the namesake only later in the first section. —David Eppstein (talk) 18:49, 11 March 2015 (UTC)

I agree with David. Generally, we should include the namesake somewhere in the lead of the article, but not generally in the first sentence. The first sentence has a tough enough job already without overburdening it with mandatory details. Sławomir Biały (talk) 19:15, 11 March 2015 (UTC)

I disagree with D.Lazard about red links. I think:

• Red links are appropriate if existence of an article on the topic is appropriate and the link is relevant to the article in which it appears. And I seem to recall that that is a Wikipedia policy.
• Regardless of whether an article ought to exist about John Xmith, after whom Xmith's theorem is named, the article titled "Xmith's theorem" should say who it's named after.
• Our convention is _not_ to write "Xmith's Theorem" or "Zmigh's Constant" but "Xmith's theorem" with a lower-case "t" and "Zmight's constant" with a lower-case "c".

Michael Hardy (talk) 18:30, 13 March 2015 (UTC)

Ldecalmer

I do not oppose or support their edits, but we may need to clean up pages so the article structure makes sense. —George8211 / T 10:48, 14 March 2015 (UTC)

This appears to refer to the creation of large numbers of articles on numbers in the range 701–899. It appears all have been restored to be redirects again, and Ldecalmer (talk · contribs) has been blocked for disruptive editing. —David Eppstein (talk) 15:29, 14 March 2015 (UTC)

Draft:Generalized Functional Linear Model

Hi at WP:AFC there is a draft called Draft:Generalized Functional Linear Model. To me it looks as if it is a valid topic. But could some here keen on Statistics take a look to see if the content looks valid? Graeme Bartlett (talk) 06:12, 17 March 2015 (UTC)

Any way to update the 500 most frequently viewed articles list?

I'd be interested in updating the list found at https://en.wikipedia.org/wiki/Wikipedia:WikiProject_Mathematics/Wikipedia_1.0/Frequently_viewed/List, which was last edited in 2009. Does anyone know what methods I can use to find the most-viewed mathematics articles as of this year?Brirush (talk) 18:27, 17 March 2015 (UTC)

You probably know this, but anyways; from "page information" you can find "page view statistics" and see the number of views per day in diagram form. It remains to find out how this info can be gathered easily for all math articles, summed up over a period of time, averaged, and ordered. YohanN7 (talk) 18:59, 17 March 2015 (UTC)

I guess there is a bot that does this, you might want to inquire at the technical village pump. If you feel like doing it yourself, all page view data is collected at http://dumps.wikimedia.org/other/pagecounts-raw/; it is a lot of data to download, then you would have to filter according to a current list of math articles, and sort. It might be easiest to try to track down the bot. --Mark viking (talk) 21:43, 17 March 2015 (UTC)

Template:Sfrac

What are our opinions on the template {{sfrac}}? This produces fractions in html, like a/b. It was recently deployed at Pi. I have two concerns over the use: one is that it enlarges the line spacing between adjacent text lines, which overall is rather unsightly. Secondly, I noticed that in chrome on my mobile, the vinculum is the baseline of the surrounding text, which is much too low, giving inline expressions a very lopsided appearance. My impression was that once upon a time, we recommended against using PNGs that were tall enough to mess with the line spacing. If so, perhaps this template should indicate that it should only be used sparingly inline, if at all. The recent additions of the template at Pi seem rather gratuitous. For instance, 22/7 instead of a perfectly acceptable 22/7. Sławomir Biały (talk) 21:18, 15 March 2015 (UTC)

MOS:FRAC is the leading guideline. It allows both methods. -- [[User:Edokter]] {{talk}} 22:19, 15 March 2015 (UTC)

Sławomir's question is about opinions of style (which could influence the MoS), not about what the MoS currently says. I share the concern about the template, and any other formatting that does not keep line spacing uniform. My Firefox browser on my mobile does something else that's even worse: it vertically stacks a 22 over a solidus over a vinculum over a 7, with a full line gap from previous line. I think that the MoS should prefer the 22/7 format in general due to the line spacing effect on all browsers. —Quondum 01:01, 16 March 2015 (UTC)

In most inline equations, and certainly for 22/7, a solidus is superior to a vinculum. (In displayed equations, the vinculum may be superior.) A vinculum widens the vertical spacing and requires the numerator and denominator to be in a small font. If an equation would be easier to read with a vinculum, that's a sign that the equation should be displayed instead of being inline. For that reason I think the desirable uses of {{sfrac}} are highly limited. Ozob (talk) 14:34, 16 March 2015 (UTC)

I tried another experiment to see how {{sfrac}} looks on the desktop versus mobile site. On the desktop site (as viewed from a mobile device), the vinculum is too low (as already noted). But on the mobile site, it is completely broken. See [8]. Sławomir Biały (talk) 15:21, 16 March 2015 (UTC)

I'm not sure where the right place to bring this up is. It seems to me that our MOS should not unreservedly recommend this template, since it is broken on the mobile site (which constitutes 30% of Wikipedia views). My suggestion is that the MOS should indicate this, and recommend that the template be used sparingly. Sławomir Biały (talk) 12:35, 18 March 2015 (UTC)

The immediate thing to do is to have the thing fixed. A recommendation is MOS (while I support it) will only have a small and long term effect. There are potentially thousands (choose your prefix) of places where it is used today. Village pump? YohanN7 (talk) 12:55, 18 March 2015 (UTC)

 Fixed. Missing style in Mobile.css. -- [[User:Edokter]] {{talk}} 13:11, 18 March 2015 (UTC)

Did you see how easy and quick that was Do you actually mean this is fixed globally, or on your mobile? Your user profile indicates you actually can fix things like this... YohanN7 (talk) 13:58, 18 March 2015 (UTC)

It is fixed for anyone here on English Wikipedia. This edit fixed it. -- [[User:Edokter]] {{talk}} 16:24, 18 March 2015 (UTC)

Kernel function for solving integral equation of surface radiation exchanges

What should be done with Kernel function for solving integral equation of surface radiation exchanges? I did a bunch of obvious copy-editing, and I hesitate to attempt to write a lead section. If the article ought to exist, a proper lead section should be added. Michael Hardy (talk) 19:42, 18 March 2015 (UTC)

Serpentine curve

The article titled Serpentine curve is very short. There must be immensely more one can say about this topic. It is about curves whose equation is

$y={\frac {abx}{x^{2}+a^{2}}}.$

Michael Hardy (talk) 23:43, 18 March 2015 (UTC)

Addition has been nominated as a featured article

After passing its good article nomination a few weeks ago, I have nominated addition for featured article status. If it goes well, I would like to go through and improve some more of our Top Importance Good Articles and nominate them as featured articles, one at a time. If anyone is interested in helping out, let me know, especially since I have never tried a FA nomination before.Brirush (talk) 17:41, 25 March 2015 (UTC)

I should mention that it may be helpful for members of the WikiProject Mathematics community to help with the review process (which needs input from many editors), pointing out deficiencies in the article or supporting its nomination. It may be difficult for editors in other areas to work through the abstract algebra sections, for instance.Brirush (talk) 21:44, 26 March 2015 (UTC)

Hilbert geometry

I've created a new disambiguation page titled Hilbert geometry, listing three items. Perhaps the present company can improve it. Michael Hardy (talk) 22:03, 26 March 2015 (UTC)

Robert Langlands

Dear mathematicians: There is an extensive article about this mathematician in today's Toronto Star. I have added a citation to his page, but more information from the article could be cited by someone whose math is less rusty. —Anne Delong (talk) 21:18, 27 March 2015 (UTC)

Migration of {{cite arxiv}}

The {{Cite arXiv}} template is being updated to be more consistent with other citation templates. This is likely to introduce some red error messages in existing Cite arXiv templates that use unsupported parameters or that should be converted to {{Cite journal}}. Please see this discussion. – Jonesey95 (talk) 15:01, 31 March 2015 (UTC)

Apr 2015

Should we delete Hamilton Mathematics Institute?

You can now opine at Wikipedia:Articles_for_deletion/Hamilton_Mathematics_Institute. Michael Hardy (talk) 04:51, 1 April 2015 (UTC)

Draft:Sabir Gusein-Zade

Hello. I wrote Draft:Sabir Gusein-Zade and it has been rejected twice. If someone here would like to help me to improve it so that it can be accepted I would be really grateful. Sorry about my bad English (it's not my native tongue you know...), I won't try to create articles again, but it will be sad to me if my work there (albeit modest) be deleted after the six months deadline... By the way, it seems that pages marked as "Draft:" are not shown by Google or Wikipedia searches in standard mode, making it difficult for other interested people to find them and maybe help to improve the drafts. Sincerely, --Rodrigo 189.6.212.77 (talk) 05:00, 2 April 2015 (UTC)

Suggest you use this link as a reference and mention his being editor-in-chief of MMJ. He clearly passes WP:PROF but this is not immediately apparent from the draft. —David Eppstein (talk) 05:24, 2 April 2015 (UTC)

Thank you for the suggestion and the link! I've just made an addition to the draft http://en.wikipedia.org/w/index.php?title=Draft%3ASabir_Gusein-Zade&diff=654669582&oldid=654592460 --Rodrigo 189.6.193.44 (talk) 18:51, 2 April 2015 (UTC)

Current activity page

What's going on with the Current activity page today? Its format is changed and most of it is blank. Michael Hardy (talk) 16:44, 3 April 2015 (UTC)

See User talk:Jitse's bot. Apparently the bot is feeling under the weather. It cleared out both this page and Wikipedia:Pages needing attention/Mathematics/Lists‎. —David Eppstein (talk) 17:16, 3 April 2015 (UTC)

Lancaster Edit-a-thon

Hi all; I'd like to let you know there will be a mathematical Wikipedia edit-a-thon this Wednesday at 3:30-6pm (UK time), in Lancaster University during a mathematics conference, as part of the 150th anniversary celebrations of the London Mathematical Society. The event page is here:

Wikipedia:WikiProject Mathematics/Lancaster University Edit-a-thon 8 April 2015

So feel free to join in online, and/or keep an eye on that page for any relevant activity. Cheers! Mark M (talk) 19:15, 6 April 2015 (UTC)

Steiner generation of a conic

Please could some one check the discussion on Steiner's theorem. User Wcherowi changed the sence of Steiner's thorem twice in such a way that it does not comply with Steiner's "Vorlesungen,...., Teil 2, p.96". Wcherowi's Steiner theorem is not the base of what he calls " sometimes referred to as Steiner's definition of conics or the projective generation of conics". Steiner (!) did proof the generation: see his lecture "Jacob Steiner’s Vorlesungen über synthetische Geometrie, B. G. Teubner, Leipzig 1867 (bei Google Books: [9]), 2. Teil, p. 96 ". Wcherowi changed the reference to Steiner's Vorlesungen such that it is wrong.--Ag2gaeh (talk) 08:01, 9 April 2015 (UTC)

The addition to this citation was accidentally omitted when I reverted. I have now fixed the citation. Comments on the above mentioned discussion are welcome. Bill Cherowitzo (talk) 16:22, 9 April 2015 (UTC)

Article "Montgomery reduction": Change its presentation to "Montgomery multiplication"

Hello Wikipedia Mathematics community,

I would like to propose a change to the article Montgomery reduction. The article is about a certain method for fast modular multiplication invented by the mathematician Peter L. Montgomery.

I'm a very newly registered user here on Wikipedia. (See my user page for a brief self-introduction.) I only learned of the subject of Montgomery multiplication via the Wikipedia article, and I am not an expert in the field. However, having now studied the subject for a few weeks I think I now understand the subject reasonably well, and I think I see a few ways to improve the article.

However, even if I now think I understand the subject reasonably well, I still preferred to seek discussion before I make edits, not only because I am completely new on Wikipedia, but also because I am new to the Montgomery multiplication subject. I.e., what I seek is the input of people who have contributed to the article and who are more familiar with the subject than I am. (For example, it may be that I am unfamiliar with the terminology or label under which the subject is classified in certain fields such as cryptology.) About 2 weeks ago I already posted on the article's talk page, but no one responded there, which is why in my attempt to seek discussion I am now posting this here.

In this posting, I would like to address the following set of very related problems with the article Montgomery reduction:

Properly speaking, the "Montgomery reduction" in the title of the WP article is in fact only a subroutine used internally inside the fast modular multiplication method invented by Montgomery. (In his 1985 paper, Montgomery used the desgination REDC() for this reduction subroutine.) Montgomery's fast modular multiplication method as a whole is properly called Montgomery multiplication. Moreover, this REDC() subroutine (= the algorithm performing "Montgomery reduction") is a subroutine that is specific to Montgomery multiplication, i.e. it is not a general-purpose algorithm that can be taken out of Montgomery multiplication and applied outside of it.

In the bulk of the text, the WP article actually in effect explains the complete Montgomery multiplication, and not only the REDC() subroutine for the Reduction step. (That the article explains the complete Montgomery multiplication is of course very logical, since it would be hard to explain the Reduction subroutine without explaining also the complete Montgomery multiplication.)

However, looking at the title, the lead section, and the section "Formal statement" in the beginning, the WP article seems to be presented as a description of "Montgomery REDUCTION" only.

I think this is a case of naming something for one of its parts.

(Note also that (at present) there does not exist a separate WP article titled "Montgomery multiplication".)

A very related problem with the article is the confusion between the following terms:

• Montgomery algorithm;
• The REDC() function (or algorithm);
• Montgomery step;
• Montgomery multiplication.

This terminology problem is IMO very much related to the improper "pars pro toto" title. The problem is a lack of clear distinguishing between terms and hierarchical algorithm elements in the beginning of the article (and in its whole presentation which includes its title). In my view, a reader new to the subject is from the beginning led to misunderstanding of terms and into confusion about what are the different algorithms and how they fit together. (At least, it caused me some confusion on first reading.)

The measure I would like to propose, to solve all these related problems in one go, is to change the presentation of the article from "Montgomery reduction" to "Montgomery multiplication".

This would involve the following:

• Change the title to "Montgomery multiplication" (or to something similar like "Montgomery's method for fast modular multiplication").

• Rewrite the lead section, to clearly disinguish the terms mentioned above (including mentioning there explicitly that the REDC() reduction function is a subroutine inside Montgomery multiplication, and including mentioning that "Montgomery algorithm" is ambiguous and can stand for either the REDC() algorithm or for a complete Montgomery multiplication step), so that all these terms are briefly identified and distingished right from the start. (This would also IMO make clear formulation of the bulk of the article text much easier.)

• Inside the article, rename the section "Formal statement" (which is about the REDC() reduction function) to something like: "Formal statement of the REDC() Reduction function".

I think that ideally the change would probably include also a small amount of rearranging/reordering of the structure of the article. E.g., move the sections "Formal statement" and "Description of Algorithm" into a section that deals with the the REDC() subroutine. Note that all the Examples in the article already are about Montgomery multiplication as a whole, and not about only the Reduction specifically. The section "Rationale" also in effect already explains Montgomery multiplication as a whole, and seems to me to need only very small editing work to adapt if the article presentation would be changed to Montgomery multiplication as a whole.

The Wikipedian Gronk Oz made the suggestion that it would be also a possibility, instead of changing the Montgomery reduction article, to add a separate new article titled "Montgomery multiplication". I would also like to invite your views on this idea. Questions: Does the subject merit two different articles? Was the intention of the creators of the existing article to discuss the Reduction exclusively, or to explain Montgomery multiplication as a whole (and if so why did they title it "Reduction" and not "Multiplication")?

Another thing I would welcome comments on is the following: This is only my speculation, but I could imagine that it could be possible that in some circles (maybe cryptology?), Montgomery's method for fast modular multiplication might conceivably be generally referred to under the label "Montgomery Reduction", same as many other things are commonly referred to under "pars pro toto" names. This might be a reason to consider keeping the the title "Montgomery reduction" intact. However, I am new to the subject and I have no knowledge of circles that use the "pars pro toto" label of "Montgomery reduction" when talking about "Montgomery multiplication". I invite people who have knowledge of circles that use this "pars pro toto" naming for this subject to speak up and comment.

There are no doubt many more kinds of improvement that could be made to this article. However in order to keep things focused, with this posting I seek discussion at first only on this specific issue.

Also, what I would like to discuss at this point is at first only the question of whether the change (or small package of changes) I am proposing is sensible or desirable. I.e. to reach a consensus decision on whether it would be good if the presentation of the Montgomery reduction article is changed to "Montgomery multiplication", leaving the bulk of the article text (including all Examples) intact. Addressing how exactly to implement this change (and when and by whom, etc.) seems then to me a later step.

I would like to acknowledge W.carter from the Teahouse, for pointing me to the Mathematics Project talk page, and Gronk Oz for enthusing and helpful discussion. (Any mistakes in the above are my own.)

With best regards, --MRaccoon (talk) 14:11, 7 April 2015 (UTC)

I'm no expert either, but I know someone who has thought about Montgomery multiplication before, and I've always heard him refer to "Montgomery multiplies" or "Montgomery multiplication". I doubt that there is enough material for two separate articles, so I think that the article ought to be moved. You should do this yourself, and right now! The general principle here is be bold. You should feel free to reshape the article however you please (as long as you are honestly trying to make it better, something which doesn't seem to be a problem in your case). It sounds like you know enough about the subject to write a much better article. Ozob (talk) 14:25, 7 April 2015 (UTC)

@Ozob: Hello Ozob, thank you for your comment, which is much appreciated. Thanks for taking the time to comment, and for commenting so quickly. Your opinion is pretty decided and definite, which is a great encouragement.

I am impressed by the discussions between you and MarcusMaximus on your user talk page, about differentials and coordinate systems (of which much is unfortunately over my head; I can just understand its significance, and I have always regarded both subjects as pretty fundamental). Given that, your information that you know one person who refers to Montgomery's invention as "Montgomery multiplication" and not "Montgomery reduction" sounds to me like a significant data point.

I had seen the BOLD, and I completely understand how it is imporant in the Wikipedia mechanism; but opinions seem to differ as to the degree to which it is allowed for new users to actually be BOLD. Plus I have (had) initially a little hesitation caused by my own "ethical" concern that one shouldn't interfere in stuff that others have created, no matter how loudly they say that it is allowed. However, with your comment you have now pretty much changed me over to an expectation that everything will probably be OK and that I will probably go ahead and make the changes I proposed.

As regards "right now", that seems a separate question. I'm a bit on the "slow and deliberate" side there. I am in no particular hurry myself, so I am feeling rather that it woudn't hurt me to wait a few more days before I post a "Move request". That would allow more people to comment here on the proposal. I would like to repeat my invitation to anyone who has contributed to writing the article to speak up and comment; and in particular I would urgently like to hear from anyone who has information that the subject is in some circles commonly referred to under the name "Montgomery REDUCTION" (and not "Montgomery multiplication").

Thanks to you and to all, and with best regards, --MRaccoon (talk) 19:43, 7 April 2015 (UTC)

I agree with Ozob, that you are able to dramatically improve the article. Do not worry about interference with others stuff: In WP, nobody is owner of anything, and the best articles result of the interference between of many editors.

About the title, I have also heard about "Montgomery multiplication", never about "Montgomery reduction". As changing a title may be more difficult for a new user, I was intended to change the title myself, leaving to you to adapt the content. However, looking on the articles linking to it (button "what links here" on the left), it seems that "Montgomery modular multiplication" would be a better title. Therefore, I'll move the article to this title, leaving a redirect, and also create a redirect "Montgomery multiplication". If you do not agree to include "modular" in the title, it would not be difficult to move again. In any case, you seem the best to adapt the content of the article. D.Lazard (talk) 21:42, 7 April 2015 (UTC)

@D.Lazard: Hello D.Lazard, many thanks for your comment, and for your encouragement. Thanks for your feedback on the naming of the subject. I see that you have now changed the title to "Montgomery modular multiplication".

I think it is a good idea to include the word "modular" in the title. I believe that prevention of misinterpretation up front is one of the main methods for achieving clarity of exposition in a text, and that it is better to be too verbose than to risk misinterpretation. It seems to me that it is good very early on to explicitly state the "obvious" fact that the subject falls under modular arithmetic, because for many readers it may not be obvious, and stating it may prevent many misinterpretations by readers unfamiliar with the subject. It also makes the subject easier to explain and the bulk of the text easier to formulate, because you have already eliminated possible misinterpretations up front and do not need to deal with those possible misinterpretations much more in the bulk of the text. So as for me I quite agree with the fuller title including the word "modular", and I am very happy with the title change you made. I agree that adding the redirect from "Montgomery multiplication" is important (I checked that both redirects are working correctly).

I now intend to wait for a day or two to see if there are other comments on the title change. Thereafter I will then go ahead and carry out the edits in the article text that I proposed. (Or possibly I may begin putting in some few preliminary edits in the lead section sooner.) Many thanks for your encouragements and support, and With best regards, --MRaccoon (talk) 10:39, 8 April 2015 (UTC)

PS (off topic): No one owns anything, I knew that of course, but it is indeed a fact that bears repeating (for me). I had previously only been used to company wikis (containing internal company information like internal software documentation), where in effect every page had an "owner" in the sense of one person who is responsible for that page. There, if you wanted to change something in an existing page, the unwritten but quite definite rule was that you always discuss it first with the person responsible for the page.

Wikipedia demonstrates that it is (apparently) possible to run a wiki without the "ownership responsibility" mechanism, and exclusively on the basis of the mechanism of social control. I am finding that a quite interesting and curious phenomenon of sociology. It tells you something interesting about how people work (one gets the impression that with humans, social control is more influential than anything else). Philosophical questions related to it fairly leap out at me (e.g. implications for politics). Being located politically on the side of "classical liberalism" and very far away from socialism, I'm finding a world lacking the "ownership responsibility" mechanism definitely very curious (to put it very mildly). The "no one owns anything" is taking me a minute to get used to (e.g. also the idea that what I write is then not my responsibility any more and is "common property" and can in principle freely be hacked and mashed up by anyone), but as regards how it works for practical matters here on Wikipedia I think that I got it now. Sorry for the off-topic post. --MRaccoon (talk) 14:19, 8 April 2015 (UTC)

Well, as long as we're off topic...

Social pressure is not the exclusive means of control on Wikipedia. If it were, the project would fall apart. If you want to further your study of Wikipedian sociology, see Wikipedia:Vandalism, Wikipedia:Disruptive editing, Wikipedia:Blocking policy, and Wikipedia:Arbitration Committee.

I think of Wikipedia as a charitable endeavor. Legal ownership of Wikipedia rests with the Wikipedia:Wikimedia Foundation (WMF), and I see my work here as a kind of charitable donation (the actual legalities are more complicated: I retain ownership of my words and grant WMF a license to use them. However the spirit is that of a charitable contribution). Once I've charitably contributed my words, I lose control over them. WMF takes my charitable contributions of words and distributes it to needy minds across the globe. It also allows others to make their own charitable contributions on top of mine. If I don't like the direction an article has taken, I'm free to make another charitable contribution. This perspective is, I believe, consistent with both classical liberalism and socialism. Ozob (talk) 04:17, 9 April 2015 (UTC)

Hello Ozob and all,

Ozob, thanks for your comment. I'm discovering that in my previous comment I may have used the term "social control" somewhat inaccurately. I'm pondering this some more. For this off-topic sociology subject, I'm considering creating a section on my talk page for it, and then replying further there (after I have given the subject some more thought).

On the Montgomery subject, while writing out a formulation of the whole thing for myself I'm discovering that I'm not completely clear myself yet about one or two small points of the mathematics of the thing. It may take me a few days more to get this clear to myself. After I arrive there, and in case I am not sure at that point how to integrate my new stuff into the article, I will then seek discussion again (here or on the article's talk page).

Thank you and with best regards --MRaccoon (talk) 09:29, 12 April 2015 (UTC)

Draft:Ricci soliton

This draft was prepared last October by Mbw314 (talk · contribs), who never submitted it for review and has not edited since. It qualified for speedy deletion under WP:CSD#G13 as an abandoned draft, but I have postponed that in case it is worth keeping, or can be developed. Comments welcome. JohnCD (talk) 16:35, 12 April 2015 (UTC)

I think it is worth keeping. It passes my BS and OR detectors (but I have no idea of what the thingies are). A Google search gives plenty of seemingly trustworthy hits. A couple of more references and an inline citation or two, and I think we have decent stub article. YohanN7 (talk) 17:50, 12 April 2015 (UTC)

This is an extremely important topic in global analysis. I'm surprised there is not already an article. Sławomir Biały (talk) 17:55, 12 April 2015 (UTC)

I concur with Sławomir, this is a quite notable topic. Ricci solitons are covered briefly in Ricci flow, but are deserving of their own article. Here is an example secondary review article on Ricci solitons. --Mark viking (talk) 18:59, 12 April 2015 (UTC)

Help checking accuracy of the statements in an article

Sorry guys, I don't know where to ask help from fellow mathematicians in wiki. Several users (including me) have disputed the statement in Eigenvalue perturbation and its proof. Can someone check it? Best, Taha (talk) 21:27, 16 April 2015 (UTC)

Wikipedia talk:Articles for creation/Poincaré Separation Theorem

Dear mathematics experts: here's an old AfC submission on a mathematical subject. Is this a notable topic, and should the page be kept and improved instead of being deleted as a stale draft?—Anne Delong (talk) 17:38, 13 April 2015 (UTC)

This looks notable to me. The theorem is discussed in many books on matrix mathematics and has an entry in the CRC Concise Encyclopedia of Mathematics, Second Edition. If it is notable enough for a published encyclopedia, it is notable enough for us. --Mark viking (talk) 18:06, 13 April 2015 (UTC)

Notable. It also appears in Horn and Johnson "Matrix analysis". Sławomir Biały (talk) 19:35, 13 April 2015 (UTC)

Thanks, Mark viking and Sławomir Biały. It's in mainspace now at Poincaré separation theorem.—Anne Delong (talk) 21:37, 16 April 2015 (UTC)

Missing list of new articles?

Wikipedia:WikiProject Mathematics/Current activity shows no new mathematics articles for the last three days, which seems quite unlikely. Jitse's bot, the one that updates current activity, seems to be running ok, but maybe there's some other link in the chain that's malfunctioning? —David Eppstein (talk) 01:40, 20 April 2015 (UTC)

I think you should talk with the user that owns the bot. He may have more knowledge in pinpointing the exact problem. Doorknob747 (talk) 15:20, 20 April 2015 (UTC)

The problem could be with Oleg's bot rather than with Jitse's bot. That would explain why other aspects of the page than the new articles list have continued to get updated. Michael Hardy (talk) 16:51, 20 April 2015 (UTC)

Yeah, it is mathbot who is not doing the job. I will take a look tonight (PST). Oleg Alexandrov (talk) 20:18, 20 April 2015 (UTC)

Mathbot should be back in business. I will double check again tomorrow. Oleg Alexandrov (talk) 04:47, 21 April 2015 (UTC)

Thanks! This listing is very helpful. —David Eppstein (talk) 06:38, 21 April 2015 (UTC)

The current activities page and its list of new articles depend on two people who run bots. Some day they will die and Civilization will collapse unless we have some crowd-sourced way of running those bots. Michael Hardy (talk) 15:22, 21 April 2015 (UTC)

That's good point indeed. I will be very happy if other people can help run mathbot, and I am pretty sure Jitse would feel the same about his bot. Mathbot's code is public, available at https://github.com/oleg-alexandrov/mathbot, and it lives on the toolsever. In both places there is functionality for shared ownership. The bigger stumbling block would be that mathbot is written in Perl, and most people (my present-day self included) would find Python more appropriate. Oleg Alexandrov (talk) 05:28, 22 April 2015 (UTC)

Requested move: total quotient ring -> total ring of fractions

If this is the stuff you find exciting, then the comments and the feedbacks are very welcome at Talk:Total quotient ring. -- Taku (talk) 22:11, 24 April 2015 (UTC)

Orphaned status of Poincaré separation theorem

So far the only article linking to Poincaré separation theorem is the List of things named after Henri Poincaré, where I added the link. Higher up on this page, you see several people vouching for the theorem's notability, and one saying it appears in many books. Would someone who knows the topic add some links? Michael Hardy (talk) 15:27, 21 April 2015 (UTC)

The theorem is a consequence of the variational characterization of eigenvalues. Looking at the text by Horn and Johnson, "Matrix analysis", this is sometimes known as the Courant-Fisher theorem (although we lack an article by that title). There is a related result due to Weyl (also discussed there) that is quite famous, to do with eigenvalues of the sum of two hermitian matrices. I wonder if we have an article about that theorem. Sławomir Biały (talk) 18:22, 21 April 2015 (UTC)

I don't know this material very well at all, but is there a connection between the Poincaré separation theorem and min-max theorem? They look pretty similar, and if they are closely enough connected this might provide a potential cross-link to remove the orphan tag. —David Eppstein (talk) 07:01, 24 April 2015 (UTC)

Poincaré separation theorem and Min-max theorem#Cauchy interlacing theorem both refer to the same theorem (just the orderings of the eigenvalues are reversed). It can be proven using the Courant-Fischer theorem. Cauchy stated the interlacing theorem for principal submatrices only. Poincaré proved the general case, but only one side of the inequalities. The first complete treatment is due to Courant. Best wishes, --Quartl (talk) 09:22, 28 April 2015 (UTC)

Confused about a book

Chapters of N.W. Johnson: Geometries and Transformations, (2015) are being cited in various wiki pages on groups. But it doesn't seem to be a published book. Is it some kind of samizdat or what? Some1Redirects4You (talk) 13:34, 20 April 2015 (UTC)

Probably of vandalism. Doorknob747 (talk) 15:21, 20 April 2015 (UTC)

No, this is probably continued bad sourcing of original research. I know Tomruen has used Johnson as a source in the past; is he still doing this or is it someone else this time? —David Eppstein (talk) 16:07, 20 April 2015 (UTC)

I have a preprint copy, but haven't added any references since last fall. Tom Ruen (talk) 19:00, 20 April 2015 (UTC)

Thanks. Someone else then, given the date of the reference. —David Eppstein (talk) 20:04, 20 April 2015 (UTC)

I can't be bothered to check every edit in https://en.wikipedia.org/w/index.php?title=Octahedral_symmetry&action=history but the last 50 edits (from Dec 2014) were basically by Tom Ruen. Did someone add the book prior to 2014 with a future date? Also, that article should probably be made easier to understand by newbies as it's a common symmetry group. Too much Coxeter-based jargon at the front, IMHO. Some1Redirects4You (talk) 16:35, 28 April 2015 (UTC)

May 2015

a flawed and clumsy definition

How, if at all, should one rephrase the definition quoted in this comment? Michael Hardy (talk) 14:57, 30 April 2015 (UTC)

As for me, this is a common illusion of non-mathematicians: to think that there are such mathematical notions as "variable", "discrete variable", "continuous variable". And therefore, an article with such title should not start with "in mathematics". Maybe "in elementary teaching of math" or something like that? Boris Tsirelson (talk) 17:45, 30 April 2015 (UTC)

(A bit off-topic, but not completely:) I was astonished to see that most non-mathematicians believe that such notions as "journal", "article", "professor" etc. exist among mathematical notions! Boris Tsirelson (talk) 17:48, 30 April 2015 (UTC)

On the other hand, we have an article "curve" with such phrase: "Various disciplines within mathematics have given the term different meanings depending on the area of study, so the precise meaning depends on context." Maybe something like that? Boris Tsirelson (talk) 19:10, 30 April 2015 (UTC)

Yes, but curves, even without full agreement on the precise definition, are an actual object of study. Does anyone study discrete and continuous variables, per se? I generally dislike articles that exist mostly to document jargon.

It's occasionally OK to have a short article that's mostly definition plus a couple of interesting facts about the objects meeting the definition; these won't ever be very good articles but they might sometimes be the best feasible solution. That's different from just observing some aspect of mathematical usage in practice and deciding to turn it into an article.

So, bottom line, I probably support redirecting to variable, unless someone can explain why not. --Trovatore (talk) 00:26, 1 May 2015 (UTC)

Presumably you mean variable (mathematics). In any case the topic of discrete (usually meaning integer-valued) vs continuous (real-valued) variables is an important one in optimization — see e.g. discrete optimization — in part because continuous variables allow methods like linear programming to be used but discrete variables are harder to handle. Searching Google scholar for "discrete variable" also finds very heavily cited works with this phrase in their title involving differential equations, and less-heavily but still well-cited works using this distinction in biostatistics. So I think it's a notable topic, but it needs to be rewritten to make clear that the distinction applies only to numeric variables. As for "documentation-of-jargon articles" that are in even stronger need of some sort of action: does anyone have a good idea what to do with of the form? —David Eppstein (talk) 01:01, 1 May 2015 (UTC)

Draft:Ricci soliton

Hi, this draft seems to be about a mathematical topic and I would greatly appreciate if anyone could provide feedback about whether the draft is suitable for Wikipedia. Thanks! Darylgolden^(talk) Ping when replying 13:51, 29 April 2015 (UTC)

Yes, it's a notable topic. Push it out to mainspace please. Sławomir Biały (talk) 17:28, 29 April 2015 (UTC)

 Done and it is now stubbily awaiting improvement at Ricci soliton. I've put it in Category:Riemannian geometry to start with. Arthur goes shopping (talk) 10:29, 2 May 2015 (UTC)

Draft:Convenient Analysis in infinite dimensions

Hello, mathematicians. Here's another of those old drafts about to be deleted. Anything worth keeping here? —Anne Delong (talk) 19:44, 21 April 2015 (UTC)

"Convenient vector spaces" gets about 200 hits on GScholar, including some secondary references, including books by Frolicher and Kock. I'd say the topic is notable. The article itself is fairly technical and likely written by one of the experts in the field. Unfortunately, that expert seems to have gotten discouraged by the rejection and left WP. The article could use more wikification and more non-Kreigl/Michor refs, but this is a matter of editing that is best done in mainspace. It's not a slam-dunk, but I think it would be good to bring it into mainspace. --Mark viking (talk) 20:04, 21 April 2015 (UTC)

And definitely not OR. Boris Tsirelson (talk) 20:14, 21 April 2015 (UTC)

Yes, I've heard of these. These have been studied extensively by Peter Michor and Andreas Kriegl (there is an AMS monograph here). I object slightly to the title. I think it should be titled convenient vector space. But otherwise this is good content that should be kept. Sławomir Biały (talk) 20:35, 21 April 2015 (UTC)

Definitely the title of the draft can't stay. What's an infinite dimension? --Trovatore (talk) 20:47, 21 April 2015 (UTC)

I changed the initial "A" in "Analysis" to a lower-case "a". Michael Hardy (talk) 04:42, 22 April 2015 (UTC)

Really? That bothered you worse than "infinite dimensions"? --Trovatore (talk) 04:51, 22 April 2015 (UTC)

It's not always a question of which bother me more. It might be a question of which one can be changed easily. Michael Hardy (talk) 23:17, 2 May 2015 (UTC)

The difficulty of changing it seems about the same to me. BTW I posted a related query on WP:RD/Language, which no one ventured to answer, which surprised me somewhat. See here — it's off-topic on this page, but I'd be interested in your thoughts on the subject, as I know you are also interested in language. --Trovatore (talk) 23:25, 2 May 2015 (UTC)

Please visit Draft talk:Convenient analysis in infinitely many dimensions. Boris Tsirelson (talk) 05:07, 22 April 2015 (UTC)

• Mark viking, Boris Tsirelson, Trovatore, Michael Hardy, it seem that everyone agrees that this is a notable topic. Before it goes live, I think it needs a less essay-like and more understandable lead section. I have written a suggested wording on the talk page, HERE. Let's continue the discussion there as Boris Tsirelson has suggested. —Anne Delong (talk) 11:05, 22 April 2015 (UTC)

Indeed, we should be thankful to Anne Delong; she is our only "mechanism" (sorry Anne) for saving valuable new articles in such cases. Boris Tsirelson (talk) 13:33, 22 April 2015 (UTC)

Well, you could cut out the middlewoman here, and use the search box below. To find drafts, type math-related keywords such as "mathematics", "integer" "vector"... well, you can think of some. All I ask is that if you find one that is of no use, and it has the pink notice that it's eligible for deletion under db-g13, just nominate it for deletion or let me know, but don't edit it - that removes the eligibility. I'll be glad to help with non-math-expert aspects of any you find. —Anne Delong (talk) 23:06, 22 April 2015 (UTC)

Tapering (mathematics)

Deletion of Tapering (mathematics) has been proposed. Is the article worth keeping? Michael Hardy (talk) 14:24, 4 May 2015 (UTC)

The article is indeed rather unclear in its current form, but tapering is certainly an important concept. However, it is covered in Window function. FireflySixtySeven (talk) 22:33, 4 May 2015 (UTC)

Tapering is well-known operation in solid modeling in computer graphics. It is a shape deformation operation, like bending or twisting [10], that alters the mesh representing solid, often deforming part of the shape down into a conical or prism-like section.. It is more akin to the tapering one does in a machine shop than tapers used in, for instance, signal processing. Definitely has nothing to do with exponential decay. I'm going to deprod, but a move to Tapering (computer graphics) may be warranted. --Mark viking (talk) 23:37, 4 May 2015 (UTC)

Watch out for crank user 108.242.169.13

108.242.169.13 (talk · contribs) came to my attention because of these edits to Talk:Van_der_Waerden_number; the author claims to have solved the (open) problem of the minimal n such that any k-coloring of the integers 1…n must contain a monochromatic k-term arithmetic progression. Since Wikipedia policy restricts talk page discussions to discussions about the article, this revelation was removed, once by mfb (talk · contribs) and once by myself. I also posted a relevant admonishment on 108.242.169.13's talk page. He is irate, and perhaps a response is in order. I tried to write one, but it came out unacceptably rude so I am not going to post it. The best response may be no response at all, just remove his material without engaging him.

The user claims to be Bill Bouris, a high school and community-college teacher of mathematics; his web site http://www.oddperfectnumbers.com/ is filled with similar crankery, boasting many unintelligible solutions of longstanding open problems. For example, he claims to have proved that there are no odd perfect numbers. He has also begun discussions on similar crankery at at least four other pages, which you can see in his user contributions page. mfb (talk · contribs) has reverted most of it, except at Talk:Langford_pairing, where David Eppstein (talk · contribs) opted to bring it back. —Mark Dominus (talk) 23:03, 6 May 2015 (UTC)

He has also appeared as 99.135.160.136 (talk · contribs). —Mark Dominus (talk) 23:06, 6 May 2015 (UTC)

We can remove again from the Langford pairing talk if you prefer. I brought it back only because it was a removal of talk page content without an adequate edit-summary explanation for what was being removed and why, if I remember correctly. I agree that it's crankery and is unlikely to be usable to improve the encyclopedia. —David Eppstein (talk) 23:21, 6 May 2015 (UTC)

I have no preference either way, and I did not mean to criticize your action, only to report on the current status. —Mark Dominus (talk) 23:30, 6 May 2015 (UTC)

Platonic solid - Classification

Please offer a view at Platonic solid#Classification. The issue concerns whether the existence of the five Platonic solids can be answered easily by an explicit construction, or cannot. Johnuniq (talk) 06:53, 5 May 2015 (UTC)

As for me, yes, it can (easily or not - this may be controversial). Boris Tsirelson (talk) 10:29, 5 May 2015 (UTC)

Agreed, "cannot" makes no sense here. --JBL (talk) 15:31, 5 May 2015 (UTC)

Likewise. I have corrected the statement. —Mark Dominus (talk) 15:00, 7 May 2015 (UTC)

PigTex

Is this just my lack of understanding of Tex?

Below, the "A" and "B" are supposed to be absent.

${\begin{aligned}A[G_{m}^{i},G_{n}^{j}]&={C^{ij}}_{k}G_{m+n}^{k}+\delta _{m}^{ij}\delta _{m+n,0}C\\B[C,G_{m}^{i}]&=0.\end{aligned}}$

Remove "A" to obtain

${\begin{aligned}[G_{m}^{i},G_{n}^{j}]&={C^{ij}}_{k}G_{m+n}^{k}+\delta _{m}^{ij}\delta _{m+n,0}C\\B[C,G_{m}^{i}]&=0.\end{aligned}}$

Remove "B" (but keep "A"), then (Removed crashing Tex to save eyes)

?
(Using PNG) YohanN7 (talk) 13:52, 7 May 2015 (UTC) Interestingly, MathML gives a more informative error message:

Failed to parse (Conversion error. Server ("http://mathoid.svc.eqiad.wmnet:10042") reported: "Error:["TeX parse error: Bracket argument to \\\\ must be a dimension"]"): {\begin{aligned}A[G_{m}^{i},G_{n}^{j}]&={C^{{ij}}}_{k}G_{{m+n}}^{k}+\delta _{m}^{{ij}}\delta _{{m+n,0}}C\\[C,G_{m}^{i}]&=0.\end{aligned}}

This is different from what PNG reports. YohanN7 (talk) 13:59, 7 May 2015 (UTC)

Solution?

Insert some air in the form of a pair of braces {}, "A" -> "{}", "B" -> "{}":

${\begin{aligned}{}[G_{m}^{i},G_{n}^{j}]&={C^{ij}}_{k}G_{m+n}^{k}+\delta _{m}^{ij}\delta _{m+n,0}C\\{}[C,G_{m}^{i}]&=0.\end{aligned}}$

Both pairs of braces are necessary. I guess this is due to my lack of understanding of Tex. The square brackets are usually used to pass additional arguments to an "environment", right? YohanN7 (talk) 14:08, 7 May 2015 (UTC)

Presumably the problem is with how the parser treats the \begin{align}. It looks to me like it is expecting an optional argument (which would be enclosed in square brackets). I don't think align accepts any arguments in LaTeX, so this must be something specific to our implementation. Sławomir Biały (talk) 14:41, 7 May 2015 (UTC)

A bracket that follows immediately a Latex command is generally considered as an optional parameter to this command, even if this command does not accept any optional parameter. In the case of "\begin", which does not has any optional argument, this optional argument is simply ignored (it is possible that some parsers consider the [ as a part of the text, but this is clearly not the case, here). In the case of "\\", the optional argument, if present, indicates the size of the vertical space. Therefore, the error signal is correct, as well as the suggested correction. D.Lazard (talk) 15:24, 7 May 2015 (UTC)

Thanks. YohanN7 (talk) 15:44, 7 May 2015 (UTC)

But if the command has no optional parameters, latex interprets brackets as ordinary brackets. The above commands all work as intended in ordinary latex. This is not what appears to be happening here. Sławomir Biały (talk) 16:30, 7 May 2015 (UTC)

Articles by Gisling

I would like to solicit opinions on how to handle the numerous articles by Gisling which consist largely of Maple 16 calculations and graphs. On his talk page several editors have raised concerns about these articles. In some cases, such as at Eckhaus equation, an editor went over the article, corrected it, and produced something respectable. In other cases, such as at Fujita-Storm equation, the concerns were not addressed. I started a discussion at Wikipedia:Articles for deletion/Bogoyavlenski-Konoplechenko equation asking to delete an article (and probably some related articles) on the flimsy grounds of WP:TNT in cases where I can't determine if even the subject of the article is accurately described (as it was not at Eckhaus equation - even the definition of this equation was erroneous.) I gutted several articles last night, but stopped short of going over all of them as I expected some resistance (which did occur this morning.) Note that Gisling has also contributed a large amount of quality material on the history of Chinese mathematics and other topics. --Sammy1339 (talk) 16:01, 9 May 2015 (UTC)

• • Majority of nonlinear differential equation and special function articles are sourced from US Government source:

United States Government: National Institude of Standards and Technolgy, Handbook of Mathematical Functions, Cambridge University Press 2010 printed edtion, 950 pages.( I bought this printed book)

there is also a web edition

US Government NIST Handbook of Mathematical Functions, full of color diagrams of various mathematical functions

It is a common practice in mathematics to plot graphs using either Matlab,Mathematica or Maple, for instance the graphs in Mathworld is generated wityMathematica, if you don't know how to make graphs using one of these, you have poor qualification , you are not qualified to edit any mathematic articles on wikipedia --Gisling (talk) 18:09, 9 May 2015 (UTC)

I don't think anyone objects to a few carefully selected plots that illustrate things well, but we shouldn't add plots just for their own sake. This is especially true of animations, which should be selected very carefully (see WP:IUP#ANIM) because of their generally larger file size, the inability to print or display on different media, as well as the fact that most readers find animations distracting. None of the animations in question seem to be good illustrations suited for the articles that they inhabit. Some samples are the galleries at: Discrete_q-Hermite_polynomials, q-Charlier_polynomials, Little_q-Laguerre_polynomials, q-Hahn_polynomials, Discrete q-Hermite polynomials, Continuous q-Jacobi polynomials, Continuous q-Laguerre polynomials, Affine q-Krawtchouk polynomials, Little q-Jacobi polynomials, dual q-Hahn polynomials, Al-Salam–Chihara polynomials, q-Racah polynomials. Even the stills at Coshc_function show poor judgement in the scale of the coordinate plane. (Who the hell plots a hyperbolic function over a domain like [-10,10]??) Clearly, your own advice is relevant: "if you don't know how to make graphs using one of these, you have poor qualification , you are not qualified to edit any mathematic articles on wikipedia". So, in short, I agree with the original poster that these galleries are a problem and many of them (including all of the animations) should be removed entirely per our image use guidelines.

Also, there is 唐戈 (talk · contribs · deleted contribs · logs · filter log · block user · block log), who seems to be stalking this issue and reverting any attempt to remove the galleries, otherwise defending Gisling's contributions at AfD, and inserting similar lists of unreferenced, poorly-formatted formulas into articles. I strongly get the impression that this is a sockpuppet or meatpuppet. Sławomir Biały (talk) 19:30, 9 May 2015 (UTC)

This talk page interaction is pretty discouraging, though I guess the final outcome was right. I agree that the animations I've seen on the pages linked in this discussion are useless. --JBL (talk) 21:45, 9 May 2015 (UTC)

• • Comment" I don't think this gentleman [11] is qualified to judge animations, because he never did one. Don't listen to what he talk, see what he did: he contributed only very simple 2D graphs in wikicommons, I don't think he has the ability to make 3D graphs in complex space, let alone animation.

Why animation ? When you have a function with more then 3 variables, the simplest way to visualize is make one parameter changes, then make animation plots. Apparently, this gentleman never makes a single graph with more than three variable

Any comparision ?? [12]

--Gisling (talk) 00:00, 10 May 2015 (UTC).

There are several fallacies here that need pointing out. First of all, the ability to create animations is not necessary to judge their suitability for an article. Secondly, as I have said, Wikipedia articles generally use animations very sparingly. So as a rule, I generally do not upload animations. But, thirdly, your entire methodology is flawed. I have uploaded animations, of a substantially higher quality than any of yours by the way. (I think the link you kindly provided above to your long list of bad, jerky, animations, with poorly selected aspect ratio, coloring, and mesh underscores this point. Any mathematical content of conceivable encyclopedic value in these animations is lost just from the sheer ugliness of this animatory effluent.) Sławomir Biały (talk) 01:07, 10 May 2015 (UTC)

Incidentally: the user whose username consists of two characters has been blocked indefinitely while Gisling has been blocked for three days for sock puppetry. --JBL (talk) 01:34, 10 May 2015 (UTC)

The quality of the TeX code at Fujita–Storm equation is still deficient, but far better than it was originally. If Gisling would improve his or her TeX skills, that would be a step in the right direction. For example:

${\sqrt {(}}x^{2}+5*x+15)$

should be changed to

${\sqrt {x^{2}+5x+15}}$

etc. Michael Hardy (talk) 21:30, 12 May 2015 (UTC)

Pearcey Integral graphs

US Government National Institude of Standard and Technology:NIST Handbook of Mathematica Functions has nice graphs of Pearcey Integral

http://dlmf.nist.gov/36.3

Can some one who claimed to be "Mathematica expert" provides similar graphs ?, Othewise, remove "Mathematica expert" claim please--Gisling (talk) 22:59, 9 May 2015 (UTC).

Is there some point to this question, or is it just trolling? --JBL (talk) 23:24, 9 May 2015 (UTC)

Aren't these images public domain anyway, if they are published by the US Government? Why reinvent the wheel? Sławomir Biały (talk) 23:48, 9 May 2015 (UTC)

If the federal government is the author of the work, as would be the case if the work were made for hire by its employees while on the job, then it is not subject to copyright. But the fact that the federal government publishes it, i.e. distributes it to the public, is not exactly the same thing. The federal government can buy a copyright or acquire it by bequest or donation, etc., and publish the work, and it's subject to copyright. Michael Hardy (talk) 21:07, 12 May 2015 (UTC)

Yes, I see http://dlmf.nist.gov/about/notices does not allow commercial re-use. Sławomir Biały (talk) 21:48, 12 May 2015 (UTC)

• Not that simple, you need to explain how that graph is obtained, I cannot just copy it and paste it to wikicommons, without knowing why and how. Honestly, I don't know how these plots were obtained(I never claimed myself as Maple expert), may be you can, Mathematica expert ? How about give it a try please, it is not that simple--Gisling (talk) 00:09, 10 May 2015 (UTC).

I am willing to make suggestions if you actually show a genuine interest, but I'm not getting that feeling from the interactions with you thus far. Instead, you have described me in the above thread as a "hooligan", in the AfD as "bloody ignorant", and this very thread seems like trolling in an overt attempt to bait me. (Why you have chosen to single me out, I do not know.) If you are genuinely interested in working it out, please post a comment over at the reference desk (this is not the right forum for such questions), including any details you think might be relevant to the computation, and I'll gladly see what I can do. Sławomir Biały (talk) 00:50, 10 May 2015 (UTC)

Inline Latex again

${\mathcal {}}_{P}l$e${}^{a}\mathbf {s}$e s${}_{e}{}^{e}$ Talk:Spectral theorem. YohanN7 (talk) 23:09, 14 May 2015 (UTC)

I would have expected an objective answer and/or discussion on the article's talk page, as you were the one who told me to put that issue there…--*thing goes (talk) 23:26, 14 May 2015 (UTC)

There is the place to talk, not here or on my talk page. This here is an invitation to others to join in there because it isn't a dispute between you and me. YohanN7 (talk) 23:37, 14 May 2015 (UTC)

How can I join?

Please join me here. :) — Preceding unsigned comment added by Sophie Concepcion (talk • contribs) 11:36, 16 May 2015 (UTC)

Stella (software)

Can anyone more familiar with our guidelines on software determine if Stella (software) is notable? I can't escape the feeling that Wikipedia is being used as a marketing platform here. Sławomir Biały (talk) 13:10, 8 May 2015 (UTC)

.

I personally not familiar with Stella, but I know that scientists use Stelle to model natural enviroments

[http://www.uvm.edu/~jphoffma/GSA/Generic.pdf Dr. E. Alan Cassell,Short Course System Dynamics Modeling of Natural Environments: An Introduction to STELLA Sunday 11 March 2001 Geological Society of America Northeastern Section 36th Annual Meeting, So. Burlington, VT.]

• Pharmacokinetic modelling using Stella on the Apple Macintosh

• [ https://books.google.ca/books?id=e6PaBwAAQBAJ&pg=PA41&dq=Stella+modelling&hl=en&sa=X&ei=i1xOVYmEJY6fyATKuoDQCQ&ved=0CFMQ6AEwCA#v=onepage&q=Stella%20modelling&f=false simulation of economic]

• Simulation in social sciences

• I don't go by "feeling" to judge an article. It is extremely irresponsible hooliganism--Gisling (talk) 19:22, 9 May 2015 (UTC).

Note to Gisling: the STELLA simulation software that you mention is not the same as the Stella polyhedron modeling software discussed in Stella (software). I agree that the STELLA simulation software is likely notable--at least I have seen a number of reviews, and as you note, books. But other than passing mentions at Geometry Junkyard and in a book, I've been unable to find secondary reviews of the Stella polyhedron software that are reliable. Probably not notable. --Mark viking (talk) 19:34, 9 May 2015 (UTC)

Well, given that the best you could come up with is a completely different software, I take it you agree that this is non-notable WP:ADVERTISING. And, fwiw, compliance with WP:NOT is not "hooliganism". That's just a baseless personal attack, which looks particularly silly given that you apparently failed to understand what the article was about. Sławomir Biały (talk) 21:06, 9 May 2015 (UTC)

I have Stella software, and I've used it for making many of the polyhedron images on Wikipedia. But on notability standards, I'm not in a position to offer an opinion. Tom Ruen (talk) 02:55, 13 May 2015 (UTC)

It is now at AfD: Wikipedia:Articles for deletion/Stella (software). Sławomir Biały (talk) 13:07, 16 May 2015 (UTC)

Actuary FAR

I have nominated Actuary for a featured article review here. Please join the discussion on whether this article meets featured article criteria. Articles are typically reviewed for two weeks. If substantial concerns are not addressed during the review period, the article will be moved to the Featured Article Removal Candidates list for a further period, where editors may declare "Keep" or "Delist" the article's featured status. The instructions for the review process are here. SandyGeorgia (Talk) 02:09, 17 May 2015 (UTC)

Floyd–Warshall algorithm

I could use some more eyes at Floyd–Warshall algorithm, please (see recent article history and talk page comments). —David Eppstein (talk) 23:08, 16 May 2015 (UTC)

Sigh. Still needs attention. --JBL (talk) 02:35, 17 May 2015 (UTC)

KasparBot

A bot is running amok and adding a template called 'Authority control' to the bottom of pages. It generates links that make little sense. See e.g. This version of Topological group (at the bottom). Is this legitimate? (If it is I'd say its legitimate bs, therefore bs, hence should not be here or anywhere.) YohanN7 (talk) 19:32, 16 May 2015 (UTC)

I mean, what is a link to National Diet Library doing there? whatever this is isn't much better. YohanN7 (talk) 19:52, 16 May 2015 (UTC)

Think of it as being like an interwiki link, except that instead of going to the German-language Wikipedia entry on the same topic it goes to the German National Library's entry on that topic. We've had these on biography for a while now, but this is the first I've seen of them being added to abstract topics. —David Eppstein (talk) 20:03, 16 May 2015 (UTC)

They sometimes link to pages in Japanese. Legitimate nonsense or not, it is nonsense. YohanN7 (talk) 20:12, 16 May 2015 (UTC)

What language would you expect a catalog entry from a Japanese national library to be in? Reading authority control might or might not help clarify what's going on here. —David Eppstein (talk) 20:35, 16 May 2015 (UTC)

Doesn't matter if there is an explanation buried somewhere. What is the purpose? How does this improve the articles? Has this diet library (as they call themselves) donated $1 000 000 to English Wikipedida? YohanN7 (talk) 20:51, 16 May 2015 (UTC)

You don't understand the purpose of a link from an article to library information about the same topic? This seems obvious, at least in the abstract. --JBL (talk) 21:01, 16 May 2015 (UTC)

How does these links help me? Do they offer a free course in Japanese? You are right I don't understand. If there are good places to link I link them (manually). YohanN7 (talk) 21:05, 16 May 2015 (UTC)

Possibly you should consider the possibility that some people speak English and Japanese, even if you are not among them. -JBL (talk) 21:12, 16 May 2015 (UTC)

That's no answer. How does it help me and the (few) others that don't speak Japanese and English (or Bemba)? YohanN7 (talk) 21:22, 16 May 2015 (UTC)

In exactly the same way that interwiki links to Japanese versions of articles don't help you. They're useful information for a subset of our readers that doesn't include you. —David Eppstein (talk) 21:38, 16 May 2015 (UTC)

Just to provide some background, naming authority files provide a standard naming ontology for library catalogs and are good for semantic web stuff, too. An example is the Integrated Authority File from the German National library. Working toward a standard ontology is a good thing for topic cross referencing and is one of Wikidata's objectives, IIRC. The question I have is: why are we linking to the National Diet Library of Japan naming authority, when the Library of Congress naming authority, called LCNAF, seems just as good and would be more immediately useful to English speakers? --Mark viking (talk) 22:12, 16 May 2015 (UTC)

I have no inside knowledge, but the {{authority control}} template is fairly agnostic about such choices, merely reporting what is available on the wikidata entry for the article. So my guess is either (1) someone took the effort to enter Japanese naming authority data on wikidata and nobody has done the same thing for LCNAF, or (2) someone took the effort to program the automatic transcription of Japanese authority control wikidata into our authority control template, and nobody has done the same thing for LCNAF. —David Eppstein (talk) 22:30, 16 May 2015 (UTC)

That makes sense, thank you. --Mark viking (talk) 00:23, 17 May 2015 (UTC)

Since this occupies a box of height at least three lines, it could at least spell out what it is about and where the links go. E.g. NDL → National Diet Library. It is also inconsistent. Sometimes it links to, not a library wiki-entry but to Integrated Authority File. Instead of saying "Authority control" it should spell out what the hell it is supposed to be. "Library catalog entry" or whatever. A parenthetical (in Japanese) might be appropriate when applicable.

When I first encountered this, I clicked the links and immediately took it for vandalism/some sort of unauthorized promotion. YohanN7 (talk) 09:03, 17 May 2015 (UTC)

As it is now it is just amateurish littering (yes, I am now aware that there are people around speaking Japanese—even German—thanks all for patiently explaining this to me). While we are at it, there is also the LIBRIS authority file. That would serve Swedish-speakers well. YohanN7 (talk) 09:03, 17 May 2015 (UTC)

"This metadata template links Wikipedia articles to various library catalogue systems. At the moment, it is used almost exclusively in biographical articles and on user pages." (Quoted from Template:Authority control.) Really? Boris Tsirelson (talk) 11:08, 17 May 2015 (UTC)

This is not true: It has been added to Graph theory‎, Real number‎, Integer‎, Number theory‎, Diophantine approximation, Division (mathematics)‎, Numeral system‎, Binomial‎, Number, Angle, Equation, Arithmetic, Logarithm (this is the list of the articles of my watchlist to which the article has been added yesterday or today). D.Lazard (talk) 12:32, 17 May 2015 (UTC)

I raised the issue at Template talk:Authority control. Sławomir Biały (talk) 13:53, 17 May 2015 (UTC)

The essay Wikipedia:Authority control has more information about this. It seems like authority control was first implemented on the German Wikipedia, and the template is now being propagated via the interwiki links. I don't know enough to say if this is a good idea. I think a legitimate concern is that, as far as I know, interwiki links are not very well validated. But that would seem to defeat the purpose of authority control. A more immediate concern though is that the template itself is very confusing to readers (as evidenced by the existence of this very thread). It is quite possible that a reader can see the template, click the link to the article Authority control, read that article, and still have no idea what the damn thing is about. This at least should be fixed, perhaps by replacing the link in the template to Wikipedia:Authority control instead, and improving that essay. Sławomir Biały (talk) 13:02, 17 May 2015 (UTC)

AfC submission

Care to offer insight into Draft:Topological Functioning Model? Thanks! FoCuSandLeArN (talk) 20:01, 19 May 2015 (UTC)

Full rank

My colleagues and I agree that the property of being "full rank" makes perfect sense and has a conventional definition for rectangular matrices. However, none of the books I have on hand give a definition. Can anyone produce a RS? (Refer: [13].) --JBL (talk) 00:50, 13 May 2015 (UTC)

The book by Gentle on Matrix Algebra, section 3.36, discusses the notion of full rank for non-rectangular matrices. --Mark viking (talk) 02:58, 13 May 2015 (UTC)

That book refers to a "full [hyphen omitted] rank matrix" rather than to a full-rank matrix. Punctuation was taught in elementary school when I was there; the reason why one should write about a "full-rank matrix", with a hyphen, and also say that a matrix "is of full rank", without a hyphen, is quite simple, and the presence or absence of the hyphen can effectively convey a lot of information in some cases (e.g. the difference between a "man-eating shark", which scares people away from beaches, and a "man eating shark", who is a customer in an exotic restaurant). I think people are still accustomed to seeing the traditional standard use of hyphens in magazines, newspapers, and books on subjects in which the non-technically-trained copy-editor is not afraid to say too much, although writers of advertising copy and package labeling do not use it. I think maybe it could still be saved, if an effort were made. Michael Hardy (talk) 17:52, 14 May 2015 (UTC)

@Mark viking :

• What do you mean by a "non-rectangular matrix"?
• Does that book anywhere give an explicit definition of "full rank" for matrices that are not square?

BTW, there's a pretty bad typo in equation (3.122) in that book. It says

$(xA)^{T}C(Ax)\,$

where it should say this:

$(Ax)^{T}C(Ax)\,$

Michael Hardy (talk) 18:11, 14 May 2015 (UTC)

• Ah sorry, that was a typo (or perhaps a thinko). I meant to say non-square.
• On page 77, last paragraph, the books says if the rank of a matrix is the same as its smaller dimension, then the matrix is of full rank. Then it goes on to note that "full row rank" and "full column rank" are typically used when discussing non-square matrices. No hyphens in any of these definitions in the book as far as I can tell. --Mark viking (talk) 20:02, 14 May 2015 (UTC)

Our article Rank (linear algebra) seems a little confused on whether a matrix having full rank is (a) both of full column rank and full row rank (and hence a square matrix), or (b) either of full column rank or full row rank (and hence can be non-square). I find the second repugnant – it seems like what would be used when someone is too lazy to use the term full column rank or full row rank as appropriate. What is the dominant use? (I already put in a note, but no-one of knowledge has chipped in.) —Quondum 00:41, 15 May 2015 (UTC)

Over a field, a square matrix is invertible if and only if it is full-rank (right?) So, I don't think "full-rank" is particularly useful for a square marrix. For a non-square matrix, a "full-rank", I think, has the usual meaning, meaning the rank (row rank) is the maximal possible; i.e., the matrix defines a surjection when it is viewed as a linear transformation. For example, to check the submersion theorem applies one checks if the Jacobian matrix has full-rank, meaning it is surjective; see for instance [14]. At least, this (full-rank = surjective) is how I use the term in my day life. -- Taku (talk) 19:41, 15 May 2015 (UTC)

I don't feel that just because in some instances another definition happens to be equivalent that one should consider one of them "not particularly useful". Your argument of being equivalent to being surjective is far more persuasive. (Your first argument would argue against using a new term for 'surjective', though!) In the context of matrices, one cannot call a matrix 'surjective' though: it is left-multiplication by that matrix which would be surjective, or right-multiplication my that matrix. So again, one is looking at calling it 'full row rank' or 'full column rank', with 'full rank' being only sensible where the two are equivalent (e.g. square matrices over a field). —Quondum 20:24, 15 May 2015 (UTC)

Full-rank ⇔ surjective is just not right. But I have never seen 'full row rank' or 'full column rank'. 'Full rank' is unambiguous, but it may be more common to call it 'maximal rank', at least in differential geometry (it is still referring to matrices). YohanN7 (talk) 23:00, 15 May 2015 (UTC)

The term 'maximal rank' makes much more sense than 'full rank' when this meaning is intended, and if it is more common, the article could be updated accordingly, subject to sourcing/dominance. —Quondum 01:04, 16 May 2015 (UTC)

Right or not, my point was using "full-rank" for "surjectivity" seems fairly common at lease in differential geometry. The reason I think is that it doesn't make sense to say whether a matrix is surjective or not; thus, "full-rank" becomes a shorthand for the linear transformation given as the left multiplication by the matrix being surjective (doesn't roll well on the tongue, does it?). For a square matrix, there is no need for the term "full-rank" (except in the pedagogical context) since "invertible matrix" is simpler and more precise. -- Taku (talk) 02:32, 16 May 2015 (UTC)

You need to be careful about the precise meaning: words used in mathematics are often used imprecisely, with a lot implied by context. For example, 'Jacobian matrix' may be used to refer to the matrix, but implied may be the mapping between tangent spaces that it represents, which implies 'left multiplication by'. This does not apply to matrices in general, where properties often are not referenced to the properties of the operators they might represent, but typically more directly in terms of the components of the matrix. So in matrices, my perception is that the rank seems to be mostly defined in terms of the dimension of the space spanned by the rows or columns, respectively. This is not the same thing as the dimension of the image of its left and right multiplication, or whether it is surjective, because these are determined by the dimension of the domain and the dimension of the codomain, which can be less or more respectively than the number of columns and rows. So the fit is really quite poor. —Quondum 03:19, 16 May 2015 (UTC)

There seems some confusion. By definition, I agree, the row/column rank is the dimension of the space spanned by rows/columns (they turn out to be the same number). But the rank of the matrix can be equally characterized by the dimension of the image of the linear transformation determined by a matrix. Via the use of a transpose, we only need to consider the case by the left multiplication. Then the rank of the matrix is the dimension of the image of the matrix viewed as a linear transformation. In other words, there might be some "a priori" distinction that can be made from matrix point of view and operator point of view, but the distinction is not too important to be concerned in practice. A case in point: one speaks of finite-rank operator (by the way, as Michael Hardy noted, the universe collapses if you forget hyphen here) even though it is not really a matrix. Taku (talk) 14:10, 17 May 2015 (UTC)

You seem to be missing what I'm saying. The rank of a vector space can be less than the dimension of its representation (it is equal to the size of the basis, and hence the rank of a map can be less than the rank of the matrix chosen to represent it). When defining the rank of a matrix, Bourbaki explicitly uses vector spaces of dimension equal to the dimensions of the matrix. Without this, your second statement in the above paragraph does not hold.

Bourbaki covers the rank of both a linear map and of a matrix in detail, but does not mention the concept of maximal rank in any form. I'd posit that the concept of a maximal-rank matrix has little utility – little enough that I would trim the definition to an observation that when the terms maximal rank or full rank are used, these terms typically mean "[description here]". We have sufficient sources to make this diminished statement. —Quondum 00:25, 18 May 2015 (UTC)

It seems to me like you're extrapolating too heavily from your own experience. "Full rank" was immediately recognized and understood by my office mates; I wouldn't bat an eyelash seeing (or using) it in a research paper. And we have at least two RSs in this thread with definitions (thanks very much to those who found them!), while I doubt very strongly that anyone will produce a RS that deprecates the term in the way you suggest. --JBL (talk) 01:10, 18 May 2015 (UTC)

I think a suitable definition of maximal rank has become clear (and I suppose we can assume that 'full rank' is a synonym). But what do you make of four out of six RSs mentioned in this thread that cover matrix rank simply failing to mention it? Should we present it as though it is mainstream and significant as if every RS had mentioned it? I was hoping some consensus would emerge, but it seems to be slow in coming; the proposals I make are merely strawmen for consideration. —Quondum 03:32, 18 May 2015 (UTC)

Okay, never mind. I've tweaked the article in the direction of maximal or full rank being defined for nonsquare matrices. At least that gets rid of the internal inconsistency, and does not change the article much. I'm not going to belabour this any further. —Quondum 04:26, 18 May 2015 (UTC)

Thank you, I am happy with the final result. --JBL (talk) 20:46, 18 May 2015 (UTC)

In case you're still looking, I found a reliable source: David C. Lay, Linear Algebra and Its Applications, 1994, Addison-Wesley, p. 242, exercise 26: "In statistical theory, a common requirement is that a matrix be of full rank. That is, the rank should be as large as possible." [Italics are in the original.] Mgnbar (talk) 00:01, 16 May 2015 (UTC)

And by the way books by Kolman, Hoffman and Kunze, and Halmos don't seem to mention full rank. Mgnbar (talk) 00:04, 16 May 2015 (UTC)

I suggest we define either of 'full rank' or 'maximal rank' and provide the other one in an or-clause. While 'full column rank' and 'full row rank' both make sense, they don't seem to appear in the literature. Both imply 'full rank' and 'full rank' implies one or the other (or both) of them (if they were defined) supported by the theorem that says row-rank = column-rank. Lee defines 'maximal rank' for an m × n or n × m-matrix, n > m as one having a m × m minor of rank m. YohanN7 (talk) 17:05, 16 May 2015 (UTC)

I would hope we make no definition without it being a fairly standard term. That was why I initially requested some input: some sources clearly define full rank as the maximal rank for the matrix size, but if that is a minority definition, I would prefer to see to noted as such. If most sources use a different term, or define it some other way, we should document it accordingly. So far, no-one seems to have done more than consider an isolated source or so. I we have a few highly notable secondary sources defining it (how widely accepted is Lee?), we could do as you say. —Quondum 23:12, 16 May 2015 (UTC)

Well, Lee is no Bourbaki, he defines things on the fly (and is therefore readable as opposed to Bourbaki). My point is that it doesn't matter very much, just take one "reputable" reference at random, use it for the def and provide the alternative term. It can't get very much wrong. Unfortunately, my own supply of books in linear algebra is limited. YohanN7 (talk) 14:58, 17 May 2015 (UTC)

With a risk of complicating the discussion further, I would like to mention yet another point of view: "full-rank" = "maximal rank" = "generic-rank". Here, I'm using "generic" in the following way. Let X be the (vector) space of all matrices of some fixed size (possibly non-square). We view X as an (affine) algebraic variety (X is simply a vector space.) Then the matrices of maximal possible rank form an open subset with respect to Zariski topology (it is the complement of the vanishing locus of minors.) So, a matrix in a general position has maximal possible rank and that's the generic rank of a matrix. (Do I make sense?) By definition, a matrix is full-rank if it has generic rank or equivalently maximal possible rank. -- Taku (talk) 14:38, 17 May 2015 (UTC)

This vaguely resembles an example in Lee's book. The set of m × n matrices with full rank is open in M(m, n) in the subspace topology, hence a submanifold. YohanN7 (talk) 14:58, 17 May 2015 (UTC)

It is correct that "full rank" = "maximal rank", when considering the set of all m × n matrices. But, in the case of the a differentiable mapping, it may occur that the Jacobian matrix is never full rank, that is "maximal rank" < "full rank". On the other hand, when "generic rank" is defined (that is in the context of algebraic geometry), it is true that "maximal rank" = "generic rank". As an example of a situation where the term "full rank" is useful, and probably widely used, is the following result: Given a set of polynomials that generate a prime ideal, the algebraic variety of their common zeros is a complete intersection if the Jacobian matrix is "full-rank" at, at least, one point of the variety. In this case, the singular points are exactly the points where the Jacobian matrix is not full-rank. D.Lazard (talk) 09:56, 18 May 2015 (UTC)

In essence then, "maximal rank" is generally used for the supremum of ranks of a set (e.g. Jacobian matrices of a map) of matrices, while "full rank" applies to one matrix? YohanN7 (talk) 11:53, 18 May 2015 (UTC)

There is another case to consider: infinite-dimensional matrices. Because we can zero a column of a full-rank matrix without changing the rank, the rank remains maximal, but because the column span is no longer that of the resulting vector space (the map is no longer surjective), it is no longer of full rank. But this argument depends on whether the rank of a matrix is defined for infinite-dimensional matrices. —Quondum 14:19, 18 May 2015 (UTC)

I don't think "rank" is helpful for infinite-dimensional matrices unless finite; but my "natural" inclination is to consider "injective" rather than "surjective" as the definition of "full rank" for infinite-dimensional matricies. — Arthur Rubin (talk) 20:34, 18 May 2015 (UTC)

Isn't the matter settled? Don't we have two reliable sources for full rank (Gentle and Lay), ignoring bad spelling in the former? More sources don't explicitly define the term because they don't need it or its meaning is obvious? (I don't want to dictate conclusion of discussion. I'm just trying to figure out whether I need to keep paying attention.) Mgnbar (talk) 13:45, 18 May 2015 (UTC)

I'm treating the original question as settled (despite my personal reservations), though any further discussion may lead to tweaks, e.g. distinctions between "maximal" and "full". —Quondum 14:19, 18 May 2015 (UTC)

I agree. --JBL (talk) 20:46, 18 May 2015 (UTC)

I realize I'm late to the party, but thought I would chime in. The term "maximal rank" can be ambiguous. Consider the following statement:

Suppose that $f:\mathbb {R} ^{n}\to \mathbb {R} ^{m}$ is a continuously differentiable function, and let U be the set of points where the derivative of f has maximal rank.

A rather trivial example of the ambiguity is the constant function $f(x)=0$ for all x. The rank of the derivative is zero everywhere, so the maximum value of the rank of f is equal to zero! Thus (under this interpretation) $U=\mathbb {R} ^{n}$. Now, clearly for "most" applications, this is not the interpretation that would be intended by the statement. Rather, we would mean

Suppose that $f:\mathbb {R} ^{n}\to \mathbb {R} ^{m}$ is a continuously differentiable function, and let U be the set of points where the derivative of f has full rank.

Here full rank means that the rank of Df is as large as it can possibly be for an $m\times n$ matrix. Thus, the restriction of f to U is a submersion, if $n\geq m$, and an immersion, if $n\leq m$. Sławomir Biały (talk) 15:47, 18 May 2015 (UTC)

Considering the reservations expressed here (by D.Lazard and Sławomir Biały), I have removed my unsourced addition of 'maximal rank 'to Rank (linear algebra), leaving the definition of 'full rank'. —Quondum 03:57, 21 May 2015 (UTC)

Category ICM 2014 Plenary and Invited Speakers

I've just created the category for the ICM 2014 Plenary or Invited Speakers. A list with the names of the speakers can be found on http://www.mathunion.org/db/ICM/Speakers/SortedByCongress.php . If someone wants to help to add the category to more articles, be more than welcome! Lolaszvodikech (talk) 00:44, 22 May 2015 (UTC)

Off-topic: A mathematician named László Erdős is listed there! I wonder if he is a relative of Paul Erdős! Anyway, with such a name he must attract a lot of attention :). Lolaszvodikech (talk) 01:28, 22 May 2015 (UTC)

Face configuration

The article title Face configuration appears to be a neologism: neither Cundy & Rollett nor Williams, both cited, use the term. Rather, they use the symbol to identify the related polyhedron (typically a Catalan solid). I do not have Grünbaum and Shephard to hand, but I have never heard the term in this connection. The article makes much of Cundy & Rollett's (non-existent) usage. Do we accept this kind of apparently fabricated usage, or should this kind of article be nominated for deletion? — Cheers, Steelpillow (Talk) 11:47, 19 May 2015 (UTC)

Vertex configuration is another article in the same genre it would seem. Although possibly slightly less WP:ORish, the term "vertex configuration" (or the other synonyms listed there) do not appear to be in wide use. I think this article should be redirected to vertex figure. The notation can be mentioned there, without creating a neologism. I don't know if there is a suitable merge target for face configuration, though. Sławomir Biały (talk) 13:34, 19 May 2015 (UTC)

Face configuration is a fairly well known concept in a facial recognition system, possibly a notable topic in the geometric/parametric approach to facial recognition. I could not find sources describing the polyhedral version. --Mark viking (talk) 16:39, 19 May 2015 (UTC)

As stated, the two sources are Cundy-Rollett for Archimedean dual polyhedra and Grünbaum and Shephard for Monohedral/Lave tilings. Williams repeats the Cundy-Rollett symbol usage. Mathworld calls it a Cundy-Rollett symbol. I'm open to merging Vertex configuration and Face configuration as one article and calling both Cundy-Rollett symbol, like at [15]. Vertex figure is functionally different than vertex configuration, not a symbol but a n-dimensional polytope existing at a vertex. Tom Ruen (talk) 16:56, 19 May 2015 (UTC)

I cannot find reference to "Cundy-Rollett symbol" on Mathworld, only a passing reference to the "Cundy and Rollett symbol" for the Archimedean solids. Either way, use for the odd table column heading does not establish notability. The "functional difference" alluded to above is trivial: a "vertex configuration" is just a symbol denoting a certain kind of vertex figure, so I agree with Sławomir Biały that merging is a good way to go there. But Face configuration is not a recognised term and the thing it denotes is not notable either - witness the fact that the purported sources use it in a very minor way and don't even bother to give it a name. If anything in the article worth keeping can be found, it can be merged across into Face (geometry), but AFAICT there is nothing even to justify a redirect and the article itself should be deleted. — Cheers, Steelpillow (Talk) 19:22, 19 May 2015 (UTC)

It is a symbol, not a figure. And I'd rather keep it separate from Face (geometry) and collect it with vertex configuration, whatever might be called. Here's another newer reference for Archimedeans Cundy-Rollett symbol. Tom Ruen (talk) 19:44, 19 May 2015 (UTC)

"Cundy-Rollett symbol" gets just ten hits on Google, most of which are scrapings from here - and Popko's book, which mentions it only briefly. That is not enough to establish notability. — Cheers, Steelpillow (Talk) 21:13, 19 May 2015 (UTC)

Whatever you'd like to call it, it's used EVERYWHERE! Would you prefer something like A universal symbol that represents the sequence of vertex valances around a face of a polyhedron or tiling?! Tom Ruen (talk) 21:40, 19 May 2015 (UTC)

When you say "it's used everywhere", you really mean that you, personally, are responsible for adding it to a large number of our articles, right? Did you have sources when you did so? —David Eppstein (talk) 22:53, 19 May 2015 (UTC)

No, by "everywhere", I means every book or paper that talks about about regular, semiregular, uniform polyhedra and their duals. Tom Ruen (talk) 23:57, 19 May 2015 (UTC)

Surely such a prominent concept has an established name. Ozob (talk) 02:06, 20 May 2015 (UTC)

For the more popular vertex configurations, I've found 9 descriptive names for the symbol: vertex configuration, vertex figure, vertex type, vertex symbol, vertex arrangement, vertex pattern, face-vector, vertex description, and Cundy-Rollett symbol. Tom Ruen (talk) 05:58, 20 May 2015 (UTC)

That is because the symbol is part of the theory of uniform vertex figures and has no significance outside of that topic. Moreover its mathematical significance even within that topic is so trivial that nobody has ever bothered to agree an accepted name. All those other terms are mere ad hoc descriptions, because that is all it deserves. The "face configuration" is even less justifiable. — Cheers, Steelpillow (Talk) 07:24, 20 May 2015 (UTC)

Sourcing?

Now I find myself being reverted. The article at Vertex configuration gives "Cundy-Rollett symbol" as a synonym and cites mathworld. As I pointed out above, mathworld does not in fact use this term and the cite is therefore incorrect. As I also pointed out, one lone author does not establish notability. However when I removed the reference Tom Ruen chose to revert my edit without comment. Is this behaviour acceptable to this Project? — Cheers, Steelpillow (Talk) 07:04, 20 May 2015 (UTC)

I restored the removal, and added a second source, and commented on the second source in the revert. Tom Ruen (talk) 08:48, 20 May 2015 (UTC)

No you have not restored my removal. You have moved it to the article lead and wrapped a whole load more trivial sources around it. I have to ask again, is this behaviour acceptable to this Project? — Cheers, Steelpillow (Talk) 19:05, 20 May 2015 (UTC)

I said I restored what you removed and I added a second reference along with my revert, and I named the second reference in the comment. I did not revert "without comment". After that I continued to improve the content as a good editor should. You can see "trivia" as you like, but my intention was to demonstate varied ways the symbol was named. If someone reads the article, they can check the usages and decide for themselves which name has the best legitimacy or whatever. Tom Ruen (talk) 03:40, 21 May 2015 (UTC)

Nevertheless, you reverted me. The tenor of this discussion is that thse sources are inadequate and you should not have done so. Yet you persist in embellishing them while the discussion continues. — Cheers, Steelpillow (Talk) 08:08, 21 May 2015 (UTC)

I'll let smarter people than me validate your confusing charges against me. I've done NOTHING but try to please you, and all you see is insult. Tom Ruen (talk) 09:59, 21 May 2015 (UTC)

So, reverting me is trying to please me. I'll remember that next time I want to try and please you. — Cheers, Steelpillow (Talk) 12:24, 24 May 2015 (UTC)

Indeed. removing-without-improving and reverting-with-improving might weigh as equal acts of kindness. Tom Ruen (talk) 19:28, 24 May 2015 (UTC)

Another sourcing

Tom Ruen (talk) 09:50, 20 May 2015 (UTC)

Physical Metallurgy: 3-Volume Set, Volume 1, edited by David E. Laughlin,

Page 16 The Cundy and Rollett symbol of a vertex configuration nm means that m n-gons meet at a vertex. The vertex configuration can also be written in the form of the Schlafli symbol {n,m} or (n,m). The eight semiregular Archimedean tilings are uniform. This means they have only one type of vertex configuration, i.e. they are vertex transitive; they consist of two or more regular polygons as unit tiles. In the case of layer structures, where one layer type corresponds to one of the Archimedean tilings, the layer next to it will preferentially be the respective dual tiling (Catalan or Laves tiling). The dual to a tiling can be obtained by putting vertices into the center of the unit tiles and connecting them by lines. If the tiling is regular, then the dual tiling will be regular as well. The dual of the regular square tiling is a regular square tiling again, so this tiling is self-dual. The dual to the hexagon tiling is the triangle tiling. While the uniform semiregular tilings are described by their vertex configuration, their duals consistent of just one type of polygon (are isohedral), but have more than one vertex configuration. Therefore, they are described by their face configuration, i.e. the sequential numbers of polygons meeting at each vertex of a face. For instance, the dual to the Archimedean snub square tiling 32.4.3.4 is the Cairo pentagon tiling, V32.4.3.4. Its face configuration V32.4.3.4 means pentagonal unit tile with corners, where 3,3,4,3,4 squashed pentagons meet.

page 20 The Archimedean solids can all be inscribed in a sphere and in one of the Platonic solids. Their duals are the Catalan solids, with faces that are congruent but not regular (face-transitive); instead of circumspheres like the Archimedean solids, they have inspheres. The midsphere, touching the edges are common to both of them. The face configuration is used for the description of these face-transitive polyhedra. It is given by the sequential listing of the number of faces that meet around each vertex around a face. For instance, V(3.4)2 describes the rhombic dodecahedron, where at the vertices around one rhombic face 3,4,3,4 rhombs, respectively, meet.

I'm not sure this is the best source for establishing standard usage in geometry. Apart from the obvious issue that this is a metallurgy textbook (and the terminology does not seem to be standard in metallurgy either), the neologism appears only in the fifth 2014 edition, long after we had an encyclopedia article on the subject. Also, the description that appears on page 20 is a paraphrase of our article on the subject, including the same choice of example. So it seems that one source has merely picked up our neologism. An encyclopedia should merely reflect what is already standard; it should not be in the business of inventing new standards. Sławomir Biały (talk) 12:04, 20 May 2015 (UTC)

It looks like a large fraction of the content above was referenced and taken from Crystallography of Quasicrystals: Concepts, Methods and Structures by Walter Steurer, Sofia Deloudi, (2009) p.18-20, p.51-53. Tom Ruen (talk) 10:23, 21 May 2015 (UTC)

Yes, this seems like a better source. Sławomir Biały (talk) 13:15, 22 May 2015 (UTC)

The oldest source I can find using the phrase vertex configuration is this 1993 paper on the uniform star polyhedra: [16]. Pretty much ALL the online constructions of the uniform stars trace back to this paper, of course the original source is the Coxeter 1954 paper on uniform polyhedra which draws the diagrams as polygons rather than listing the n-gons. Tom Ruen (talk) 10:33, 21 May 2015 (UTC)

• Uniform Solution for Uniform Polyhedra*
• Zvi Har’El
• Department of Mathematics, Technion − Israel Institute of Technology, Haifa 32000, Israel, E-Mail: rl@math.technion.ac.il
• ABSTRACT: An arbitrary precision solution of uniform polyhedra and their duals is presented. The solution is uniform for all polyhedra given by their kaleidoscopic construction, with no need to ‘examine’ each polyhedron separately.

I'd summarize and conclude Cundy and Rollett symbol is a good name for this notation for giving credit for their 1952 book Mathematical models, first published book expressing the convenient notation for the (convex) regular, semiregular, and semiregular dual polyhedra, as integers a.b.c. ... Then Zvi Har’El's 1993 paper extend that usage as vertex configuration and may get first credit for the first consistent notation for the uniform stars and duals, which include full orientation information (prograde/retrograde) and wrap information, which makes the stars explicitly constructable: like (a/b . c/(d-c) . ... x/y)/z. Roman E. Maeder then ported it into Mathematica around 1995, using the same terminology, while Robert Webb used it in Stella around 2001, but instead calling it a vertex description. Tom Ruen (talk) 11:22, 21 May 2015 (UTC)

In parallel, and a bit earlier Tiling and Patterns (1987) uses a similar more general notation for Euclidean tilings, calling the notation tile symbols or of type. It also has hollow tilings with star polygons and retrograde orientation, using negatives for retrograde, so somewhat similar to Zvi Har’El's star polyhedra usage. Tom Ruen (talk) 11:44, 21 May 2015 (UTC)

First article about Indonesian mathematician on WP-En

Hello. I've just created the first page about any mathematician from Indonesia at the English Wikipedia. The name of the page is Moedomo Soedigdomarto. My English is not very good, and the sources are all in Indonesian (my 3rd language, which I don't know very well too...) Anyway, if someone wants to help. Please feel free to join the effort. Chinese-Indonesian (talk) 08:46, 26 May 2015 (UTC)

Looks like a nice start, especially for someone who is not a native English-speaker, good job! But links (like the first two references 1 and 2) in Latin-alphabetized Indonesian are not too helpful for English speakers in English Wikipedia. Also, strong claims like "He was one of the first Indonesians" need to be cited. If possible please add more English sources. M∧Ŝc²ħεИ_τlk 10:34, 26 May 2015 (UTC)

Lecture notes as a reference?

See recent edits at Brouwer fixed-point theorem, and also my talk page. I think lecture notes are sometimes okay and sometimes not depending on what is available. In this case, a simple Google search will give millions of hits, and I don't see the need to have lecture notes linked. YohanN7 (talk) 11:38, 24 May 2015 (UTC)

Any lecture notes, particularly the terabytes of pdf notes floating around, should just be external links not references, they are not published mainstream secondary sources. M∧Ŝc²ħεИ_τlk 10:37, 26 May 2015 (UTC)

These are external links (didn't start out that way though), so I guess it is fine. Not a huge fan of the practice though. Why should we "promote" or "endorse" them? YohanN7 (talk) 10:45, 26 May 2015 (UTC)

It isn't "promotion" or "endorsement", I thought the purpose of external links is to point to other sources of info which are not considered reliable and are not secondary but have at least some usefulness. M∧Ŝc²ħεИ_τlk 10:49, 26 May 2015 (UTC)

There is a difference between neutral links to MathWorld and the like and lecture notes. But I have myself committed the crime (actual references, not external links) on occasion when nothing else has been available to me. See this more like me asking a question than pushing a POV (thought my posts look and sound like POV pushing) YohanN7 (talk) 11:18, 26 May 2015 (UTC)

I would say it depends on the circumstances. Even lecture notes by a well-known authority can be used as references (with care, and assuming there are no better sources available), per WP:SPS. I would say that this source is a good one. The chapter discusses the degree of a mapping from the perspective of multivariable calculus. The Brouwer theorem is a consequence of the homotopy invariance of the degree of a function. This is something that could, in principle, be added to the article, since the connection with degree is not really made clear. Sławomir Biały (talk) 12:19, 26 May 2015 (UTC)

I can buy that in full. As a side note, both Steven Willard (General Topology) and John M. Lee (Introduction to Topological Manifolds) handle it using homotopy theory (unless my memory fails). Especially Willard's proof was kind of neat, I recall, (and super-short). Will check this out. YohanN7 (talk) 13:38, 26 May 2015 (UTC)

Jun 2015

Formal linear combination

This notion is used, for example, in "Chain (algebraic topology)", with a link to "Free abelian group"; there, "formal sums" are defined (but "formal linear combinations" are not). In some books I see "formal linear combinations" used with no definition (and often, with no explanation). Once I used it on an undergraduate lecture and was asked by students: "what's it?"

Should we redirect "Formal linear combination" to "Free abelian group"? Should we enlarge the latter, including non-integer coefficients? Boris Tsirelson (talk) 17:27, 31 May 2015 (UTC)

Free module seems like a better target, although that article could use improvement. Sławomir Biały (talk) 17:56, 31 May 2015 (UTC)

For now it does not mention "formal linear combinations". Boris Tsirelson (talk) 19:02, 31 May 2015 (UTC)

The book Introduction to Topological Manifolds by John Lee introduces "formal linear combinations" in the context of free Abelian groups. --Mark viking (talk) 18:39, 31 May 2015 (UTC)

I guess, it uses only integer coefficients; but (at least) real coefficients are really needed in the context of Stokes theorem.

I also bother that "free module unique up to isomorphism" is demanding for some readers that could be satisfied with "finitely supported functions on the set of (...)". Boris Tsirelson (talk) 19:02, 31 May 2015 (UTC)

I have rewritten the corresponding section of Free module for defining explicitly formal linear combination (and also for being less technical). I have also created the redirect Formal linear combination. D.Lazard (talk) 09:17, 1 June 2015 (UTC)

Very nice; now I can recommend it to my undergraduates. Boris Tsirelson (talk) 15:32, 1 June 2015 (UTC)

Now if only someone could do something about that lead paragraph ;). --JBL (talk) 19:44, 1 June 2015 (UTC)

Mathematical logic and Goedel sentences

Please take a look at mathematical logic. --Trovatore (talk) 18:30, 26 May 2015 (UTC)

Also axiom, please. --Trovatore (talk) 04:19, 27 May 2015 (UTC)

What is the problem with those articles? — Arthur Rubin (talk) 23:53, 28 May 2015 (UTC)

If I read the talk page correctly, it involves a philosophical debate between a Platonic position in which one can say that a first-order sentence about the integers is true of "the" integers (even if it might be false for some models of the Peano axioms), and a radically relativist position in which sentences may be stated to be true of models but not true in any absolute sense and in which no model of Peano's axioms (not even the model given by the finite ordinals) is privileged as being "the" integers. This affects the article in terms of whether it is more accurate to say that the Gödel sentence is "true, but unprovable" or "neither it nor its negation are provable". —David Eppstein (talk) 01:13, 29 May 2015 (UTC)

Not quite: it's about whether a first-order sentence should be said to be true without qualification, or true of the integers. But anyway it's resolved. --Sammy1339 (talk) 04:13, 29 May 2015 (UTC)

Sorry that I missed this debate :-) --GodMadeTheIntegers (talk) 18:00, 2 June 2015 (UTC)

Oh yes; according to your username, you should be platonistic. :-) Boris Tsirelson (talk) 18:10, 2 June 2015 (UTC)

Fundamental lemma of calculus of variations

Much weakened version of that lemma is formulated in our article. The reason (articulated on the talk page) is that the simple proof given in the article does not give more. As for me, irrespective of the proof, a stronger formulation should be given. But for now I have only lecture notes as sources. I wonder, do you know better sources? Mine are:

• M.Bendersky, course, pp.10-12 in [17];
• G.K. Ananthasuresh, course, Lecture J, the four lemmas in [18].

Boris Tsirelson (talk) 11:53, 29 May 2015 (UTC)

Wikipedia isn't in the business of giving proofs we should be pointing to textbooks for that, though of course trying to explain it is an important part of Wikipedia's business. I must admit I can't see why it has been split or forked out of the article on the calculus of variations, it isn't as though that article is too big and this is a very important part of it. Dmcq (talk) 12:36, 29 May 2015 (UTC)

Of course if you can expand that article with another formulation then of course it deserves its own article, it just seemed rather short and a duplication of bits of the main article to me at the moment. Dmcq (talk) 12:53, 29 May 2015 (UTC)

Well, I am neutral about possible merge. I bother that the optimal function should be proved to be smooth, rather than assumed. That is, in the fundamental lemma, the given function "orthogonal" to all smooth functions must vanish even if not assumed smooth. I could expand; the problem is, whether "my" sources are reliable enough. Boris Tsirelson (talk) 13:44, 29 May 2015 (UTC)

I'm not entirely clear on your objection. Do you want to strengthen the lemma by saying that $h\in C^{\infty }$ instead of just $C^{k}$? That would be the grownup way to write this; it would involve bump functions instead of the current proof (which is kind of cute nonetheless). --Sammy1339 (talk) 15:06, 29 May 2015 (UTC)

Oh I see. Yes it should be strengthened. --Sammy1339 (talk) 15:06, 29 May 2015 (UTC)

Smoothness of h matters, too. But I mostly bother about smoothness of f. Boris Tsirelson (talk) 15:18, 29 May 2015 (UTC)

(Edit conflict) Really, that lemma should be treated as a special case of the fact that every weak solution of a linear ODE is also a strong solution. Regretfully, I did not find this fact in our article "weak solution" (nor in "distribution"). I also did not find this connection in texts on calculus of variations. Is it my Original Research?! Boris Tsirelson (talk) 15:36, 29 May 2015 (UTC)

I just looked in Gelfand & Fomin and interestingly they follow the exact same steps as your sources above, but this formulation is neither stronger nor weaker than what appears in the article. You require a stronger hypothesis ($\forall h\in C^{2}$ instead of just $\forall h\in C^{k}$.) Then there is Lemma 4 in your sources above (which is also Lemma 4 in G&F on p. 11) which is just integration by parts basically showing that if $f$ is continuous and weakly differentiable then it is differentiable. --Sammy1339 (talk) 15:28, 29 May 2015 (UTC)

Ah, yes, it is nice to know that Gelfand & Fomin is a good source! Given that you have this book while I do not (for now), maybe you'll improve the article accordingly? Boris Tsirelson (talk) 15:39, 29 May 2015 (UTC)

And yes, "if $f$ is ... weakly differentiable then it is differentiable" is just what I want to see. Boris Tsirelson (talk) 15:42, 29 May 2015 (UTC)

I'm looking for a source for that which states it full generality. --Sammy1339 (talk) 15:58, 29 May 2015 (UTC)

It seems, you are busy... Meanwhile I took books (including Gelfand & Fomin, thanks for the advice), got bold, and rewrote the article. Still, do better, as much as you can (and want). Boris Tsirelson (talk) 20:13, 2 June 2015 (UTC)

See theorems 1.2.4 and 1.2.5 in volume 1 of Hörmander. If f is a continuous (resp. locally integrable) function st for all compactly supported smooth φ

$\int f\phi =0$

then f=0 (resp f=0 a.e.) Sławomir Biały (talk) 16:47, 29 May 2015 (UTC)

poincare conjecture incident

There is an ongoing and somewhat agitated discussion of the Poincare conjecture here. Tkuvho (talk) 13:37, 3 June 2015 (UTC)

Vietoris–Rips complex

The page on the Vietoris–Rips complex lacks a formal definition written in a readable format. Please fix thanks. — Preceding unsigned comment added by 98.223.78.42 (talk) 14:40, 3 June 2015 (UTC)

What's wrong with the definition in the first sentence, and its expansion in the rest of the first paragraph? —David Eppstein (talk) 15:55, 3 June 2015 (UTC)

Lagrange's method

Currently Lagrange's method redirects to Lagrange multiplier, but apparently in the world of PDE's, Lagrange's method means something entirely different. For example, see [19]. Do we cover the PDE meaning of Lagrange's method? Is seems like if it's anywhere it would be in First-order partial differential equation but I didn't see it in recognizable form, though it's not my area of expertise. --RDBury (talk) 12:20, 4 June 2015 (UTC)

It's another name for the method of characteristics, but I don't think it's in very wide use. Sławomir Biały (talk) 13:02, 4 June 2015 (UTC)

I'm confused then because the pdf above gives Lagrange's method in chapter 3 and Method of Characteristics is chapter 4. The WP article on Method of Characteristics seems to follow chapter 3 more than chapter 4 though. My Google search turned up 4 or 5 more PDE books with sections on "Lagrange's Method" and a few stack exchange/mathoverflow posts that reference it, so while it might not be the most common it seems to have enough usage to be noted in the article as an alternate name. Perhaps a DAB page is in order, though the Springer EoM gives a | third meaning for "Lagrange's Method" which diagonalizes a quadratic form. --RDBury (talk) 15:45, 4 June 2015 (UTC)

Mass changes of style

I notice a set of mass changes to some articles. --Ancheta Wis   (talk | contribs) 04:57, 7 June 2015 (UTC)

These are very, very strange. I get the feeling that the anon has very specific epistemological ideas that he (?) would like Wikipedia to adhere to, but I'm not sure if I'm correctly understanding what's going on. Ozob (talk) 05:04, 7 June 2015 (UTC)

I just undid the one at Entscheidungsproblem. It seems to be a mix of style changes and an additional paragraph. The style changes, frankly, suggest that the editor is not a native speaker despite the fact that the IP geolocates to Ohio; but he/she could be a foreign student or something; I saw no reason to keep them. The additional paragraph I have not yet read — that seems to be an orthogonal issue. --Trovatore (talk) 05:14, 7 June 2015 (UTC)

Actually, at a second look, I don't think there is an additional paragraph after all. The editor had put some paragraphs in a different order or a different section. --Trovatore (talk) 05:18, 7 June 2015 (UTC)

Status of new article Complex spacetime

This may be of interest to those on this talk page: as I stated at Wikipedia talk:WikiProject Physics#Status of new article Complex spacetime, this new article might need some broader scrutiny. —Quondum 14:18, 10 June 2015 (UTC)

Orphaned conjugacy-closed subgroup

Conjugacy-closed subgroup is an orphaned article: no other articles link to it. Michael Hardy (talk) 23:22, 10 June 2015 (UTC)

Wikipedia:Articles for deletion/Quaternion rotation biradial

Opine on a proposed deletion at Wikipedia:Articles for deletion/Quaternion rotation biradial. Michael Hardy (talk) 17:34, 14 June 2015 (UTC)

Planetmath changed links format

It seems that some of the links to PM in Wikipedia articles are not working. For example, the following link [20] in the article Hartogs' theorem is not working. It was added using the Template:PlanetMath attribution. New link seems to be [21]. Also the link [22] in Ancient Egyptian multiplication does not work. The new link is [23]. This probably influences many articles (and templates). What ca be done with it? Can this be resolved automatically, or is manual change the only way to go? --Kompik (talk) 08:03, 15 June 2015 (UTC)

By the way, this might be an old problem which I noticed only now. Already this revision of Hartog's theorem from September 2014 contains information that the link is not working. So it is quite probable that this has already been discussed somewhere. --Kompik (talk) 08:07, 15 June 2015 (UTC)

We might be able to change the template for some of the entries. The EgyptianMultiplicationAndDivision could be fixed by changing the line

[http://planetmath.org/encyclopedia/{{{urlname}}}.html

to

[http://planetmath.org/{{{urlname}}}

A bit more testing will be needed to see if this works for all the occurrences. There are 280 transclusions[24] so its not an impossible task.--Salix alba (talk): 14:44, 15 June 2015 (UTC)

It was discussed at Template talk:PlanetMath attribution but it does not look like any action was taken. It seems like the id's need to have 30000 added to them so http://planetmath.org/node/6024 needs to be changed to http://planetmath.org/node/36024.

It seems like {{PlanetMath reference}} and {{PlanetMath}} were already fixed. I think I've now fixed {{PlanetMath attribution}}.--Salix alba (talk): 15:35, 15 June 2015 (UTC)

Quotient structure

We seem to have no article on quotient structures in general. We have Quotient (disambiguation), which lists a bunch of things as if they were different things known by the same name, with no idea common to all of them. Should we have a quotient structure article? Michael Hardy (talk) 18:18, 15 June 2015 (UTC)

However, we have "substructure", and maybe indeed "quotient structure" could be similar. There I see: "Substructures as subobjects"; and in "Subobject" I see: "The dual concept to a subobject is a quotient object". Boris Tsirelson (talk) 20:28, 15 June 2015 (UTC)

Quotient structure is discussed a little in Congruence relation. I guess that quotient structure is more of a universal algebra thing and quotient object is more of a categorical thing. Both could usefully be discussed in one article, along with concrete examples. --Mark viking (talk) 20:49, 15 June 2015 (UTC)

Quotient space redirects to Equivalence relation, in which the subject is sketched. Epimorphism is also (or should be) related. It is not clear to me what deserves to be added. So, for the moment, I suggest to redirect quotient structure to Equivalence relation, and to add to this article the few things that are lacking (which?). D.Lazard (talk) 21:18, 15 June 2015 (UTC)

Deletion sorting for Math articles?

Is there deletion sorting for mathematics-related articles or do they just end up under Wikipedia:WikiProject Deletion sorting/Science?

Anyway there are three articles at AfD about algorithms for voting systems, not sorted into anything technical:

• Wikipedia:Articles for deletion/Proportional approval voting (3rd nomination)
• Wikipedia:Articles for deletion/Sequential proportional approval voting (2nd nomination)
• Wikipedia:Articles for deletion/Satisfaction approval voting

Thanks for looking at these. StarryGrandma (talk) 23:05, 19 June 2015 (UTC)

No new articles

At Wikipedia:WikiProject Mathematics/Current activity, we find no new articles since May 25. Jitse's bot, run by Jitse Niesen, which edits that page, has done so more recently, and mathbot, which, among other things, lists new articles, whose lists are used by Jitse's bot, has been active more recently. Are there no new articles? Michael Hardy (talk) 18:44, 31 May 2015 (UTC)

Are you looking at the same current activity that I am? Because I see 14 new articles on May 26 (starting with Alicia Dickenstein), 6 new articles on May 28, and a large number of new articles (possibly caused by moving some category involving tilework into the ones the bot lists) on May 29. —David Eppstein (talk) 19:17, 31 May 2015 (UTC)

Yes, there a many entries dated after May 25. A diff shows them. I see "This page was last modified on 31 May 2015" at the bottom of Wikipedia:WikiProject Mathematics/Current activity. If you se an older date then try to bypass your cache. PrimeHunter (talk) 19:26, 31 May 2015 (UTC)

• Speaking of which, we have several mathematical article submissions such as Draft:Loewner order or Draft:Contributions on developping measuring tools on surfaces up for review at the moment. Care to offer your thoughts? Cheers, FoCuSandLeArN (talk) 21:10, 2 June 2015 (UTC)

The second article is not suitable I would say, as it duplicates content that is already in a much more readable form elsewhere in the encyclopedia. The first is certainly an encyclopedic topic, but the name "Loewner order" is not very standard. Most mathematicians would not attribute this to Loewner, just calling it the partial ordering of hermitian matrices. Sławomir Biały (talk) 19:51, 5 June 2015 (UTC)

I'm experiencing the same problem described by user Michael Hardy... Currently, the last date I can see on the "New articles:" section on the table is "5 Jun". But there were indeed mathematical articles created after 5 Jun (Yair Minsky (6 Jun) and Richard Canary (7 Jun) are proof of this). — Preceding unsigned comment added by 189.6.195.23 (talk) 13:24, 8 June 2015 (UTC)

The bot has been having problems on and off for a couple of months. See the last two sections of User talk:Jitse's bot. I've tried pinging and e-mailing Jitse Niesen but have had no response. I don't know if there's anything else that can be done, such as someone else take over maintaining them.--JohnBlackburne^words_deeds 13:32, 8 June 2015 (UTC)

There are two bots involved, mathbot and Jitse's bot. But in this case, mathbot appears to be picking up the new articles; it's the updates to the current activity page by Jitse's bot that have gone missing. —David Eppstein (talk) 17:45, 8 June 2015 (UTC)

Jitse Niesen has not made any contributions since 10:54, 20 October 2014, so I am afraid that we must assume that he is unable or unwilling to participate further in the English Wikipedia. JRSpriggs (talk) 04:03, 9 June 2015 (UTC)

If Jitse Niesen has left us, does someone inherit his bot? Will the Mathematics Wikiproject collapse permanently if his bot dies? Michael Hardy (talk) 23:48, 10 June 2015 (UTC)

What does it take to run a bot? Do we or can we use a sever at the wikimedia foundation? It would be nice, long term, if we can rely on an institution instead of an individual editor. (Right now, we are in the post-apocalyptic world, I suppose.) -- Taku (talk) 23:14, 19 June 2015 (UTC)

Relations

Are Dependence relation and Dependency relation the same thing? WhatamIdoing (talk) 03:13, 22 June 2015 (UTC)

No. Completely different. And probably, both are not widely used. Boris Tsirelson (talk) 05:51, 22 June 2015 (UTC)

Rfd for Category of graded vector spaces

Hi there.

Over at Wikipedia:Redirects_for_discussion/Log/2015_June_20#Category_of_graded_vector_spaces this has been listed. I think it is redundant and perhaps harmful since it is not a Wikipedia catgegory but a redirect to an article: surely the grading/graduation is itself the way to categorise them so to categorise the grading would be some higher order function, which I'm sure is not intended here. (To categorise the categorisation, i.e. in formal logic of some kind, Bertie Russell turning in his grave).

I only have maths up to basic graduate degree level, and mostly on the engineering side of it rather than theory, so I'd appreciate your opinion on whether this is useful. Si Trew (talk) 07:22, 22 June 2015 (UTC) see my userpage on 3d slope formula here — Preceding undated comment added 00:34, 23 June 2015 (UTC)

What formula is this?

I am in the process of renaming two-letter filenames on Commons, to provide less ambiguous titles. Today I came across this one:

What is this equation? Or, more directly, what would be an appropriately unambiguous, but concise, name for this image file? Cheers! bd2412 T 19:55, 24 June 2015 (UTC)

A good question to the person that uploaded it. Boris Tsirelson (talk) 21:10, 24 June 2015 (UTC)

The person who uploaded it seems to be a ghost. They appeared on Commons a month ago, uploaded a dozen and a half images like this, and disappeared. Are these anything at all? bd2412 T 21:24, 24 June 2015 (UTC)

Perhaps it's time to exorcise the ghost? — Arthur Rubin (talk) 21:50, 24 June 2015 (UTC)

If these images are useful, we should keep and properly describe them. If they are not, they should be deleted. I don't have the background to determine whether these are at all meaningful. bd2412 T 22:19, 24 June 2015 (UTC)

These appear to have something to do with magnetism and perhaps magnetic flux. Equations are better written in the text and I don't mean to be harsh, but the illustrations are small enough that they probably aren't too useful. --Mark viking (talk) 22:55, 24 June 2015 (UTC)

It does not seem to be used anywhere. We should delete it. JRSpriggs (talk) 09:17, 25 June 2015 (UTC)

The Assayer

The book The Assayer by Galileo is one of the works that ushered in the scientific method as well as the method of indivisibles closely related to Galileo's atomism. Recently I added sourced material on this aspect of the book. Input would be appreciated. Tkuvho (talk) 07:36, 25 June 2015 (UTC)

Context: Tkuvho is engaged in a content-based edit war over the relevant material; he and User:William M. Connolley have both been blocked for 24 hours as a result. There are no obvious signs of consensus-forming. Probably, the input of some neutral editors would improve the situation. --JBL (talk) 13:12, 25 June 2015 (UTC)

Dualizing sheaf listed at Redirects for discussion

An editor has asked for a discussion to address the redirect Dualizing sheaf. Please participate in the redirect discussion if you have not already done so. Ivanvector (talk) 14:48, 25 June 2015 (UTC)

Copyright Violation Detection - EranBot Project

A new copy-paste detection bot is now in general use on English Wikipedia. Come check it out at the EranBot reporting page. This bot utilizes the Turnitin software (ithenticate), unlike User:CorenSearchBot that relies on a web search API from Yahoo. It checks individual edits rather than just new articles. Please take 15 seconds to visit the EranBot reporting page and check a few of the flagged concerns. Comments welcome regarding potential improvements. These likely copyright violations can be searched by WikiProject categories. Use "control-f" to jump to your area of interest.--Lucas559 (talk) 22:25, 25 June 2015 (UTC)

Another terminology problem: what is a metric?

The word "metric" is used differently in (1) the context of a metric space, and (2) such context as "the metric of space-time".

A manifold with a metric tensor is called a pseudo-Riemannian manifold. (Quoted from "Metric (mathematics)#Important cases of generalized metrics".)

A special case of great importance to general relativity is a Lorentzian manifold, in which one dimension has a sign opposite to that of the rest. (Quoted from the lead of "Pseudo-Riemannian manifold".)

Thus, sometimes a space endowed with a metric is not a metric space. Regretfully, this confusing situation is not explained enough in our articles. See the ongoing dispute: Talk:Metric space#Questions to User:Verdana Bold about a recent attempt to emphasize the "more physical" usage of the word "metric". Indeed, that usage is notable and should be mentioned. However, this should be made carefully enough. Boris Tsirelson (talk) 17:35, 27 June 2015 (UTC)

Ceci N'est Pas Un Cercle

There is a silly argument going on between myself and two other editors at the new article real projective line about whether $\mathbb {R} P^{1}$ "really" is a circle. At first, it was argued that it must be homeomorphic but not diffeomorphic to a circle, because the universal cover of $S^{1}$ is $S^{1}$, and that of $\mathbb {R} P^{1}$ is $S^{1}$, and the property of being one's own universal cover is a diffeomorphism invariant - fortunately this argument was dropped. Then it was argued that it may be topologically equivalent to a circle, but have a different geometric structure, but later it was accepted that the natural metric makes $\mathbb {R} P^{1}$ isometric to a circle. Presently it is argued (I think) that there is some intermediate structure, stronger than the topological structure but weaker than the metric space structure, wherein cross-ratios of four points can be defined without reference to any distance function. I believe this is impossible; defining the cross-ratio (and proving that it is well-defined) requires using the metric. The reason this is significant is that I believe it is important to state clearly in the lede that the object is a circle, without reference to terminology that may confuse laymen, such as "homeomorphic," "isometric," or "birationally equivalent." This is the text I want:

In mathematics, the real projective line is a circle. It is a trivial example of a more general class of topological spaces known as projective spaces. The real projective line is formed from lines through the origin in two-dimensional space. One considers these lines to be the "points" of the real projective line, and the angle between them to be the "distance" between these "points." Formally, the lines through the origin form equivalence classes, allowing for the real projective line to be defined as a quotient space.

Having this context in mind may give the reader a better chance of understanding the technical details that follow. I think the importance of stating clearly that we are talking about nothing other than a complicated way to define a circle is shown by the talk page itself. Even a relatively mathematically-sophisticated reader might see "a space homeomorphic to a circle" and think that it has some other geometric structure, that it is a double cover of a circle, or whatever. This is what led a normally quite competent editor to the logical and factual fallacies in the "homeomorphic but not diffeomorphic" argument above; he was trying too hard to rationalize a wrong idea, when the truth was just too simple. On a related note, the article is also suffering from the idea that the group $PSL_{2}(\mathbb {R} )$ is the "automorphism group" of the real projective line. I think that someone just made this up. It is now the central principle in the platform of the "not a circle" party. --Sammy1339 (talk) 13:49, 26 June 2015 (UTC)

For understanding the context of this post, I recommend to the reader to consult Talk:Real projective line § Is the projective line a circle?. I have nothing to add to my posts in this discussion, especially the last ones. D.Lazard (talk) 14:09, 26 June 2015 (UTC)

"Obviously" a projective line is not a circle (real or otherwise). There can be an isomorphism between the two depending on a category in the context; say, one is working in the category of topological spaces, but such an isomorphism is not the equality ("is"); a morphism ceases to make sense once you step out of the category. -- Taku (talk) 17:04, 26 June 2015 (UTC)

For example, saying "a projective line a twisted cubic curve" is at worst wrong or at best very misleading; you can't replace an isomorphism by an identity. -- Taku (talk) 17:22, 26 June 2015 (UTC)

But (correct me if I'm wrong) there's no category in which they are not isomorphic. --Sammy1339 (talk) 19:09, 26 June 2015 (UTC)

I don't know if it would ever occur to me to read the word "circle" as referring to an intrinsic abstract manifold, even one with a metric. To me the word implies an embedded circle, the set of all points in some larger (usually Euclidean) metric 2-manifold equidistant from a given point. Is there some natural way of identifying such an embedding space in the case of the real projective line? --Trovatore (talk) 19:16, 26 June 2015 (UTC)

Well, I think of "circle" as meaning an intrinsic manifold, but if you want to look at it that way, then yes, there is: take $\mathbb {C} ^{2}$ and form the complex projective line (Riemann sphere), and look at what happened to the two real axes. They became a great circle, formed by the real line and the point at infinity. --Sammy1339 (talk) 19:33, 26 June 2015 (UTC)

But this doesn't seem to be exactly inherent in the notion of the real projective line. I think this is the basic problem. The real projective line is intrinsic, whereas the circle is embedded. Therefore they are not the same. --Trovatore (talk) 19:40, 26 June 2015 (UTC)

So would it be appropriate to say it's an "abstract circle?" --Sammy1339 (talk) 19:42, 26 June 2015 (UTC)

Possibly. --Trovatore (talk) 19:43, 26 June 2015 (UTC)

Just so we understand each other though, is the Riemann sphere not a sphere? --Sammy1339 (talk) 19:47, 26 June 2015 (UTC)

No, for the same reason; in fact, our very own Riemann sphere doesn't say so in the first paragraph (it defines it as a one-point compactification of the complex plane, which is correct; in fact, even more correctly it uses the term "model"). Interestingly, complex projective line redirects to "Riemann sphere", which is probably ok. By analogy, should real projective line redirect to a "circle"? Am I the only one who thinks that's crazy? Having separate articles already suggests the two concepts (RP¹, S¹) are distinct. -- Taku (talk) 22:47, 26 June 2015 (UTC)

Of course the article Riemann sphere calls the Riemann sphere a sphere -- any time you have a construction "the [adjective] [noun]," you can expect the reader to understand that you are speaking of a kind of [noun] unless you say otherwise, and this does not require special mention. (In mathematics sometimes it is the case that an [adjective] [noun] is not actually a [noun], and in this situation one can expect to find somewhere an explanation of this situation, e.g., "The terminology is somewhat confusing: every topological manifold is a topological manifold with boundary, but not vice versa.")

I do not have strong feelings about the underlying debate, but I certainly would not have thought to criticise or correct someone who referred to RP^1 as a circle. --JBL (talk) 23:07, 26 June 2015 (UTC)

I should have phrased it differently. Is $S^{2}$ with the spherical metric a sphere? --Sammy1339 (talk) 01:47, 27 June 2015 (UTC)

@Sammy : If one defines distance between two points on a circle to be the length of the chord between them, then that is topologically but not metrically equivalent to the circle intrinsic metric in which the distance is the arc length. Might that be the circle that is not isomorphic to the projective line, or is the chord-length metric a natural thing to use for that? As far as cross-ratios go, linear fractional transformations on the complex numbers take circles to other circles while changing distances but leaving cross-ratios intact. Therefore the function assigning cross-ratios to quadruples of points on the circle does not determine the function assigning distances between them. In that sense one can say that the cross-ratio function amounts to less structure than the metric but more than the topology. Michael Hardy (talk) 23:41, 26 June 2015 (UTC)

(Late response to original post.) To play devil's advocate: If RP^1 is a circle, then what is the radius of the circle? The average reader of Wikipedia thinks that circles have radii. They do not implicitly understand that you have omitted the words "smooth manifold diffeomorphic to". The one-point compactification construction suggests that the radius is infinite. The fact that the unit circle in R^2 double-covers RP^1 suggests that its radius is 1 / 2.

The average reader is not familiar with notions of space that lack notions of distance. And do we expect such readers to read this article? Or should this article expect that the reader is coming from some background in topology, algebraic geometry, etc.? Mgnbar (talk) 00:20, 27 June 2015 (UTC)

To put it another way: If RP^1 is just a circle, then why does it have any special name at all? (I have been asked such questions about Riemann spheres being "just" spheres.) Mgnbar (talk) 00:27, 27 June 2015 (UTC)

@Michael Hardy:@Mgnbar: There is a natural metric on the real projective line and it is the same as the metric of a circle with radius one-half. I explained this on the talk page. About why $\mathbb {R} P^{1}$ has a name, it assuredly wouldn't, were it not for $\mathbb {R} P^{n}$ - in fact I am having trouble finding sources that even talk about it in any detail, presumably because it is just a circle. --Sammy1339 (talk) 01:57, 27 June 2015 (UTC)

It is not "just" a circle. Topologically it is a circle, but it may differ in some other respects from what is normally called a circle. Michael Hardy (talk) 04:01, 27 June 2015 (UTC)

Under your metric, the real line does not isometrically embed into RP^1. So readers may be confused by statements about how RP^1 is just the real line with one point at infinity added. That's the point. There are several ways to think about projective spaces. Mgnbar (talk) 03:30, 27 June 2015 (UTC)

The euclidean real line cannot be isometrically imbedded in $\mathbb {R} P^{1}$. --Sammy1339 (talk) 03:56, 27 June 2015 (UTC)

I think that our disagreement comes from different viewpoints, which exist because RP^1 appears in various areas of mathematics. Your viewpoint seems to be differential geometry. I mentioned the real line because its topological embedding into RP^1 is an important example in topology (the one-point compactification). Your talk of metrics and circles seems beside the point to me, because in elementary algebraic geometry, which uses projective spaces heavily, there is often no mention of circles and metrics.

So maybe we should stick to precise (and verifiable) statements about how RP^1 is topologically a circle, can be endowed with a metric under which it is isometric to a Euclidean plane circle with radius 1/2, etc.? Mgnbar (talk) 12:35, 27 June 2015 (UTC)

I would also like to suggest that at some point someone makes an attempt to find sources supporting their position, rather than relying on appeals to pure reason only. (And that is the last from me, probably.) --JBL (talk) 01:15, 27 June 2015 (UTC)

@Joel B. Lewis: Yes, I share that concern. But we also have to use common sense and write the article in a way laypeople can understand. We're supposed to paraphrase sources, not copy from them. I am bothered by some of the uncited claims in the article though, particularly the stuff about the "automorphism group." --Sammy1339 (talk) 01:57, 27 June 2015 (UTC)

Yes, sources determine what we can and cannot write here. But keep in mind that different sources may use terms such as "circle" differently. In fact, a topology textbook and a geometry textbook may disagree on what that term means. And maybe neither of those books is written for this article's audience. Mgnbar (talk) 03:30, 27 June 2015 (UTC)

Contrary to what was indicated by Sammy above, the universal cover of $\mathbb {R} P^{1}$ and of $S^{1}$ (which are the same thing) is $\mathbb {R}$. Remember that a universal cover must be simply connected. JRSpriggs (talk) 11:00, 28 June 2015 (UTC)

Jul 2015

Jacobian conjecture

One or more math editors are needed to deal with suggestions I posted to the talk: Jacobian conjecture page. If you need to contact me, please use email, as I have difficulties navigating to my user talk page. — Preceding unsigned comment added by L.Andrew Campbell (talk • contribs) 00:40, 3 July 2015 (UTC)

uncorrelated random variables

I just moved uncorrelated to uncorrelated random variables. Normally that would cause the new title to appear in the new articles list tomorrow. But it won't unless someone finally rescues Jitse' bot. Michael Hardy (talk) 19:07, 3 July 2015 (UTC)

AfC submission

Is Draft:Hierarchical testing of variables in high dimensional datasets notable? Best, FoCuSandLeArN (talk) 20:30, 3 July 2015 (UTC)

Need a math person with some hard copy texts

I am trying to track down and alleged copyright violation. A reader wrote to the Wikimedia foundation noting that the text of the following article: Cyclic decomposition theorem is a copy of the source material:

• Hoffman, Kenneth; Kunze, Ray (1971). Linear algebra (2nd ed.). Englewood Cliffs, N.J.: Prentice-Hall, Inc. p. 231

Our usual copyright tools failed to identify a problem because they tend to work with online materials. I tried invoking one tool which has access to off-line academic material but that failed to identify a problem. I don't believe the reader is making it up but I need some confirmation before I can remove it. I'm hoping that there is some reader of this wiki project who happens to have a copy of the text handy and can check it out.--S Philbrick(Talk) 15:05, 4 July 2015 (UTC)

The theorem statement is a word-for-word copy of the one appearing in the source. The editor who added the material in question is correct that inevitable there will be some overlap in any two statements of the same theorem, but an exact match cannot have been a mere coincidence. I believe that this does qualify as a copyvio from the rather stringent conditions of Wikipedia. The article should be deleted, and replaced with an untainted version. Sławomir Biały (talk) 15:41, 4 July 2015 (UTC)

Thanks for the response, now deleted. (and a candidate for a new article, if someone is looking for something to do :)--S Philbrick(Talk) 17:16, 4 July 2015 (UTC)

Is Jitse's bot dead forever?

Jitse's bot hasn't updated the new articles list in almost two weeks. Four days ago I sent Jitse Niesen an email and I haven't heard anything. Will Wikipedia be forever dependent on one person in that way? How should we proceed? Michael Hardy (talk) 23:27, 26 June 2015 (UTC)

Actually I responded at the very top section #No_new_articles several days ago and got no response. I will try again here. What does it take to run the bot? Does it run on the wikimedia foundation's server? I found this page [25] but I'm not sure if is related. As for a long-term plan, I agree it would make sense if someone else can take over running the bot (it should be so much easier to taking over the task than starting over), as apparently Jitse is no longer active. -- Taku (talk) 00:17, 29 June 2015 (UTC)

I've raised it here: Wikipedia:Bot_owners' noticeboard#Jietse's bot.--JohnBlackburne^words_deeds 18:55, 3 July 2015 (UTC)

I think Jitse Niesen will probably look at this within 48 hours. Michael Hardy (talk) 03:59, 9 July 2015 (UTC)

Jacobian conjecture Please Help

I really need some help from experienced math editors. I posted some suggestions to the talk:Jacobian conjecture page on June 23, designed to correct some basic mathematical flaws in the article. I am a genuine expert on the subject but I am now blind and totally inexperienced with Wikipedia. So others need to carry out the actual edits. The suggestions don't correct everything in the article, but make a good start. Someone must know how to bring this to the attention of previous editors of the page.Please use email to contact me if desired.

L.Andrew Campbell (talk) 00:53, 9 July 2015 (UTC)

It looks to me like some of those suggestions have already been implemented by User:R.e.b. several days before this post. In fact, unless I'm mistaken, all of your suggestions were promptly implemented. I'm more than happy to help, but could you please be clearer what still needs to be done? Sławomir Biały (talk) 13:26, 9 July 2015 (UTC)

Sławomir Biały, I think that L.Andrew Campbell probably has difficulty reading this page. I was thinking of sending your message to him as an e-mail, but I would only do that if you haven't done so already. Have you? --JBL (talk) 14:48, 9 July 2015 (UTC)

No, I haven't. Sławomir Biały (talk) 22:42, 9 July 2015 (UTC)

Just saw those changes, thanks. I will try to make further changes myself.

L.Andrew Campbell (talk) 23:31, 9 July 2015 (UTC)

Draft:Thaine's theorem - references available if someone knowledgeable can apply them

Dear mathematicians: There appear to be quite a few book references that could be added to make this stub into an article, for example [26], [27] and [28], but I don't know how to apply them. Can someone help? —Anne Delong (talk) 01:28, 9 July 2015 (UTC)

Why not simply add these to the stub and push it out into main space? If someone is interested, then the article will expand in the natural Wiki fashion. Sławomir Biały (talk) 13:42, 9 July 2015 (UTC)

Sławomir Biały, It seems that R.e.b. has done just that. Thanks to you both. —Anne Delong (talk) 13:25, 10 July 2015 (UTC)

E (mathematical constant)

Two separate editors have requested some outside input at Talk:E (mathematical constant). See Talk:E (mathematical constant)#287,000 digits in 1988 and 1,000,000 in 1992 concerning a question of whether we should cite someone's self-published and unpublished computer programs (including a rather novel interpretation of WP:SPS), and Talk:E (mathematical constant)#Exponential-like functions concerning whether original research is permitted. Sławomir Biały (talk) 12:55, 9 July 2015 (UTC)

Other Wikipedia math experts please comment. Rather than continue discussion on the talk page he sites above, Slawomir took it upon himself on the same day he posted the comment above (9 July 2015) to delete much of the table of "Known Digits" at E (mathematical_constant)#Known_digits and substitute "Since that time, the proliferation of modern high-speed desktop computers has made it possible for amateurs to compute billions of digits of e". Please look at what he deleted. He is totally missing the documented and referenced and very important algorithmic advances that made those increased approximations possible. His page change comment is "WP:SPS is pretty clear that we shouldn't have these entries..." when that was the very thing being discussed with me at Talk:E (mathematical constant)#287,000 digits in 1988 and 1,000,000 in 1992. He just decided he was right and stopped the discussion by deleting much of the table. He also says "There are no recognized authorities for world record computations [of e], unlike pi" without siting what those pi authorities are or why the history of pi precision at Pi#Modern_quest_for_more_digits is included in Wikipedia but the page on e somehow doesn't warrant such information. Also in Talk:E (mathematical constant)#287,000 digits in 1988 and 1,000,000 in 1992 he comments "Anyone with a computer can compute billions of digits of e, as the case of Alexander Yee shows." Again, he is minimizing and missing the algorithmic advances by mathematicians and computer scientists (such as myself) who spent significant time and effort advancing the state of the art using extended-precision approximations of e as an example problem. Someone with the authority, please correct him and undo his changes or explain the inconsistencies between the pi and e articles in such a way that makes it obvious why such different standards should be applied to the two. Thank you. Rick314 (talk) 04:43, 10 July 2015 (UTC)

From the article "The number of known digits of e has increased substantially during the last decades. This is due both to the increased performance of computers and to algorithmic improvements." Two references are given. If you feel that details of the algorithmic improvements have been omitted, you are welcome to supply additional references to reliable secondary sources.

The reason there is a difference between π and e here is that there are many reliable secondary sources concerning the quest for more digits of pi. For example, Arndt and Haenel spend a chapter discussing it. Papers in "Mathematics of computation" and "The American Mathematics Monthly" discuss new algorithms for computing π. Indeed, Borwein and Borwein have and entire book on this subject. As far as I am aware, no such sources exists concerning the computation of e, although I have requested such sources, as they would certainly be most welcome if they existed. On the contrary, the portion of the table I removed was sourced to usenet posts and unpublished emails. Those are simply not acceptable sources, at either article. So there aren't "different standards ... applied to the two", rather I have applied the same strict standards of sourcing to the one article as the other.

In fact, I have given the e article slightly the benefit of the doubt by including two references to Gourdon concerning "algorithmic advances". Since you believe that I have "missed the algorithmic advances", now would be a good time to correct me by supplying sources to the secondary literature (peer reviewed journals, books, etc.) that discuss these advances.

Finally, regarding the rather childish observation that you made "He just decided he was right and stopped the discussion by deleting much of the table", in this post, you agreed that "Existing references already violate [our guidelines]." I agreed with this statement, and removed the portion of the table that did not agree with our guidelines. My edit summary clearly referenced the guideline that they violate, and I also referred in that discussion to policy reasons why Wikipedia should not be in the business of record-keeping on the authority of Usenet posts and unpublished emails. I would have thought that was clear. There was evident consensus that these entries did not meet the requirements set forth at those policies and guidelines. Your arguments did nothing to contradict that conclusion. Indeed, one of your arguments is "Look at my documentation referenced in this discussion above. It is actually better than several already existing table references and I have emails that confirm third-party (not me) verification of my results." Yes, that's true. But the other results were poorly-referenced as well. Surely it is not very surprising that the outcome would be their removal, rather than the inclusion of your own results in the table, given our apparent agreement that the references used in the table are unsuitable? Sławomir Biały (talk) 13:37, 10 July 2015 (UTC)

I agree with Rick314 that it was rather poor form for Sławomir Biały to go make this edit in the middle of a discussion. But on substance I think Sławomir Biały is correct, for exactly the reasons he has given. --JBL (talk) 13:53, 10 July 2015 (UTC)

Well, Rick314 had already announced his intention to make an edit, against consensus, guidelines and policies. There was a very clear consensus at the discussion page that the table entries were inappropriate. The discussion was ongoing for several weeks, during which time anyone at all could have weighed in. If we waited indefinitely for such discussions to be "done", nothing would ever happen on Wikipedia, and we would be stuck in endless discussions with COI/SPAs. So I disagree very strongly that it was,"poor form". This is just an articulation of WP:BOLD, which is policy. Sławomir Biały (talk) 15:04, 10 July 2015 (UTC)

Sorry, but this is a ridiculous number of words and policies to spout on a question of basic politeness and consensus-building. If you're discussing changes with someone and haven't reached consensus, it's rude to go and impose your version while discussion is ongoing. There was no particular rush, and there had been no third opinion yet. You acted a bit like a jerk, unnecessarily. The world would have been a very slightly better place if you hadn't done so. That is all. --JBL (talk) 15:14, 10 July 2015 (UTC)

Excuse me, but I really think thus criticism of my behavior is way out of line, and I think you should apologize. As far as I can tell, I'm the only editor at E (mathematical constant) who is urging against a series of ill-considered edits that go against policoes. I feel that the community has been negligent here. I shouldn't be the only one needing to comment there. I know this is a well-watched page. So where was everybody else? How come I was the only one holding the bag there? Twould weeks went by, and made an edit, with clear reasons behind it. By any standards, those are reasonable actions. And calling other people names also isn't likely to make the world a better place. Sławomir Biały (talk) 15:56, 10 July 2015 (UTC)

Notice after Slawomir's edit the article reads "...the proliferation of modern high-speed desktop computers has made it possible for amateurs to compute billions of digits of e." There is no mention of algorithmic improvements there. It refers to Alexander Yee as an example amateur. (He is not.) Similarly, amateur me improved expert Steve Wozniaks's algorithm 4 ways as explained on the first 2 pages of my 1992 source code. So no apology from me, and both Slawomir's process and content are inappropriate. "Expert" and "amateur" are subjective terms to be avoided, and I think intentionally used in the article by Slawomir as an insult. Let's stick to Wikipedia publishing guidelines. As I read WP:SPS and WP:ABOUTSELF (look at the details) the original table entries seem fine. Regarding books, does e: The Story of a Number (Princeton Science Library) move e and pi closer together in terms of leaving a history of precision improvements? The Table of Contents is available at that link, but I am not sure what content makes it more or less applicable to this discussion. — Preceding unsigned comment added by Rick314 (talk • contribs) 17:22, 10 July 2015 (UTC)

There is no mention of algorithmic improvements there. This is wrong. From the article: "The number of known digits of e has increased substantially during the last decades. This is due both to the increased performance of computers and to algorithmic improvements." I said as much above, and requested additional citations. References to the literature are welcome. Tendentious lies like this are not constructive, and could potentially result in having your editing privileges revoked.

Regarding "amateurs", Yee's own website refers to this as a high school project. It's hard to defend your view that he was acting in a professional capacity as a mathematician.

We already reference "e - the story of a number". And, in fact, according to that source, which contains almost no discussion of records, "In one sense the stories of e and π differ. Because of the longer history and greater fame of π, the urge to compute it to an ever greater number of digits over the years has become something of a race... No such craze befell e." So, if anything, this source actually supports the opposite stance.

You're just wrong about WP:SPS. That policy states "self-published media, such as books, patents, newsletters, personal websites, open wikis, personal or group blogs (as distinguished from newsblogs, above), Internet forum postings, and tweets, are largely not acceptable as sources." The weird interpretation of the policy that it's ok to use self-published sources in scientific articles as long as one is discussing one's own accomplishments falls well outside of any reasonable reading of it, especially taken in conjunction with the rest of our policies.

Finally, you have a clear conflict of interests insisting that the article must cite your own unpublished work. This makes it essentially pointless to attempt discussion, since you are clearly using a very self-serving reading of policies, guidelines, discussions, and the article. For example, you apparently cannot be bothered to notice that the article does mention algorithmic improvements, even after it has been pointed out to you!

The bottom line is, we are absolutely not going to cite your usenet posts and unpublished work. If you have a paper that is published in a peer reviewed place (typical of professional, as opposed to amateur, mathematicians), then please give a reference to that. Otherwise, I don't see further discussion as remotely constructive. Sławomir Biały (talk) 18:03, 10 July 2015 (UTC)

My initial reaction was the same as JBL's but I in no way disagree with Slawekb's edit. Coming to the discussion late and reading the whole thing at once gave the impression that the edit was rash, but I now realize that the time element (this discussion had been going on for weeks) was missing. I was about to make the same edit and upon finding out that it had already been done my initial reaction was just re-enforced. Perhaps it would have been better if another editor had done it, but as Sławomir has pointed out, we (collectively) were late to the game and dropped the ball on this one. As to the substance of Rick314's objections, I find no merit in the argument and see this as falling squarely under the umbrella of WP:OR. If Rick314 publishes his results and an unrelated third party writes about them then we can include a discussion of them by sourcing the third party. Although many do chaff under these restrictions, they are necessary to prevent WP from devolving into yet another internet bulletin board. There are many breaches of these guidelines to be found in our articles, and when we come across them we need to act decisively, as Sławomir has done. Bill Cherowitzo (talk) 18:22, 10 July 2015 (UTC)

Thank you Bill. You said "If Rick314 publishes his results and an unrelated third party writes about them then we can include a discussion of them by sourcing the third party." I asked about this way way back in the article Talk. My dated algorithm documentation and source code and execution metrics and more are now published in Wikimedia Commons. I can put them somewhere else if appropriate. I have emails with a third party and they checked everything there. My reviewer could have entered a row for my 1988 and 1992 records? (Slawomir please stop repeating your position and I will too. I hope we can get input from others and the amount of text here is unwieldy.) Rick314 (talk) 01:23, 11 July 2015 (UTC)

I think you misunderstood something. In this context, "publishes" means to publish in a way that makes something a reliable source, e.g. by going through peer review and getting it published in an academic journal. It doesn't mean merely making something available online. —David Eppstein (talk) 03:04, 11 July 2015 (UTC)

Sorry that I did not make myself clear. When I say published, I mean published in a peer reviewed venue and not any form of self publication and the same holds for the third party source. Notice that no one here has criticized your work or even hinted that it might be incorrect, in fact I am working under the assumption that it is perfectly fine – the objections have to do with how statements that appear on WP are backed up "in the literature". The editors of WP are not to be the judges of the content, they can only report on what the reliable secondary sources say about that content. If there are no such sources, then we do not say anything and don't include the content! Bill Cherowitzo (talk) 03:17, 11 July 2015 (UTC)

OK, and thanks for all your help and explanations. I better understand Wikipedia content rules now. Rick314 (talk) 18:10, 11 July 2015 (UTC)

Correlation coefficient

Can someone convert this disambiguation page into an article explaining the general concept of a correlation coefficient, and how all the types on the page fall into this concept? Cheers! bd2412 T 14:13, 13 July 2015 (UTC)

Does correlation and dependence help ? Gandalf61 (talk) 14:57, 13 July 2015 (UTC)

It's already a link on the page. Correct me if I'm wrong, but I presume that a correlation coefficient is merely a coefficient that illustrates correlation (in the correlation and dependence sense)? bd2412 T 15:25, 13 July 2015 (UTC)

Yes, that's right - it is a quantitative measure of correlation (of some type). Gandalf61 (talk) 15:43, 13 July 2015 (UTC)

Ok, that will do. Thanks! bd2412 T 16:12, 13 July 2015 (UTC)

Rayleigh II

I disambiguated "Rayleigh II" at Wave field synthesis to point to Rayleigh–Jeans law, but now I'm not so sure if that is correct. I find references to a Rayleigh I, Rayleigh II, and Rayleigh III equations (See, e.g., Ahmet Kondoz, ‎Tasos Dagiuklas, Novel 3D Media Technologies (2014), p. 213, noting the use of the Rayleigh I and Rayleigh II equations for plotting wave scattering), which fit topically but differ in the equations used. What is the right answer here? bd2412 T 17:37, 15 July 2015 (UTC)

OR in progress at Thomas precession

Folks, those with an interest in relativity, please take a look at what I believe is unjustifiable, unsourced OR in progress at Thomas precession. Look at [this claim], for example. —Quondum 17:39, 12 July 2015 (UTC)

Isn't this is an overreaction? YohanN7 and myself have been creating diagrams for Thomas precession which do appear in a few papers by at least two authors. We are filling in the gaps where these papers are unclear, so by WP:CALC it should be allowed. M∧Ŝc²ħεИ_τlk 18:08, 12 July 2015 (UTC)

For clarity... YohanN7 has, as always, provided painfully detailed explanations and Quondum walked off, because "bully boy" YohanN7 was being too "energetic".

When the diagrams were created, Quondum provided no source, nor reference, nor even his own worded description, supporting his claim that Lorentz boosts in any direction do not preserve orthogonality of the spatial axes, he just accused YohanN7 of "unsourced" WP:OR and took the report here. I blindly (as always) assumed I was wrong and others are correct, and thought I knew where Quondum came from and only blundered, about the LT matrix for a boost in any direction (no longer on Talk:Thomas precession, see its history if you care). Quondum has also claimed we were "not giving room to speak", which is clearly false because he has and no-one stopped him.

Another reference supporting orthogonality under Lorentz transformations (rotation and boost) is Goldstein, 2nd edition, page 285. M∧Ŝc²ħεИ_τlk 16:34, 16 July 2015 (UTC)

Reply

File:Cushing Excerpt.JPG

Excerpt from ref Vector Lorentz transformations by James T. Cushing.

Since I have been reported for allegedly doing original research on a talk page, I feel I have to be my own lawyer and defend myself. I do thank Maschen for some moral support, here, and there.

First off, everything is in order because Quondum's claim's about unsourced original research are false. Two of the sources are presented below. Normally Cushing should more than suffice, but since weight is needed versus authority, I added Weinberg as well, almost notorious for not making mistakes, both here and in the article.

To the right there is also an excerpt from Cushing's paper that verbatim verifies the disputed passage and diagrams in the article, and also my post on the talk page for which I am being reported.

At least in theory, it is thus a possibility that Quondum is incorrect in real life. But this matters little. He is most certainly wiki-incorrect, because my statement is verifiable. According to Wikipedia policy, verifiability weighs more than truth.

Quondum's allegation that it is unjustifiable is possibly true. We can, as is done in most (actually all) of the relevant literature, toss the whole issue off as being obvious. That would save valuable space in the article. But , alas, Quondum wouldn't have that to begin with, so, we have to go through this in depth in the article.

• Cushing, J. T. (1967). "Vector Lorentz Transformations". Am. J. Phys. 35. AAPT: 858–862. doi:10.1119/1.1974267. {{cite journal}}: Invalid |ref=harv (help); Unknown parameter |subscription= ignored (|url-access= suggested) (help)
• Weinberg, S. (2002), The Quantum Theory of Fields, vol. 1, Cambridge University Press, pp. 68–69, ISBN 0-521-55001-7

Original research

So that wasn't original research, whether unsourced or unjustifiable. But this is! Let

${\mathfrak {so}}(3,1)={\mathfrak {so}}(3)\subset {\mathfrak {so}}(3,1)\oplus {\mathfrak {k}},$

vector space direct sum. Let ξ ∈ k be an arbitrary boost parameter. Then e^{ξ ⋅ K} is, by definition, an arbitrary pure boost. Claim: For any rotation parameter ς,

$T=e^{-{\boldsymbol {\zeta }}\cdot \mathbf {J} }e^{{\boldsymbol {\xi }}\cdot \mathbf {K} }e^{{\boldsymbol {\zeta }}\cdot \mathbf {J} }=e^{e^{-{\boldsymbol {\zeta }}\cdot \mathbf {J} }({\boldsymbol {\xi }}\cdot \mathbf {K} )e^{{\boldsymbol {\zeta }}\cdot \mathbf {J} }}$

is a pure boost (equality is by property of the matrix exponential). By a property of Ad,

$e^{-{\boldsymbol {\zeta }}\cdot \mathbf {J} }({\boldsymbol {\xi }}\cdot \mathbf {K} )e^{{\boldsymbol {\zeta }}\cdot \mathbf {J} }\in {\mathfrak {so}}(3,1).$

By the relationship between Ad and ad,

$e^{-{\boldsymbol {\zeta }}\cdot \mathbf {J} }({\boldsymbol {\xi }}\cdot \mathbf {K} )e^{{\boldsymbol {\zeta }}\cdot \mathbf {J} }=e^{\mathrm {ad} _{-{\boldsymbol {\zeta }}\cdot \mathbf {J} }}{\boldsymbol {\xi }}\cdot \mathbf {K} .$

But

$[-{\boldsymbol {\zeta }}\cdot \mathbf {J} ,{\boldsymbol {\chi }}\cdot \mathbf {K} ]\in \mathbf {k} ,$

for arbitrary χ, so (recalling ad_Zⁿ(W) works by composition)

$e^{-{\boldsymbol {\zeta }}\cdot \mathbf {J} }({\boldsymbol {\xi }}\cdot \mathbf {K} )e^{{\boldsymbol {\zeta }}\cdot \mathbf {J} }=e^{\mathrm {ad} _{-{\boldsymbol {\zeta }}\cdot \mathbf {J} }}{\boldsymbol {\xi }}\cdot \mathbf {K} \in \mathbf {k} .$

Hence

$T=e^{e^{-{\boldsymbol {\zeta }}\cdot \mathbf {J} }({\boldsymbol {\xi }}\cdot \mathbf {K} )e^{{\boldsymbol {\zeta }}\cdot \mathbf {J} }}=e^{-{\boldsymbol {\zeta }}\cdot \mathbf {J} }e^{{\boldsymbol {\xi }}\cdot \mathbf {K} }e^{{\boldsymbol {\zeta }}\cdot \mathbf {J} }$

is a pure boost, again by definition. Since exp is onto both SO(3) and SO⁺(3,1), and since the action of SO(3) on a sphere is transitive, the claim in the by Quondum disputed [edit] is proved (once the remaining easy details left to the reader are filled in).

If one follows the action of the successive transformations on the spatial coordinate axes, it is apparent what is going on. Rotate, then stretch the z-axis, Oops, this is wrong, the boost is active leaving all coordinate axes alone boost (leaving coordinate axes intact), then rotate back.

The interpretation is not unsourced original research, see Cushing above and A. Ben-Menahem (1985) (ref in article) for stretching by γ For strikeout, see above small comment. Since references are scanty on proofs, I might, by WP:CALC, put this in a footnote in the article, unless someone spots an error. YohanN7 (talk) 17:03, 13 July 2015 (UTC)

Tricki

I was just looking around Tricki at [29] and thinking how it serves a purpose almost completely orthogonal to Wikipedia in helping with how things are done. I was wondering if there wasn't some way of getting a bit of synergy somehow where we continue along the current paths but people can easily find a way over to Tricki from the reference desk for instance. It doesn't fit in with Wikipedia's content policies and I can't see an easy way of doing anything with it but it seems a shame not to have a way of guiding people who ask questions to a place that helps them with how to solve a problem. Dmcq (talk) 10:20, 15 July 2015 (UTC)

Probably a first step would be to have a WP article on it other than just a redirect to Timothy Gowers. Maybe a second step would be to jut start linking WP articles to Tricki where appropriate. For reference desk questions there's no reason you can't supplement an answer with a link to Tricki if it would help; there are a couple of occasions where a question was answered with a link to math.stackexchange.com or mathoverflow.net. I browsed an article, [30] on Gowers's weblog on the future of Tricki and he was saying that he started Tricki before these sites had taken off, and they have taken away a lot of the potential online math market. But to extend your analogy, I think the space has enough dimensions for quite a few mutually orthogonal directions. Another relatively recent development is the appearance of online lectures and screencasts. A role WP could play in this is as a kind of switchboard to these other resources. I'm not certain that the "External links" format we have now is up to the task though. When WP first started there were maybe a few other websites on specific topics, but nowadays you can take an entire lecture course (sans final exam), find a selection of textbooks for it and even get help with questions, all online and often free. --RDBury (talk) 17:45, 16 July 2015 (UTC)

Sine

Sine is undergoing an AfD suggesting that it should be merged back into Trigonometric_functions#Sine, cosine and tangent. Please participate at Wikipedia:Articles for deletion/Sine. —David Eppstein (talk) 00:35, 18 July 2015 (UTC)

Also, there's a fairly new deletion sorting page, Wikipedia:WikiProject Deletion sorting/Mathematics, that you might find it useful to watch and/or check regularly, since that's where things like this should eventually appear. —David Eppstein (talk) 07:39, 18 July 2015 (UTC)

Request for Comment

Comments would be appreciated on this RfC: Talk:Infinite_monkey_theorem#RfC:_Which_of_these_versions_of_the_lead_is_the_more_accurate_and_informative.3F. Thanks DaveApter (talk) 10:29, 20 July 2015 (UTC)

Independence and its negation

(Z \perp\!\!\!\perp Y)_{G_{\overline{X}}} \qquad(Z \not{\perp\!\!\!\perp} X)_G

$(Z\perp \!\!\!\perp Y)_{G_{\overline {X}}}\qquad (Z\not {\perp \!\!\!\perp }X)_{G}$

How can we get this negation to look better? Michael Hardy (talk) 00:38, 19 July 2015 (UTC)

Even more negative space?

(Z \perp\!\!\!\perp Y)_{G_{\overline{X}}} \qquad(Z \not\!\!{\perp\!\!\!\perp} X)_G

$(Z\perp \!\!\!\perp Y)_{G_{\overline {X}}}\qquad (Z\not \!\!{\perp \!\!\!\perp }X)_{G}$

(As discussed here.) I would suggest doing it in wikiformatting using the double up tack unicode character instead (⫫) but getting that to work well with a double-subscript-overbar is unlikely, not to mention that amazingly unicode seems to be missing the negated double up tack symbol. —David Eppstein (talk) 01:28, 19 July 2015 (UTC)

Is such symbol in use (anywhere except, maybe, wikipedia)? I never saw it (as well as negated orthogonality, etc). Moreover, my experience with some economists shows that they tend to misunderstood the meaning of "not independent", mostly as "either positively dependent or negatively dependent" or something like this. The exact meaning of this negation seems to be clear only to mathematicians; but these do not need such notion (I think so). Boris Tsirelson (talk) 04:25, 19 July 2015 (UTC)

I've seen this symbol used for probabilistic independence used in other places. Michael Hardy (talk) 21:19, 20 July 2015 (UTC)

That double up tack unicode character doesn't display for us with old computers. YohanN7 (talk) 11:29, 19 July 2015 (UTC)

I would do it with a few more slash-bangs, as David suggests. Also, I would probably use the built-in symbol \amalg ($\amalg$) instead of hacking TeX to produce such a symbol out of other ones. Sławomir Biały (talk) 12:22, 19 July 2015 (UTC)

\not\amalg ($\not \amalg$) actually works without spacing hacks, but unfortunately that's the wrong symbol: conditional independence uses the double up tack. —David Eppstein (talk) 16:12, 19 July 2015 (UTC)

I've implemented David Eppstein's solution at Instrumental variable. Michael Hardy (talk) 21:18, 20 July 2015 (UTC)

Ratios always dimensionless?

Pls weigh in: Talk:Ratio#Split mathematics. Fgnievinski (talk) 05:49, 22 July 2015 (UTC)

Perennial upright d

The perennial upright d issue has been raised once more at WT:MOSMATH. Opinions are welcome. Sławomir Biały (talk) 17:02, 24 July 2015 (UTC)

Jacobian conjecture results

I have posted suggestive changes with the above title to the JC talk page. An experienced math editor is needed. As a wrinkle, they include use of the name Druzkowski, which needs a dot over the letter z. Thanks,

L.Andrew Campbell (talk) 23:03, 24 July 2015 (UTC)

Anomalous MathJax rendering.

In Variance, some code said this:

\sigma_y^2 \le 2y_\text{max} (A - H)

I changed it to this:

\sigma_y^2 \le 2y_\max (A - H)

Strangely, this had the effect of causing BOTH "max" and the left parenthesis to appear in subscript. So I changed it to this:

\sigma_y^2 \le 2y_{\max} (A - H)

That's how it stands now. Let's try it both ways and see how it looks here:

$\sigma _{y}^{2}\leq 2y_{\max(}A-H),$

$\sigma _{y}^{2}\leq 2y_{\max }(A-H),$

Just a bug, or is there some sensible reason for this? Michael Hardy (talk) 20:25, 24 July 2015 (UTC)

I think the basic principle is that some or most of our math rendering pathways are not actually based on Knuth's TeX code and have occasional differences in parsing because of it, that can usually be fixed with more braces. —David Eppstein (talk) 20:57, 24 July 2015 (UTC)

I've use \max as a subscript with no braces in Wikipedia articles thousandds of times over quite a few years without seeing this problem. Will it suddenly be necessary to change all of them because of some change that just happened in the software? Michael Hardy (talk) 07:11, 25 July 2015 (UTC)

It seems like almost correct behaviour. \max is a maths operator which expects the next character as an argument. ( is the next character so that is taken as the argument. Running the the code through standard LaTeX produces an error and won't compile at all. It does not look like its new behaviour as you get the lower bracket in PNG, and MathJax. --Salix alba (talk): 08:59, 25 July 2015 (UTC)

It looks like the problem only happens when the next character is a bracket, so most case are OK. I've run a search for equations with the bug and fixed the ten or so pages where it occurs.--Salix alba (talk): 11:20, 25 July 2015 (UTC)

Would it be possible to find every case where \max occurs in a subscript or superscript to change it to {\max}, maybe even without needing to do each one by hand? And \min too. Michael Hardy (talk) 19:48, 25 July 2015 (UTC)

Uniform convergence

A new user Sergey Liflandsky is adding proofs to the "Uniform convergence". Neither mathematics nor English are free of errors. But more important is the question, do we need these proofs at all? Boris Tsirelson (talk) 11:00, 26 July 2015 (UTC)

I don't think the proofs are an improvement. Generally speaking, it's acceptable for Wikipedia articles to summarize proofs, but not to give detailed proofs of statements. In the article under discussion, the proof is already summarized as the ε/3 trick. Filling in the details is routine. To readers for whom it is not routine, then WP:NOTTEXTBOOK applies. Detailed proofs are the sort of thing one looks for in textbooks, not encyclopedia articles. Sławomir Biały (talk) 11:19, 26 July 2015 (UTC)

I see the same editor has added a proof to Weierstrass M-test. This is a little more justifiable I think, because there was a proof already there and the new proof is somewhat more straightforward than the old one. Ideally, both proofs should be shortened and summarized. In fact, the new proof can more or less be reduced to a sentence or two. Something like: "Because the sequence of functions is uniformly bounded in absolute value by a summable sequence of numbers $M_{n}$, the difference between two partial sums of the series of functions is bounded by the difference between two partial sums of the series $\sum M_{n}$. So the Cauchy criterion implies that the series of functions converges." Sławomir Biały (talk) 11:31, 26 July 2015 (UTC)

Also Ratio test#Proof of Kummer's Test. Boris Tsirelson (talk) 11:52, 26 July 2015 (UTC)

I don't object to that one. The test is rather baffling without a proof. Sławomir Biały (talk) 13:11, 26 July 2015 (UTC)

I got rid of the proof that Riemann integration commutes with uniform limits. This is geometrically obvious, and the given proof was very unenlightening. Sławomir Biały (talk) 12:38, 26 July 2015 (UTC)

It is also possible that some proofs are notable by themselves. I even wrote an article once because I thought the proof of something (at least in one direction) was extremely nifty. YohanN7 (talk) 14:52, 27 July 2015 (UTC)

Naming convention for Parenthetical disambiguation

At hypercycle (geometry) which I renamed to hypercycle (hyperbolic geometry) there is been some discussion about "Parenthetical disambiguation" and we would like to have that discussion in a more general place (here).

The facts (add when needed) :

• There is a need to have a parenthetical disambiguation:

There are two meanings of Hypercycle, one hypercycle (chemistry) and a mathematical one that is only used in hyperbolic geometry neither one should be the primary subject for Hypercycle

• wp:DAB: If there are several possible choices for parenthetical disambiguation, use the same disambiguating phrase already commonly used for other topics within the same class and context, if any. Otherwise, choose whichever is simpler. (no more specific guidance exist)

So what is the best parenthetical disambiguated name for this page? The options are (add when there are more):

• hypercycle (mathematics)
• hypercycle (geometry)
• hypercycle (hyperbolic geometry)

Why hypercycle (geometry)?

• Historical, the article was named this way previously
• Shortest parenthetical disambiguation name

Why hypercycle (hyperbolic geometry)?

• The subject (as described in the article ) is rather sopecialised and only used in hyperbolic geometry and I think the most precise parenthetical disambiguation is best. WillemienH (talk) 05:57, 27 July 2015 (UTC)

Why hypercycle (mathematics)?

(no reasons yet) , but is this not what wp:DAB prescribes?

Please join in WillemienH (talk) 05:57, 27 July 2015 (UTC) (ps I prefer hypercycle (hyperbolic geometry) )

Your choice of "(hyperbolic geometry)" violates the "whichever is simpler" part of the guidance you quote, so I don't think it is a good choice. I don't have a strong preference between the other two, but I tend to prefer "(geometry)", in part because we already have plenty of geometry disambiguators and in part because it was the one that was already used. —David Eppstein (talk) 06:39, 27 July 2015 (UTC)

I agree with David and others that "(hyperbolic geometry)" is unnecessary complicate, as it does not help readers in their choice. On the other hand, my opinion is that "(mathematics)" must also be avoided in this case. In fact, I am not sure that "hypercycle" is not used in other parts of mathematics. In any case, as "cycle" is used with various meanings, in particular in graph theory and topological algebra, it is useful to inform the reader that "hypercycle" is not a generalization of such cycles. Therefore my opinion is that the move done by WillemienH must be reverted. D.Lazard (talk) 09:25, 27 July 2015 (UTC)

There are certainly papers that study differential equations or dynamical systems intended to model the chemical kind of hypercycle. There are also papers about hypergraphs that call certain structures in them hypercycles. So yes, "mathematics" seems too ambiguous and this gives another reason to stick with "geometry". —David Eppstein (talk) 23:46, 27 July 2015 (UTC)

My understanding is that the purpose of parenthetical disambiguation is primarily for typing into the search box. As such, shorter is almost always better. I think hypercycle (geometry) is best. Sławomir Biały (talk) 12:14, 27 July 2015 (UTC)

Help on disambiguating "matrix models" needed

Hello, math people! Me and i think most other wikipedians who are focusing on eliminating ambiguous links in Wikipedia are stumped by a number of math-y articles that link to Matrix model disambiguation page. Please see this "dablink-list" (which shows 7 articles now), hit "FIX" on any one of them, and see if you can identify which version of "matrix model" should be linked. If you don't know, just exit / delete the tab that has opened up. It is easy and fun to use this cool disambiguation-related tool, but you have to know something about the content area to fix these seven ones. TIA, --doncram 07:03, 29 July 2015 (UTC)

Branches of geometry

Any opinions of this new article? Michael Hardy (talk) 00:09, 29 July 2015 (UTC)

It does seem a bit less unwieldy than list of geometry topics, but... Is there some sourcing for this structure, or is this just some editor's opinion of what the important topic groupings are? Why projective and affine geometry but not inversive geometry? Why is Minkowski geometry listed as a subset of affine geometry, and why is it included at all when we have no article specifically on that topic? Is the first group of topics really classified by axiomatization, rather than by symmetry groups (per the Erlangen program)? Why is Riemannian geometry listed as a top-level topic instead of being a subtopic of differential geometry? Where are convex geometry, discrete geometry, computational geometry, and synthetic geometry supposed to fit? Is this a listing of branches of geometry, or a listing of geometrical branches of modern mathematics research, sweeping the parts of geometry that get taught to schoolchildren under the single Euclidean geometry link? —David Eppstein (talk) 00:24, 29 July 2015 (UTC)

[edit conflict] I don't know where to begin. For one thing, such classifications are usually original research, in my experience. Mgnbar (talk) 00:28, 29 July 2015 (UTC)

I may add to the points set by David that the relation between the different branches of geometry are much more complex that that suggested by the structure of this article. For example, projective geometry and affine geometry are both considered in synthetic geometry as well as in analytic geometry, and none; of these branches are uniquely defined by sets of axioms. IMO, this is in geometry that the main branches of geometry, and their relations should be described. Therefore, I suggest to merge this article in geometry. D.Lazard (talk) 08:34, 29 July 2015 (UTC)

I started that page, on this page my idea was to construct some kind of scheme that sorts out the parent (less axioms) -child (more axioms) relations between the different (mostly synthetic geometrys, but haven't found a lot of time for this yet (and also became confused, to name two:

• There are different opinions what non-Euclidean geometry means: Is it absolute geometry or is spherical geometry also a part of it.
• Is Minkowski geometry really an affine geometry? (Not all axioms of incidence geometry in particular every two points are on a line)

The only reference I have till now is Soeder, Fritz Reinhardt ; Heinrich (2001). Dtv-Atlas zur Mathematik : Tafeln und Texte (Orig.-Ausg., 12. durchges. Aufl. ed.). München: Dt. Taschenbuch-Verl. p. 128-129, 136-137. ISBN 3-423-03007-0.{{cite book}}: CS1 maint: multiple names: authors list (link)

Maybe it is not the right page for a page about this, but I think such a page would be an good addition to WP WillemienH (talk) 09:44, 29 July 2015 (UTC)

The list is also missing global analysis/geometric analysis, pseudo-Riemannian geometry, non-commutative geometry, elliptical geometry, tropical geometry. Also, one might look at the AMS classification to see other areas that we've missed. Sławomir
Biały 13:32, 29 July 2015 (UTC)

This first thing that stood out for me was the division between geometry with different axioms vs other types. You can divide geometry by synthetic vs. analytic, and also by Euclidean vs. hyperbolic vs projective vs. whatever, but these are orthogonal classifications. Projective geometry can be treated synthetically or analytically just as easily as Euclidean and the same goes for many other types. So while I'm not sure that the division in the article is wrong, the way the topics have been split between them seems arbitrary. Also, it's not clear how this article, when the missing branches are filled in, would differ meaningfully from List of geometry topics if some of the clutter was removed from that article. In other words it seems like we now have two articles with the same purpose. --RDBury (talk) 21:21, 29 July 2015 (UTC)

Aug 2015

"Thus"

The usage and primary topic of Thus is under discussion, see talk:Thus (company) -- 67.70.32.190 (talk) 06:56, 1 August 2015 (UTC)

good article nominations

There is at the moment (july-october 2015) a GA cup running for reviewing good article nominations Wikipedia:WikiProject Good articles/GA Cup but there is a distinct lack of mathematics article nominations Wikipedia:Good article nominations#Mathematics and mathematicians there are only 3 (one nominated by me, another I think a straight fail for another ). Are there no other mathematics articles to nominate ? WillemienH (talk) 07:57, 1 August 2015 (UTC)

Section "Selected publications" in biographical articles

Hello everybody. What do the Wikipedia's policies have to say about the articles about mathematicians having a section with selected publications? It's common practice to add one (I personally like it, because in a quick look at just the titles of the articles and journals one can already get some ideas about the research of the academic), but it seems that there is no specific policy about it. 189.6.202.87 (talk) 23:24, 29 July 2015 (UTC)

See Wikipedia:Manual of Style/Layout#Further reading. JRSpriggs (talk) 23:45, 29 July 2015 (UTC)

• JRSpriggs, that's a different thing--"Further reading" and "External links" is for material about the subject, not material by the subject. Drmies (talk) 00:17, 30 July 2015 (UTC)

• As I discussed with the IP elsewhere, in a prettier place, I believe we should not be a resume service. Published books, maybe--published articles, definitely not. Or, where's the limit? Do we include conference presentations--and at what kinds of conferences? No, this is not a good idea. Drmies (talk) 00:21, 30 July 2015 (UTC)

I think this is a good idea, and have added such sections to many articles. The part that's a bad idea is having a "Publications" section that is not selective and lists everything (as a cv would). My tendency is to aim for a selecton of 4-6 publications (fewer if there are not enough important ones, more in rare cases when someone has many very significant works) and only include ones that have very large numbers of citations, are published in top journals, have specific mention in secondary sources as being significant results (especially if these results are also mentioned in the rest of the article), or have been given noteworthy awards. For some mathematical subjects such as theoretical computer science where conference publication may be more important than journal publication, yes, I'll definitely include conference papers too, but replacing some of the 4-6 journal papers rather than adding to them. —David Eppstein (talk) 01:37, 30 July 2015 (UTC)

• Thanks David. Of course, all the editors in chief will be arguing that theirs is the top article... But awards, for instance, or "widely cited" (shouldn't be too hard to prove), I think that's a good reason for inclusion. Somewhere on our beautiful project it says something about "has exerted great influence", and we should honor that of course, and we can, in this case, too. For example, even if Tolkien's Beowulf speech ("The Monster and the Critics") had never been separately published, it would have been one of the most notable conference key note addresses ever and worthy of being listed. Drmies (talk) 01:44, 30 July 2015 (UTC)
  • And by "top" in pure mathematics I mean pretty much only JAMS/Annals/Inventiones. Otherwise you're going to have to convince me by something other than the journal name that it's worth including. —David Eppstein (talk) 02:35, 30 July 2015 (UTC)
    • Sure, but such guidelines aren't easily applicable across Wikipedia. If I were to ask my poet friends for the notable poetry journals, I'd get a list of hundreds. Same, really, in literature, unless in a very specific field (such as mine, haha). But I do believe we should allow for editorial discretion, which is why I've never been against a kind of gatekeeping model for the different areas in Wikipedia--but don't tell the folks on Jimbo's talk page or on Wikipediocracy that I hold such elitist views, blatantly favoring people who know their ass from their elbow over those who don't. Drmies (talk) 15:25, 30 July 2015 (UTC)
    • And where did you get that shirt?? Drmies (talk) 15:25, 30 July 2015 (UTC)
      • Which shirt? —David Eppstein (talk) 16:32, 30 July 2015 (UTC)
        • On the website linked from your user page. I clicked because I've never seen a real-life mathematician. Very exciting! Drmies (talk) 17:25, 30 July 2015 (UTC)
          • So I'm guessing you mean either the Somos sequence shirt from here or the "Math is delicious" shirt from here. The first one was from a research group I had some minor contact with and probably can't be obtained now. The second one is from the questionable content webcomic, but doesn't currently seem to be available from their merchandise store. —David Eppstein (talk) 18:05, 30 July 2015 (UTC)
            • This one. :) Drmies (talk) 19:32, 30 July 2015 (UTC)

I have one small gripe, that could be fixed by some industrious WikiGnomes no doubt. We often do not provide useful links to old works whose copyrights have expired. (Google books, Archive.org and Project Gutenberg all maintain free collections, and there are other projects with more specific holdings, like the Euler archive.) For example, very few of Leibniz' works are linked. The significant Nova Methodus pro Maximis et Minimis has its own article, which also lacks a link. The Latin works of Euler are mostly missing as well. It seems like these would be useful links for scholars in the field. Sławomir
Biały 12:41, 30 July 2015 (UTC)

• See, for the dead ones there isn't much of a problem as far as I'm concerned--there's not much resume padding for dead people. A link can be added, in your example, to the article on the book--there is nothing wrong with that; we're really talking about a different problem. I suppose WP:EL can allow for such links, though the risk is always that articles get turned into linkfarms. But here we're talking (I assume) about living people and their lists of publications, where we should be very wary, esp. in the medical field, for instance, or in physics, where we need editorial discretion to prevent people from listing a million things. Or think of those books about God and prayer you can pick up at the pharmacy (in the US, anyway)--those authors churn those out by the dozens, and we shouldn't be listing all of them. Drmies (talk) 15:25, 30 July 2015 (UTC)

• Certainly works which themselves meet the notability criteria should be listed. I would think that works for which the subject is known should be included as well. As an example, I just happened to have the article on Giusto Bellavitis open; there is a Works section with four entries and that seems a bit light. But even for copyright expired works there should be a line; we don't need to list someone's comment on somebody's solution to a problem posed by whosit. For actors there's no problem with listing every bit part and every guest appearance in a TV episode; but I guess, for some reason, most people are more interested in actors than mathematicians. --RDBury (talk) 19:47, 30 July 2015 (UTC)

Thanks to everyone who participated! I've already memorized David Eppstein's criteria. This edit should be fine I guess. :D 189.6.202.186 (talk) 04:06, 1 August 2015 (UTC)

Maybe this one is listing too many. Anyway, I won't change it, I've just pointed it for the case someone feels inclined to edit there :D (that article is really needing a lot of work). 189.6.202.186 (talk) 04:37, 1 August 2015 (UTC)

I generally agree with "David Eppstein's criteria", but the two examples in the last posts show that more deserves to be said: Most article about mathematicians have a section describing their main contributions. Sometimes, these contributions are the object of a specific article, which is normally linked. But, when it is not the case, (and also in this case), it is useful to read the original article. Even when a short selected list of publication exists, such as in James Harris Simons, it may be difficult to know which article corresponds to which main contribution.

Therefore, I would suggest to organize the selected list of publications as a list of references, linked from the section on main contributions. The criterion for inclusion, will then to have one, or at most two, linked publications by subject described in main contribution section. As usual, this section requires also references to secondary sources, but, IMO, this is a case where some primary sources are useful. An example of the bad result of systematically avoiding primary sources in this case is Andrew Wiles article: he is known for one paper; this is amazing that one cannot find the reference of this paper in the article about him! On the other hand, there are mathematicians that are known for many publications, each of them being relatively minor. In this case, a short list of selected publications is difficult to establish (and would be original research), and it is better to omit such a list. Paul Erdős is a clear example of such a case. D.Lazard (talk) 09:09, 1 August 2015 (UTC)

Even for Erdős some of his papers are more famous than others. The one with the elementary proof of the prime number theorem; the one introducing the Erdős–Rényi model of random graphs; the one that first uses the probabilistic method, all are particularly noteworthy. —David Eppstein (talk) 16:18, 1 August 2015 (UTC)

AfC submission

Does anyone have any objections to my decline reason on Draft:Integrative Propositional Analysis? Best, FoCuSandLeArN (talk) 16:28, 3 August 2015 (UTC)

Pretty sure this should be under Linguistics or Philosophy or some other project. In any case, the decline reason wasn't clear to me; are you claiming it's from a single source? Self-promotion? --RDBury (talk) 20:14, 3 August 2015 (UTC)

Project template

Please reconsider the use of {{WikiProject Mathematics}}; it's a disservice to our fellow editors to expect them to use a different protocol for one project, than the one they use for most others. Also, the claim that "The list of mathematics articles already has a list of all math articles" is false; it does not include new articles of relevence to this project. Andy Mabbett (Pigsonthewing); Talk to Andy; Andy's edits 11:20, 27 July 2015 (UTC)

What's going on with Jitse's bot? Any update? Should we try to get something else going? Sławomir Biały (talk) 12:41, 27 July 2015 (UTC)

That template has been obsolete for six years (see the history); what's the issue? Ozob (talk) 13:51, 27 July 2015 (UTC)

The issue is that when an editor uses the template, expecting it to work like most every other project's equivalent, it does not. Andy Mabbett (Pigsonthewing); Talk to Andy; Andy's edits 14:57, 27 July 2015 (UTC)

Oh, I see, you want us to use {{WikiProject Mathematics}} instead of {{maths rating}}. Sorry, I thought you meant something different. It shouldn't be hard to overwrite the current {{WikiProject Mathematics}} and replace all current uses of {{maths rating}}. I wouldn't object to that, though perhaps my opinion shouldn't count as I've never been involved in that kind of work. Ozob (talk) 01:02, 28 July 2015 (UTC)

List of mathematics articles no longer links to the list of mathematics articles but instead redirects to something else. Michael Hardy (talk) 22:30, 27 July 2015 (UTC)

And now I've recreated something similar to the former page that gave the alphabetical list of pages. List of mathematics articles now redirects to that. Michael Hardy (talk) 22:56, 27 July 2015 (UTC)

AIUI, article-space redirects should not go to Wikipedia: space pages. Andy Mabbett (Pigsonthewing); Talk to Andy; Andy's edits 09:55, 28 July 2015 (UTC)

I have just done this edit. The statement I deleted has been grossly false for several years. I edited the page that redirected list of mathematics articles to make it a disambiguation page including a link to the actual list. But a user called The Banner insists on reverting without addressing the inappropriateness of the target of the redirect or of the fact that we had that statement on a template directing many thousands of articles to that inappropriate redirect page. If Jitse's bot does not get reactivated, we need to decide what to do about that. Michael Hardy (talk) 20:22, 3 August 2015 (UTC)

It links to Wikipedia:WikiProject Mathematics/List of mathematics articles. In my opinion, that is linking to a wikiproject. So I was bold enough to revert your edit. My only concern was to free Template:Index of logic articles from a link to a disambiguation page. And that was exactly what I have done. Who screwed up and how to solve that is not my concern. The Banner talk 20:25, 3 August 2015 (UTC)

And now I've done this edit, linking to the actual list of mathematics articles. Michael Hardy (talk) 20:57, 3 August 2015 (UTC)

Future of MathJax on wiki

A volunteer has proposed removing client-side MathJax from Special:Preferences#mw-prefsection-rendering in phab:T99369, in favor of modern (up-to-date and probably faster) browser plugins. This will probably affect very few readers and editors, but it's likely to affect more people in this group than anywhere else, so I wanted to make sure that you heard about it. It will also be announced in the next m:Tech/News. Whatamidoing (WMF) (talk) 01:10, 17 July 2015 (UTC)

How can a "browser plugin" possibly work if there is no preference setting to produce output in a form that the browser plugin can parse? How does this relate to the "no special browser setup required" core goal of the MathJax project? How can this possibly avoid causing problems rendering Wikipedia pages that also include dollar signs as text characters? Where are the user tests showing the availability and working condition of these supposed browser plugins? And how does this interact with recent network-wide security alerts advising us to disable all auto-running plugins? To me this sounds less like an improvement and more like gratuitously breaking something that works because the person proposing the breaking doesn't care whether it works. Additionally, is there any hope of fixing the current problem that it is not possible to set the user preference to render math as MathJax without at the same time breaking the display of math formulas in the mobile app (which does not support MathJax)? If the developers' attitude to the decade-long disaster of bad math formatting on Wikipedia (and the only-very-recent and grudging support of decent MathJax formatting) is to step backwards and punt to someone else's browser plugin then I have very little hope for the future here.

And the framing of the proposal completely misses the point. It doesn't matter what we individually as mathematics editors are using to view Wikipedia; what matters is the default view, and how easy it is to format articles for that view. As editors of mathematics, what we have now are three incompatible and partially broken systems for getting the equations viewable by users: inline wiki-formatting (very limited and tricky to format but always works and produces a rendering compatible with the inline text), a system of templates (somewhat limited and even trickier but with better appearance), and <math> (can format essentially all equations using much better markup but underused because the default appearance is so ugly). Incorporating MathJax into the wiki at least gave us the option of full math with good appearance, and the hope that MathJax might eventually become the default view giving us a single good editing option. Now you're pulling the rug from under us, saying we'll be stuck with these editing incompatibilities forever, and that only power users who install special plugins will ever see well-formatted <math>. This seems like a huge step backwards. —David Eppstein (talk) 01:37, 17 July 2015 (UTC)

It says in that messy link,

Client side MathJax rendering is outdated. There are browser plugins that support MathJax rendering for chrome. The advantage with those plugins is that they use the most recent actively maintained version of MathJax and do not require that users log in.

(my emphasis) As far as I can see, this means that the default rendering mode will be MathJax (now PNG). This is not a small step as it will affect the vast majority of readers, at least those who use Chrome. (I just suppose the server can figure out that it is Chrome that requests a page, and that the appropriate plug-in is present.)

It will probably affect, as David notes, editors in this group the least, since many use MathML by choice, and others PNG by choice because it has, by far, the fewest bugs of the current options. YohanN7 (talk) 03:08, 17 July 2015 (UTC)

I think you are mistaken in claiming that this change will mean "the default rendering mode will be MathJax". Browser-plugin MathJax requires that the server sends the browser the LaTeX source code. So if this were to become the default rendering mode, users without the plugin would just see LaTeX source instead of rendered equations. This is such a bad choice that I think even the Wikimedia developers would eschew it. My interpretation of your quote about not requiring logins is that the developer did not think about this and did not realize how bad that would be as a default before proposing to kill any alternatives. —David Eppstein (talk) 03:22, 17 July 2015 (UTC)

It is not a claim of mine. It is an assumption based on what I quote. Client and server do actually have a little chat before the bulk data is sent, so, it is , at least in principle, possible to send plain LaTeX to clients having Chrome and appropriate plug-in. YohanN7 (talk) 11:02, 17 July 2015 (UTC)

While in principle it's great that the WMF is dropping by to see what the users want, it is less encouraging that the users have been saying the same thing for years now: give us working mathjax. There was a detailed proposal made last year that summarized the user's needs, back when WMF was apparently threatening to remove mathematics support altogether. Does this mean that WMF actually now cares enough about the users to take what they ask for seriously and budget for the addition of fully-fledged mathjax support for mathematics rendering? Or is this post just a token gesture, so the WMF can pat themselves on the back and say that the users were consulted, only to ignore them again? Sławomir Biały (talk) 12:12, 17 July 2015 (UTC)

Sławomir, "the WMF" is not doing this. As I clearly stated in the very first words of my message, "a volunteer" has proposed this.

Also, the WMF has never considered removing support for mathematics. I remember the hyperbolic claims that editor and his sock made – leaping straight from a designer saying that he wasn't certain how many different maths systems Flow would ultimately support straight to the destruction of all maths content in all namespaces – but those claims never had any basis in truth. In fact, at the time that he was spreading that drama, Flow already supported maths in the formats that he preferred. Whatamidoing (WMF) (talk) 17:45, 17 July 2015 (UTC)

But the WMF should be doing this: maintainance + development of math rendering architecture. Shouldn't it? Why do we need to rely on volunteers? If the WMF can devote engineering resources to stuff like Visual Editor, then surely it can devote some small fraction of the resources to the math support. The message we're getting is that math is not a priority; I understand it is less of priority than flow or VE. But I'm not quite happy that it is not a priority of any kind (and thus delegated to outsiders). -- Taku (talk) 18:35, 17 July 2015 (UTC)

It was Physikerwelt who suggested this change. I'd like to invite him to provide an explanation. @Physikerwelt: As I said on the task page, as best as I can tell, the plugin you're talking about is a third-party creation not supported by the MathJax team, and there are no corresponding plugins for other browsers. Why do you think that switching to this plugin would be an improvement? Ozob (talk) 14:56, 17 July 2015 (UTC)

Quouting myself from the Phabricator ticket:

"The currently enabled MathJax availible to the users is a old version that branched of from an old version. It's also unmaintained i.e. not supported by the MathJax team. The customization of the MathJax codebase is quite heavy. Updates made to MathJax (for example security updates) are not reflected in the customized wmf clone.

From a conceptual perspective this heavy customization of MathJax seems to suboptimal and the past has proven that is is unmaintained.

I would be interesting, if there are Firefox users that prefer MathJax over MathML.

For the future, we are going to do exactly that was proposed on the discussion page and also envisioned here T78046."

A more detailed overview about the new MathML rendering mode is availible from here http://arxiv.org/abs/1404.6179 I promise to review every code that is contributed to the math extension. So if someone is willing to update the current MathJax plugin this is defenity an alternative. However, my current focus is on the MathML rendering mode that still has some issues that need to be resolved. --Physikerwelt (talk) 15:30, 17 July 2015 (UTC)

@Physikerwelt: you are wasting your own time by chasing a chimera and in the process taking Wikipedia farther away from the path to working math markup. That arXiv preprint on mathoid, in its user requirements, omits the main one that has caused all of the problems for all of these years: the math generated by it must not look ugly. After all, <math> has existed for the last decade and has produced valid mathematical formulas for most of that time (modulo a few bugs here and there). What has not existed is math markup that is so well integrated into the text (in terms of font matching, baseline matching, size matching, scalability, etc) and so well spaced (up to the standards produced by Knuth in TeX), even in the default not-logged-in-vanilla-browser view, that nobody would consider formatting mathematics any other way. Instead, we have this horrible profusion of different editing styles, precisely because the default not-logged-in formatting of <math> is ugly. MathML is not good enough. It is not formatted as well as MathJax and in any case is a non-solution for the default view because Chrome does not natively support it. On the other hand, MathJax is well formatted and (in theory) usable by almost all. MathJax for all would solve our problems, and I don't think anything less would be good enough to get math formatting back on track here. If the problem is that Wikimedia's MathJax code is old and crufty and overcustomized, why not put some effort into updating it? The bottom line is, if you're not working towards the goal of making the default not-logged-in view at least as high-quality as MathJax, then you're not helping, because that not-logged-in view is the beginning and end of all our math markup editing difficulties. —David Eppstein (talk) 16:23, 17 July 2015 (UTC)

Here a side by side comparison of the different maths rendering modes.

Comparison of different maths rendering modes of a section of https://en.wikipedia.org/wiki/Help:Displaying_a_formula

If it were not for the baseline, aliasing and font size problems the PNG rendering looks good, MathJax is good with a couple of glitches, but to me the firefox MathML looks like a project still in need of a lot of work to get it looking really good.--Salix alba (talk): 01:14, 20 July 2015 (UTC)

Thanks for this comparison. I would expect that, in principle, SVG could be better at the aliasing issues than PNG, because it can be rendered into pixels after already knowing what kind of display it will be shown on, allowing subpixel-resolution color-fringing tricks. In practice, the view I get from Wikipedia's SVG (pretty much what you show in the Chrome view of your screenshot) looks overly-thickened and overly fuzzy. Not to mention that it still has bad font sizing and baseline issues. —David Eppstein (talk) 03:23, 20 July 2015 (UTC)

The MathJax option has now gone. If you want client side MathJax in Chrome you can use the Wikipedia with mathjax extension. (github page.)

MathML rendering in firefox is improved quite a bit with the mathml-font extension.--Salix alba (talk): 12:29, 24 July 2015 (UTC)

This news is very disappointing. Unfortunately, WMF has already made clear its antipathy to the needs of the users. Over a year ago, I told WMF representatives that working MathJax should be made an immediate priority. Later, this project put together a detailed plan for the future of MathJax. Apparently, these recommendations were not passed along to the engineering team. I think it's time to bring Jimmy Wales into this again. I think Salix's picture illustrates nicely why the current status quo is not acceptable. Sławomir Biały (talk) 12:53, 24 July 2015 (UTC)

(I'm probably stating the obvious, but anyway). The volunteer developer (developers?) seems to have the attitude that he knows what is the best and not particularly interested in what math editors or readers of Wikipedia would like to have. The WMF has, essentially, no plan ("no plan" is still a plan?). It would be "nice" if we can have some kind of long-terms plan. Of course anyone or any community can come up with a plan. For it to be implemented, a commitment is needed from someone and some organization. If that's not WMF, I don't know what else. @Whatamidoing (WMF):. I get improving (actually just fixing) math rendering would not increase, say, female editors. But a small amount of commitment should be reasonable in my humble opinion. -- Taku (talk) 19:48, 24 July 2015 (UTC)

Pilot studies have shown that improvement of MathJax rendering will increase the participation of female, disabled, minority and socioeconomically disadvantaged mathematics editors and readers by over 5000%. Studies have also shown that the old style PNG rendering is preferred primarily by white Anglo-Saxon males, which already constitute the bulk of our editing community. In diversity studies, MathML features only marginally better, largely with the small but growing "hipster" crowd, consisting mostly of white Americans (both male and female) in their late 20s, who enjoy the "retro" look of the MathML font. But our Wikipedia mission is to improve access to all the peoples of the world, regardless of their race, creed, color, gender, socioeconomic status, or language. And reinstating and improving the MathJax extension is vital for the WMF in its continued long term mission of improving access. This is especially important in the mobile market, already the primary way readers interact with the project, and one that is projected to have long term growth potential. In fact, because of this long term growth potential, most of the web has already opted against server-side rendering in favor of light-weight client side apps, relying heavily on AngularJS, AmberJS, and Backbone extensions. MathJax rendering support is vital for the long-term viability of the Wiki foundation projects, one that will bring back in multicultural, ethnic, and multi-gendered support to our mathematics editing and reading community. Cloud computing and Microsoft Azure technologies can help engender this, as we quantum leap forward into the new millennium. Sławomir Biały (talk) 23:29, 24 July 2015 (UTC)

Do you actually have links for any of this? If so I'd be very interested in seeing them. —David Eppstein (talk) 00:09, 25 July 2015 (UTC)

http://www.seven.co.nz/assets/image/full/iiuqGEd.jpg I mean, really... "quantum leap forward"? Sławomir Biały (talk) 00:21, 25 July 2015 (UTC)

Well yes, hence my use of "actually". But there should be usability studies of MathML vs MathJax in different populations, and I'd be interested in seeing what such studies might have to say. —David Eppstein (talk) 00:28, 25 July 2015 (UTC)

It turns out to be quite simple to use MathJax with a user script. All you need is to set the raw tex preference and add

window.MathJax = {
    tex2jax: {
      inlineMath: [ ['$','$'] ]
    }
  };

mw.loader.load( 
	'https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS_HTML');

to your Special:MyPage/skin.js. This might not be the fastest way of doing things but its developer independent.--Salix alba (talk): 07:59, 25 July 2015 (UTC)

@TakuyaMurata: You mentioned "no plan" I have been trying to get input on a plan for several years now ... jude by yourself https://www.mediawiki.org/wiki/Extension:Math/Roadmap ... for me capturing math semantics is much more important than the technical details of the rendering. I think mathoid will improve the rendering for most users and especially for those using browsers that fully support HTML5. However, much more important than the rendering itself is a cleanup of the markup to capture more semantics and allow for additional services such as math search or import export function to computer algebra systems. But therefore we need to get rid of all the problems (and there are a lot more than you might imagine) that the Math extension at this very moment. With the current code basis it is very hard to make progress at all. Therefore I'm trying to recruite a second volunteer how can help with code review or with parts of the implementation. I even wrote a guid to demonstrate how simple it is to review the math extension code at [31] but until now... I'm still searching.

Everyone is free to decide what's the right way. Either blame me and WMF that we are not making sufficent progress or open an IDE and help coding.--Physikerwelt (talk) 19:52, 28 July 2015 (UTC)

I think your priorities are wrong and that those wrong priorities in you and others have played a large role in why mathematics markup and rendering here has been so badly screwed up for so long. The top priority should be: is mathematics presented well to all readers. Second should be: is it easy for editors to generate good presentation of mathematics. Maybe third should be performance issues. A far distant fourth, useful mainly only to the extent it can help in the other three priorities, is: does the server-browser communication channel have a clean semantics. Because frankly who but a developer would or should care about that? —David Eppstein (talk) 20:40, 28 July 2015 (UTC)

To be clear, I said the WMF has no plan, and I am assuming that a volunteer such as yourself @Physikerwelt: is not a part of the organization (yourz're not in the payroll). This seems to be a main issue: since it creates a response that if there is a problem, fix it yourself. Personally I don't have any technical problem (I use MathML with SVG on iOS devices and are perfectly happy). As David Eppstein said (and in fact, I'm mostly simply repeating him here), this is about the presentation of math to the readers. The WMF's perception that some math "editors" may get inconvinicened by the removal of MathJax is thus missing the point.

I think the work on the semantic aspect is important and interesting; it may even make sense to have some computer algebra system support to generate some figures (I have heard nowadays one uses the computer to do concrete calculations with, say, polytopes in the representation theory.) It seem that you are more interested in that type of work and there is nothing wrong with that. I'm merely saying (as David Eppstein does) that this aspect is somehow irrelevant to the issue in hand. -- Taku (talk) 22:33, 28 July 2015 (UTC)

@David Eppstein: I think we agree on the priorities for math rendering some more details:

1) "is mathematics presented well to all readers"

all readers includes readers with limited vision, limited bandwidth, old hardware, working in secure environments

2)"is it easy for editors to generate good presentation of mathematics"

if LaTeX is referred as easy I agree. I personally think that clean semantics should imply good presentation i.e. i prefere $\sin{x}$ over $\mathrm{sin} x$. I'm a little bit sceptical about visual editing tools since some make it much harder to edit more complex formulae i.e. if there is no way back to LaTeX

3) performance

as long as the performance is reasonably good that does not matter at all... otherwise it's a problem of type 1

4) server browser communication

this is not a priority at all. However, since different users use a huge variety of browsers some form of standard is required for browser client communication. Otherwise the maintenance effort explodes.

@TakuyaMurata: cas integration is one thing I'm planning to work on in my regular job. I'm looking for a master student and we are going to start with the DRMF and Wolfram eCF project. --Physikerwelt (talk) 08:46, 29 July 2015 (UTC)

I just posted a long and somewhat ranty blog post about these issues. If you care, you can find it at http://11011110.livejournal.com/314841.html — anonymous responses should be possible there (but will initially be invisible until I review them as a spam-prevention measure). —David Eppstein (talk) 06:24, 5 August 2015 (UTC)

Quite interesting. A small remark: Wikimedia is indeed the nonprofit organization... but the software on which Wikipedia runs is rather Mediawiki. Boris Tsirelson (talk) 07:03, 5 August 2015 (UTC)

Thanks, corrected. —David Eppstein (talk) 07:15, 5 August 2015 (UTC)

Nice post, David. A few remarks:

• I use Firefox with MathML for my daily editing on my desktop and Chrome with SVG fallback on my smartphone (desktop, not mobile version). Barring a few minor issues, which nevertheless should be fixed, I am quite happy with either combination. The foremost reason that MathML is not a universal solution is that most browsers don't natively support it. It seems one reason why the MediaWiki developers try to push MathML is to convince browser developers to natively support it, but I don't think that this will work out. The SVG/PNG fallback looks good, even better than MathML.
• Having clean semantics would be nice, but that's not a problem of MathML but of LaTeX. Actually it's not a problem of LaTeX either but of the fact that formulas are entered without semantics in the first place. If we would agree on a set of macros and replace for example \cdot by \multiplication, \innerproduct, \groupoperation or whatever the meaning is (and the editor of an article is the best source for this information), we could also provide semantics from inside LaTeX. But changing all formulas accordingly would be a terrible amount of work. Also, agreeing on a standard set of macros and convincing the MediaWiki software engineers to include them could be problematic.
• The current SVG/PNG fallback does not have the font size and alignment issues of the current PNG support. Actually, I don't understand why the current PNG support is not fixed in this respect since there obviously is a MediaWiki solution for these problems. Other limitations of inline images still apply of course.
• Using HTML markup for mathematical formulas is an incredibly terrible idea due to inconsistent display and also for semantic reasons. In the German Wikipedia we try to avoid these, despite the current ugly PNG support. There are still some older articles with such markup, though. We also don't use the math templates.
• The main problems with MathJax are rendering speed and text reflow. In my opinion these are not minor problems but they significantly reduce the fun of browsing articles and editing them. This especially applies to mobile devices. But this is no reason to discontinue the MathJax support in MediaWiki since MathJax might improve in this respect in the future. By the way, MathJax can also parse MathML, but this seems to be slower than directly parsing LaTeX.

Best wishes, --Quartl (talk) 11:10, 5 August 2015 (UTC)

Maybe for you on Firefox the SVG fallback (and whatever rendering preferences you've set) doesn't have sizing/baseline issues but for me on Chrome with my settings it clearly does. —David Eppstein (talk) 14:00, 5 August 2015 (UTC)

I have selected "MathML with SVG or PNG fallback" in Preferences/Appearance. On Firefox, I get the MathML display. On Chrome, which doesn't have MathML support, I get SVGs. Compared to selecting "PNG images" in the preferences, the font is cleaner, significantly smaller and better adapted to the rest of the text. The baseline is not perfect, though, and in places off by few pixels. Best wishes, --Quartl (talk) 14:33, 5 August 2015 (UTC)

Here's a simple test: does ${\text{this sentence}}$ look normally formatted to you, with no font changes, misalignment, or other special emphasis on any of its words? Is that still true if you use your mouse or other pointer device to select the text of the sentence? If so, congratulations, your math formatting setup works better than mine. —David Eppstein (talk) 14:58, 5 August 2015 (UTC)

I get the following:

• Firefox: 'this sentence' has a different font with slight serifs, slightly smaller than the rest of the text, but perfectly aligned. Selction, cut and paste works.
• Chrome: 'this sentence' has a different font with pronounced serifs, slightly larger than the rest of the text, about two pixels lower. Can not be selected (SVG).
• Explorer: 'this sentence' has a different font with pronounced serifs, significantly larger than the rest of the text, several pixels lower. Can not be selected (SVG).

The results in Firefox and Chrome would be tolerable to me if 'this sentence' was a formula, especially in comparison to the current PNG rendering. The result in Explorer is only marginally better than the current PNGs. It probably all depends on the font setup. In Firefox I do have an add-on called 'MathML-fonts 2.1.1-signed', but turning it on or off seems to have no effect in this case. Best wishes, --Quartl (talk) 15:37, 5 August 2015 (UTC)

A further test: How looks ${\text{this sentence}}$, compared with this sentence? For me, with Firefox and "MathML with SVG or PNG fallback", the first one with <math>, and the second one with {{math}} have rather similar fonts (slight serif), well aligned, but the first one is significantly smaller than the current text, and the second one slightly larger than the current text. Copy and paste gives: "How look this sentence {\displaystyle {\text{this sentence}}} , compared with this sentence?" Note the space before the comma introduced by <math>, and the \displaystyle introduced by the copy and paste (this probably explains why so many articles have this \displaystyle in every <math> formula, producing tiny and almost unreadable fonts).

Because of this this behavior, my preferred edit option, is, for the moment, to use {{math}} when possible, and <math> when impossible or for complicated formulas. The small font of <math> is somehow an advantage for complicated formulas, because of more compact formulas. D.Lazard (talk) 16:25, 5 August 2015 (UTC)

In Firefox, when I just select and copy 'this sentence' I just get 'this sentence', but if I select the the whole sentence I also get the displaystyle stuff. Probably, the MathML text annotation generated by MediaWiki is not good here or this is a feature of the MathML browser support. The extra space before the comma is a MediaWiki bug that was reported long ago. \displaystyle should have no effect on normal text, if anything it should produce larger symbols like $\displaystyle \sum$ compared to $\textstyle \sum$. Best wishes, --Quartl (talk) 16:52, 5 August 2015 (UTC)

I have no idea how to tackle the additional whitespace problem. I can not reproduce the problem on any test system. See for example http://math.beta.wmflabs.org/wiki/User:Admin. It might be connected with HTML tidy or custom sylesheets. If anyone has additional (in which processing step the additional whitespace is introduced) please comment on https://phabricator.wikimedia.org/T106855. A similar problem is https://phabricator.wikimedia.org/T103269... I have no idea where the information displayed in the section heading come from.--Physikerwelt (talk) 17:27, 5 August 2015 (UTC)

Using HTML markup for mathematical formulas is an incredibly terrible idea due to inconsistent display...

It is also the only workaround in existence. Most users get PNG rendering and what they see is not "inconsistent display". They see _{INCONSISTENTDIS PLAY} with inline Latex, and this will not change the forthcoming years as it looks. I find articles with much inline Latex unreadable. (I mostly use PNG because the articles I edit (not to mention my sandbox) tend to be big (making MathJax impossible due to poor performance) and contain plenty of formulae (making MathML impossible due to bugs)). HTML has, after all, acceptable appearance - even tough it doesn't match 100% with what's in the displayed equations (in whatever mode). YohanN7 (talk) 17:50, 5 August 2015 (UTC)

Yes it's a (bad) workaround and its existence has exonerated the software developers from providing a viable solution for the math rendering problem. I completely agree with David on that point. Should MathML, MathJax or anything else become the standard rendering system at some point in the future (hopefully soon), all formulas typeset in HTML will still look as inconsistent as they do now. Best wishes, --Quartl (talk) 18:11, 5 August 2015 (UTC)

Yes, formulas typeset in HTML will look as inconsistent as now, but no worse. That is my point. The inconsistency is aesthetically bearable, while inline PNG Latex is not. I don't see anything becoming standard anytime soon. When something comes around, it should take a skilled volunteer (which is what we rely on) no more than a week to develop a working HTML->Latex robot. To be specific, I am referring almost exclusively to the template "math", which isn't used for complicated formulae, but rater writing x = y inline. Cheers! YohanN7 (talk) 18:59, 5 August 2015 (UTC)

You are a true optimist :-). A few months ago, I manually converted the German version of Combinatory logic from HTML markup to LaTeX. Even using advanced search and replace commands this was a horrible job. Best wishes, --Quartl (talk) 19:48, 5 August 2015 (UTC)

(ec) And that's exactly what I wrote it for. My hopes are that someone will implement MathJax server-side, so that it can spew out HTML/CSS to the browser, simple as that (webfont still needed though). -- [[User:Edokter]] {{talk}} 19:51, 5 August 2015 (UTC)

If I understood correctly, MathJax is already running server-side to perform the LaTeX → SVG and LaTeX → MathML conversions. Best wishes, --Quartl (talk) 20:03, 5 August 2015 (UTC)

I keep forgetting that. Then all that is needed is to send the HTML/CSS to the browser instead of an image renderer. -- [[User:Edokter]] {{talk}} 08:30, 8 August 2015 (UTC)

Removed fullstops at end of equations

An anonymous user removes fullstops at end of equations in "Expected value". Is this a good idea to do? Boris Tsirelson (talk) 12:14, 10 August 2015 (UTC)

Looking closely I see that the first of these fullstops was indeed spurious. But the others were not. Boris Tsirelson (talk) 12:17, 10 August 2015 (UTC)

In my own writing I feel that every sentence should end with appropriate punctuation, even if it ends in an equation. --JBL (talk) 12:22, 10 August 2015 (UTC)

Per MOS:MATH#PUNC, "Just as in mathematics publications, a sentence which ends with a formula must have a period at the end of the formula." A footnote explains "This style, adopted by Wikipedia, is shared by Higham (1998), Halmos (1970), the Chicago Manual of Style, and many mathematics journals." Sławomir
Biały 12:39, 10 August 2015 (UTC)

Well, if so, I'll revert it. Boris Tsirelson (talk) 12:49, 10 August 2015 (UTC)

There is also the annoying habit of prefacing every equation with a colon (:). I am not talking about indentation here, but it is in spread use at WP (and unfortunately in the literature). YohanN7 (talk) 12:53, 10 August 2015 (UTC)

Sorry, I do not understand you. In wikitext we start with the colon for indentation, yes; but did you really see the colon in the rendered articles? If so, could you please give us an example? Boris Tsirelson (talk) 13:01, 10 August 2015 (UTC)

Sorry about being unclear. It also does not apply to this article. But you can find articles that say

Newton's second law is:

$f=ma$

instead of

Newton's second law is

$f=ma$.

Ah, yes, I see. Somehow I've imagined this

: $f=ma$

that I newer saw. Boris Tsirelson (talk) 14:40, 10 August 2015 (UTC)

The colon is highly disruptive in the flow of reading. Sometimes, it is okay, but not as a standard as some use it. It is then just grammatically wrong. YohanN7 (talk) 13:18, 10 August 2015 (UTC)

I agree that this is an abuse of punctuation. See, for example, Fourier transform, where every displayed equation is prefaced with a colon, most of which are unnecessary. Even more egregious is Poisson summation formula, which features not only colons before every displayed equation, but colons in bold. I think the MSM should offer some guidance about when and when not to use colons. Sometimes, colons before displayed equations are helpful (e.g., if the resulting sentence would be grammatical with a colon if it were read aloud). For example, the two displayed equations in Fourier transform#Definition. But prefacing every displayed equation with a colon totally defeats the purpose of punctuation. Sławomir
Biały 13:30, 10 August 2015 (UTC)

I guess that non-mathematicians are inclined to treat displayed equations rather similarly to images and tables, as something that accompanies text and cannot sit within a phrase. Boris Tsirelson (talk) 18:51, 10 August 2015 (UTC)

In fact this usage is quite common in writing by bona fide mathematicians, as well. --JBL (talk) 20:13, 10 August 2015 (UTC)

And that would make it right? No way! YohanN7 (talk) 20:34, 10 August 2015 (UTC)

My post includes no content on its appropriateness or correctness. --JBL (talk) 20:41, 10 August 2015 (UTC)

Regardless of appropriateness, it would be nice if we had some guidance from other style manuals. Halmos recommends natural punctuation in mathematics writing, which would argue against a practice of universally colonating displayed mathematics. But if there are other recommendations in the literature, they might give a usefully different perspective. Sławomir
Biały 21:02, 10 August 2015 (UTC)

Krantz, A Primer of Mathematical Writing (pp. 23–24) also recommends natural punctuation and against colonating displayed equations. —David Eppstein (talk) 21:26, 10 August 2015 (UTC)

Is an GA rating higher of lower than a B+ rating ?

On Wikipedia:WikiProject Mathematics/Wikipedia 1.0 the Summary table puts B+ left of GA (higher grade position ) of GA while Quality grading scheme puts B+ below GA (lower grade position ) the summary table seems to be automatically generated so i don't know how to change this, am I correct in this? (also see Mathematics B+ rating at Wikipedia talk:Version 1.0 Editorial Team/Index#Mathematics B+ rating ) WillemienH (talk) 08:47, 1 August 2015 (UTC)

The table is from an included page. One idea would be to include User:WP 1.0 bot/Tables/Project/Mathematics instead. I don't know if the Math project's criteria are consistent with this version though. --RDBury (talk) 02:47, 3 August 2015 (UTC)

Why do you have a B+ rating (which apparently means "probably a GA")? Why not just nominate such articles for GA status like other projects do? Kaldari (talk) 00:59, 4 August 2015 (UTC)

Many years ago, there was the perception that mathematics articles would never be accepted for GA status. GA reviewers need to understand what they read in order accurately assess the article, and mathematics articles, even well-written ones, often require mathematical background that GA reviewers will often not have.

B+ isn't used much. I think while the idea is good in principle, it hasn't really worked out in practice. I wouldn't object if someone were to remark all of those articles as B. Ozob (talk) 02:31, 4 August 2015 (UTC)

Incidentally, there is a bit of a backlog at Wikipedia:Good article nominations#Mathematics and mathematicians, but not one that is out of line with the other categories there. I think we should be pushing more of our articles for good article status. For instance, despite a lingering issue in its subsection on the Lee–Yang theorem, and despite being quite technical, I think Riemann hypothesis is in much better shape than the typical B-class article (I can say this because most of the effort to get it into shape was not mine). We already have a few mathematical good articles (see Wikipedia:WikiProject Mathematics/Recognized content) but they're kind of a random sample rather than really being the best of our articles. So one way that we could clean up this B+ issue would be to look through the list of B+ articles and see whether some or all of them should become good articles instead. (Like Ozob, I wouldn't object to getting rid of B+ as a class.) —David Eppstein (talk) 21:37, 10 August 2015 (UTC)

Some math articles created after Wikipedia:WikiProject Mathematics/Current activity stopped being updated

A list I got by browsing the history of User:AlexNewArtBot/MathSearchResult:

• The Art of Mathematics (series)
• Sub-Gaussian random variable
• Ternary equivalence relation
• Warwick Tucker
• Aperiodic frequency
• Théophile Lepage
• Arthur Preston Mellish
• Yusuf Al-Khuri
• Johanna Weber
• Wilfrid Dixon
• Von Foerster equation (ecology)
• Betz Halloran
• Salvatore J. Stolfo
• Evan William Evans
• Evan Tom Davies
• Marco A. Janssen
• Lawrence Zalcman
• Joseph Delboeuf
• Awele Maduemezia
• Arnold's spectral sequence
• Nikolai V. Ivanov
• Thaine's theorem
• Hoàng Xuân Sính
• Shafarevich's theorem on solvable Galois groups
• Eigenoperator
• Bill Ferrar
• Mathematical sculpture
• Claude Mylon
• J. F. Cameron
• Positive real numbers
• Alex Chigogidze
• Branko Souček
• Keith Stewartson
• Siegmund Guenther
• You-Dong Liang
• Patrick Michael Grundy
• Meyer Dwass
• Shlomo Zilberstein
• Benjamin Bramer
• Liouvillian function
• Interval edge coloring
• Ludwig Staiger
• Branches of geometry
• Max Simon (mathematician)
• Francisco Santos Leal
• Robert Brown Gardner
• Poussin graph
• Étienne Pardoux
• Giovan Antonio Rusconi
• Regular embedding

• Richard Grandy
• Claude Hardy
• Yves Le Jan
• Spiral wave
• Benjamin Kagan
• Diameter of a finite group
• Harald Niederreiter
• Raymond Keiller Butchart
• Polynomial decomposition
• Raymond E. Goldstein
• Negative-dimensional space
• Nguyen Dinh Ngoc
• Hermann Gruson
• Desuspension
• George Murray Burnett
• Cirquent calculus
• Optimistic knowledge gradient
• Princeton International School of Mathematics and Science
• César Camacho
• Chia-Kun Chu
• Sverdrup Prize
• Giovanni Forni (mathematician)
• List of Brazilian mathematicians
• Theodore Strong
• José Felipe Voloch
• Shambhu Dayal Sinvhal
• Robert B. Schnabel
• Alexander G. Burgess
• Universal representation (C*-algebra)
• Ernesto Lupercio
• Lê Thị Thanh Nhàn
• Glaeser's continuity theorem
• Kolmogorov–Arnold representation theorem
• Ronald J. Stern
• Briggs–Bers criterion
• Valeria de Paiva
• John Watt Butters
• Abdias Treu
• Revision Theory
• Yuguang Shi
• Topological functioning model
• William Trail
• Lasse Rempe-Gillen
• How to Bake Pi
• C. Dianne Martin
• Toda-Smith complex
• Global mode
• Frank Beck (computer scientist)

I think that here are listed approximately 30% of the math articles created after 15 June. Dertemivivahirry (talk) 07:06, 28 July 2015 (UTC)

Thanks! You might get a more comprehensive listing from User:Mathbot/Changes to mathlists — Mathbot still seems to be running even though Jitse's bot isn't. —David Eppstein (talk) 07:20, 28 July 2015 (UTC)

Looking at the more comprehensive listing I observe that (at least) "X+Y" and "Exaggeration" should not belong... Boris Tsirelson (talk) 18:45, 28 July 2015 (UTC)

I think X+Y does belong, at least as much as the contents of Category:Mathematics fiction books (it's a movie about the International Mathematical Olympiad — I enjoyed watching it). But there are also some articles on ceramic tiles that definitely don't. —David Eppstein (talk) 19:17, 28 July 2015 (UTC)

By the way, does "Mathematical elimination" belong? Boris Tsirelson (talk) 07:23, 12 August 2015 (UTC)

Jacobian conjecture

I have suggested a modification to the article describing the birational and Galois cases. See Talk:Jacobian conjecture#The birational and Galois cases. As usual, will need help on this.

L.Andrew Campbell (talk) 18:27, 13 August 2015 (UTC)

Kelvin–Stokes theorem

On the talk page, I have provided a more elementary, though admittedly less elegant, proof of the theorem, that is much more easily understood by elementary vector calculus students.

Generally, though, I think this article could use a lot of work (as many of you probably do). It should discuss some physical applications of it, such as the equivalence of the differential and integral forms of the 3rd and 4th of Maxwell's equations.--Jasper Deng (talk) 10:01, 14 August 2015 (UTC)

Troublesome editor

[This here] concerns the math project as well, since Cuzkatzimhut (and also I) edit both math and physics articles. YohanN7 (talk) 13:24, 15 August 2015 (UTC)

I'm not generally a fan of these refimprove templates. Often they are clearly wrong, and occasionally they can be disruptive, especially when there is disagreement about how many references are enough. An easy solution that avoids most of the drama is to add a footnote or two, and then remove the template. Sławomir
Biały 14:13, 15 August 2015 (UTC)

It might be a vast improvement if the templates were reconfigured to go to the Talk pages, instead. They are frequently used for political purposes and by frustrated readers who decide to deface the entire page with ref templates, in the vague hope something they may lack the training to understand will lead them to the mother load reference that makes everything clear. Instead, 8 times out of 10, it is the WP article which is clearest. Cuzkatzimhut (talk) 18:57, 15 August 2015 (UTC)

Policy on red-linked personal names in Math articles

In a recent edit, an IP user added yet another red linked item to the list of doctoral students in the infobox at Grigory Margulis. Do we have any policy in place regulating such matters? My own feeling is that infobox should not serve as a replacement for Math Genealogy or person's scientific biography (and bibliography), and in this case the list is already excessive (and also inaccurate). Personally, I would even be hesitant to add red linked names which are not likely to get their articles per our interpretation of WP:Notability to the main text. Arcfrk (talk) 04:57, 14 August 2015 (UTC)

Re the students to list in infoboxes: my preference would be to include only bluelinks. As for whether to redlink names elsewhere in the article: Wikipedia:Red link says to do it when you believe the subject of the link to be notable even though no article exists, and I think that's a pretty good rule. —David Eppstein (talk) 05:07, 14 August 2015 (UTC)

Thank you, David. Obviously, you and I are in agreement on this, but it would be nice to have a policy or a guideline addressing this issue (for infobox). In this particular instance, I have cleaned up the infobox, removing redlinked former students and two redlinked prizes. Arcfrk (talk) 04:14, 16 August 2015 (UTC)

Input needed

A recent dispute over content in List of female mathematicians escalated to the point where the page was protected; see Talk:List of female mathematicians#Joshi edit-warring and more general issues of line length and image inclusion and following sections. Input from more editors would be welcome. RockMagnetist(talk) 03:25, 19 August 2015 (UTC)

Related to this, there is a new discussion starting over who should be included in the "mathematician" categories. Please see Talk:List of female mathematicians#Who is a mathematician? and contribute your opinions. —David Eppstein (talk) 17:59, 20 August 2015 (UTC)

Algebra over a field -> Algebra (mathematical object)

I was thinking of renaming Algebra over a field to Algebra (mathematical object), and also merge Algebra (ring theory) in there as well; then we could make it a WP:CONCEPTDAB. The concept of an algebra is fairly standard, apart from whether or not we assume unital / associative / commutative / finite-dimensional / over a field / over a commutative ring.. Basically an algebra is something that has an binary addition, binary multiplication, and a scalar multiplication of some kind. Since many readers probably don't quite know what they are looking for, and the precise definitions depend on the sources, I think we should have a broad concept article that covers all "algebras".

We also have Non-associative algebra and Associative algebra. I suppose a Nonassociative ring is trivially an algebra over Z, so we could naturally merge that article into Non-associative algebra.

Any objections to any of the above? Mark MacD (talk) 11:41, 18 August 2015 (UTC)

I'm skeptical of these types of merges. The problem is that objects which share formal similarities may appear in very different contexts, and merging can create an incoherent mess. Algebra over a field is already an impossibly broad topic, and besides, it would plainly be inadvisable to try to create an article on everything in mathematics called an "algebra". Would this article also subsume the article vertex operator algebra, whose subject is neither of those things? --Sammy1339 (talk) 03:06, 19 August 2015 (UTC)

Thanks for the reply; fair point about vertex algebras, but as I understand it, they are not considered to be "algebras". I still don't think Algebra (ring theory) should be a separate article. Someone else has tagged Algebra (ring theory) with a merge tag, and I would like to merge its content elsewhere. The most common mathematical concept of "an algebra" is not impossibly broad; I have just expanded on the brief explanation in the even-broader concept article called Algebra. Mark MacD (talk) 09:12, 19 August 2015 (UTC)

We have vector space as a separate article even though it is a special case of module (mathematics). This is how we do things in Wikipedia, even if that is against Bourbaki's style. This makes sense from the pedagogical point of view since students learn elementary topics before advanced topics (I know "topos" is more elementary than topological space but that's another issue).

It is true that algebra (ring theory) is underdeveloped; I think the article title is not helpful for fostering healthy development. What matters with these objects are really whether they are associative or not. Thus, it's better to have two articles associative algebra and nonassociative algebra and spread materials accordingly . -- Taku (talk) 23:39, 19 August 2015 (UTC)

Taku, you were the one who added the merge tag to algebra (ring theory) in the first place! :-) I agree we should keep associative algebra and non-associative algebra separate from each other. Mark MacD (talk) 12:21, 20 August 2015 (UTC)

Yes, I think I wasn't clear about my position :) My proposal would be to have the three articles, and only those three, that are devoted to the topic of "algebra": (1) algebra over a field (2) associative algebra and (3) non-associative algebra. (1) covers both associative (e.g., a ring that is a vector space) and non-associative (e.g., Lie algebra) algebras, while (2), (3) are over an arbitrary (commutative) ring. There are going to be considerable overlaps between (1) and (2), (3). But I think that's ok for the reason mentioned above (mainly the pedagogical reason and here in Wikipedia we don't necessarily strive for the the strict implementation of the Bourbaki style). -- Taku (talk) 12:42, 20 August 2015 (UTC)

I see; we're pretty much on the same page then. I've just merged Algebra (ring theory) into Algebra over a field. Somebody might like to check it. Cheers, Mark MacD (talk) 09:41, 21 August 2015 (UTC)

RfC on definition of a mathematician

I started an RfC here on the issue mentioned by User:David Eppstein above. --Sammy1339 (talk) 00:26, 22 August 2015 (UTC)

In other words, the discussion at Talk:List of female mathematicians has turned against Sammy, so he's going forum-shopping in hope of getting a more favorable audience. —David Eppstein (talk) 00:39, 22 August 2015 (UTC)

I'm not forum-shopping. The issue is obviously broader than that topic so I posted it at what I thought was the appropriate place. I linked to that discussion from the original one - I'm not hiding anything. --Sammy1339 (talk) 00:42, 22 August 2015 (UTC)

Order of a polynomial nominated for deletion

I have nominated for deletion Order of a polynomial. See Wikipedia:Articles for deletion/Order of a polynomial. D.Lazard (talk) 10:56, 24 August 2015 (UTC)

AfC submission

What do you think of Draft:Biweight midcorrelation? Best, FoCuS contribs; talk to me! 18:59, 26 August 2015 (UTC)

Bilingual glossaries: For translating content about elementary through high school-level mathematics

Dear Wikipedians,

I found some glossaries that can be useful in translating material about mathematics at the elementary and high school levels: http://www.p12.nysed.gov/biling/bilinged/bilingual_glossaries.htm WhisperToMe (talk) 16:38, 31 August 2015 (UTC)

Exponential type

Can someone answer my question at Talk:Exponential type? Eric Kvaalen (talk) 09:13, 31 August 2015 (UTC)

Yes we did. Boris Tsirelson (talk) 10:10, 31 August 2015 (UTC)

Oops, no, sorry; we did not! Experts in complex variable are needed... Boris Tsirelson (talk) 15:21, 31 August 2015 (UTC)

Probably, the question is already solved by Eric Kvaalen himself! Boris Tsirelson (talk) 17:27, 31 August 2015 (UTC)

Sep 2015

ICM speaker category deletion discussion

Please see Wikipedia:Categories for discussion/Log/2015 September 2#Category:ICM Plenary and Invited Speakers by year and contribute to the discussion. —David Eppstein (talk) 17:36, 2 September 2015 (UTC)

Jitse's bot

Since Jitse's bot stopped updating the new articles list on the current activities page I've participated a lot less in Wikipedia. He said in an email to me not long after the situation arose that he'd look into it. The last new-articles update was on the 15th of June. Is it possible for others to take over the bot --- perhaps for everyone who knows how to run it to be permitted to contribute to running it? Michael Hardy (talk) 20:33, 2 September 2015 (UTC)

It would be nice if there is some documentation on how the process works; in hindsight the problem was a lack of such documentation (because other editors can't just take over the bot.) I'm "willing" to take over but I need to know more about the bot, like where it is running. -- Taku (talk) 21:19, 2 September 2015 (UTC)

Some but not all of the bot's activities are duplicated elsewhere. Lists of new articles are still updated at User:Mathbot/Changes to mathlists, and pointers to active deletion discussions can be found at Wikipedia:WikiProject Deletion sorting/Mathematics, so if you watchlist both of those you can stay reasonably up to date. But I miss the updates to Wikipedia:Pages needing attention/Mathematics; that was a helpful way to find pages in need of editing and (by tracking its size) to feel that I was making a difference in the quality of our overall coverage. —David Eppstein (talk) 21:54, 2 September 2015 (UTC)

Wikipedia:Articles for deletion/Order of a polynomial‎

This AfD has been relisted for the second time. Please, comment there in order to reach a sufficient consensus. D.Lazard (talk) 08:37, 8 September 2015 (UTC)

Conversion between units of angle

I've suggested at Template talk:Convert that {{convert}} support conversion between units of angle (ie. degrees of arc, arcminutes, radians, gradians, etc) ; what do you guys think? -- 70.51.202.113 (talk) 05:07, 7 September 2015 (UTC)

Much of the time when one specifies an angle (at least in a mathematics article) one wants an exact formula for it, not a numerical approximation. E.g. one is more likely to write (and want to read) 90° or π/2 radians rather than 90.0 degrees or 1.5707963267948966 radians. Exactly how do you propose to support the conversion of such formulae? —David Eppstein (talk) 06:57, 7 September 2015 (UTC)

I was thinking of using the numerical approximation for the conversion formulae, instead of the pi-fractional-value, for radians. CONVERT already uses significant figures by default, so that would come out with round degrees. Identifying the pi-fractional-value on the other end would take out the pi from the value returned such as by {{expr|value/pi}} and then formatting with the appropriate markup; the fraction would still be decimalized -- 70.51.202.113 (talk) 05:01, 8 September 2015 (UTC)

What of conversion between the units in the same sexagesimal system? Degrees of arc, seconds of arc, minutes of arc, sub-second metricized units of arc (ie. milliarcsecond) -- 70.51.202.113 (talk) 05:03, 8 September 2015 (UTC)

So 90° would convert to 0.5π rather than π/2? Hmm. The 0.5π is not technically wrong, but it feels culturally wrong. And 60° would convert to something like 0.33π, rather than π/3? Such approximation is not desirable in pure math articles, although it might be useful in other articles. Mgnbar (talk) 08:29, 8 September 2015 (UTC)

But I think this reply misses the point. An expression like pi/3 doesn't have just one or two significant figures, but rather infinitely many. How would the proposed template ascertain this, and what would its behaviour be in such cases? Sławomir
Biały 11:10, 8 September 2015 (UTC)

The anonymous poster is motivated by astronomical data. Such a conversion could be useful in astronomy articles. We would be under no obligation to use it in pure math articles (right?).

In some sense mathematicians are the wrong audience for such a question. Geographers, physicists, engineers, etc. would be more appropriate. Mgnbar (talk) 11:58, 8 September 2015 (UTC)

I've no real objection to using it is, e.g., astronomy articles. But I find the case that it is actually useful even there rather hypothetical at the moment. Although it is certainly true that just because something exists doesn't mean it must be used, templates like this do have a way of being applied in contexts we would regard as inappropriate. Claims that we can convert radian measures involving pi to other units are not exactly encouraging. They strongly suggest that this proposal hasn't really been thought through, nor that actual applications of the template will take much of a nuanced view of things. Something vaguely like WP:BEANS is relevant here. If someone is knowledgeable enough to apply the template correctly, they are knowledgeable enough to do conversions if they are appropriate for the article. There are other ways of including the original value if necessary than through this template: footnotes, inline comments, parenthetical notes, erc). 12:30, 8 September 2015 (UTC)

Fractional conversions seems like an over-engineering. In sciences, when you use 'fractional pis' like π/2, you mean an exact angle. Anyone writing π/2 would also know this is 90°, and the conversion can be done manually if it's relevant. When it used to express measurements, you report them in decimal form e.g. (89°±2°, or 1.553±0.035 rad). If {{convert}} handles the later case (likewise for seconds, arcseconds, etc.), that's all it should do. Headbomb {talk / contribs / physics / books} 12:44, 8 September 2015 (UTC)

Perhaps it would be useful for the template to explicitly refuse to support conversions to and from radians. As far as I'm aware, radians are used almost exclusively by people who are comfortable with rational multiples of π, and in those situations the conversion can be done by hand.

It's also undesirable for the template to try to recover the appropriate rational multiple of π, because while the recovery is easy, the result is unhelpful. Converting 45.172°±0.649° to radians should not give 529782818665573π/2111062325329920 ±730709039540863π/202661983231672320 rad, because it's wrong (these huge expressions are because 45.172 and 0.649 are not exactly representable as floating point numbers); it shouldn't give 11293π/25000 ±649π/1000 rad because, while accurate, it's hard to read; and it shouldn't give π/4 ±0 rad because it's wrong.

As a third comment, {{val}} (which I initially hoped to use in the previous paragraph) does not support fractions; I'm sure there are other templates out there that don't support fractions and certainly not rational multiples of π. Wikipedia's template infrastructure isn't set up for symbolic manipulations that support for rational multiples of π would require. Ozob (talk) 14:26, 8 September 2015 (UTC)

Styling of block mode display of math formula

The latest version of the <math> extension now supports a <math display="block">...</math> mode to display equation in a display rather than inline style. Visual Editor is offering this mode and does not seem to allow the :<math>...</math> formatting which is the standard here.

Currently this mode centres the equations and hence clashes with the standard single indent style used in this wiki and most of the other wikis I've checked.

I've a bit of CSS

.mwe-math-fallback-image-display,
.mwe-math-mathml-display {
    margin-left: 1.6em !important;
    margin-top: 0.6em;
    margin-bottom: 0.6em;
}
.mwe-math-mathml-display math {
    display: inline;
}

which seems to make these equations display left aligned indented one space so it matches the other equations. I've checked this in PNG/SVG and MathML modes on a mac but not on mobile. We could potentially add this to MediaWiki:Common.css or possibly make it the global default in ext.math.css.

I've raised this at Wikipedia:VisualEditor/Feedback#Indentation for mathematical equations and created a task T111712 (which someone has helpfully closed).--Salix alba (talk): 17:05, 8 September 2015 (UTC)

Discussion about whether to deprecate Template:Cite doi

Template:Cite doi allows editors to generate a citation from a digital object identifier. There is a discussion about whether to deprecate this template. Since doi's are used the sciences and this is a science WikiProject, I am inviting anyone here to comment. Blue Rasberry (talk) 14:25, 9 September 2015 (UTC)

Notation for super-exponential functions

There is a group of related concepts involving fast-growing arithmetic functions, for which our article seems to be at hyperoperation (I am not sure how standard this name really is, but that's not my immediate concern). There are lots of different notations detailed there.

Anyway, there's an IP editor, editing as User:101.14.227.116 and User:101.14.37.226 (and perhaps other addresses but I haven't seen them), who seems to have decided that one particular notation, the ASCII version of the "box notation", is the one that should be used. That notation appears in the references of the hyperoperation article with references no earlier than 2005, whereas other notations are dated much earlier. I see no evidence that the box notation has become standard (particularly in its ASCII variant).

I want to emphasize that I have nothing particularly against the box notation. It does seem a bit "neater" visually than the Knuth up-arrow notation that Wikipedia seems to have favored up to now. But I doubt that it is very much used in the wild (I would be interested to hear evidence either for or against this proposition), particularly in its ASCII variant. And procedurally, I don't think we can allow an editor to come in and make a broad change of notation without discussion. --Trovatore (talk) 16:26, 10 September 2015 (UTC)

Missing mathematics journals

As a follow up to Wikipedia_talk:WikiProject_Mathematics/Archive/2011/Jul#WP:JCW_and_mathematics, and the recent update to WP:JCW, here are the top-cited missing journals of mathematics.

Main pageDiscussionContentAssessmentParticipantsResources

Top-cited missing journals:

• Aequationes Mathematicae
• Annals of Pure and Applied Logic
• Astat info
• Combinatorics, Probability and Computing
• Congressus Numerantium
• Czechoslovak Mathematical Journal
• Discrete Applied Mathematics (11th missing journal!)
• Forum Geometricorum
• Illinois Journal of Mathematics
• Journal of Applied Probability
• Journal of Computational and Applied Mathematics
• Journal of Geometry
• Journal of Integer Sequences
• Journal of Optimization Theory and Applications
• Journal of Mathematical Analysis and Applications
• Journal of Mathematical Sciences
• Mathematika
• Nagoya Mathematical Journal
• Russian Mathematical Surveys/Russian Math. Surveys
• SIAM Journal on Applied Mathematics (see Category:SIAM academic journals)

Like previously mentioned in the old thread, there's also Proceedings of the London Mathematical Society which currently redirects to London Mathematical Society, but should really get it's own article. Same for the Bulletin of the London Mathematical Society and the Journal of the London Mathematical Society, which also redirect there. Journal of Algorithms seems to have a less-than-boring history, considering the board resigned en-masse at the behest of Donald Knuth as a way to protest the Elsevier prices. They went on to establish the ACM Transactions on Algorithms. See [32][33] for some sources on this, as well as the current content in the Elsevier article.

See WP:WikiProject Academic Journals/Writing guide for guidance, and don't forget to add them to List of mathematics journals once they are created. Many thanks for all the help you can give us. Headbomb {talk / contribs / physics / books} 13:58, 24 August 2015 (UTC)

@CBM:, is your journal article script thing still available? Headbomb {talk / contribs / physics / books} 19:18, 26 August 2015 (UTC)

The journal article creation tool is defunct. It was a script in my web directory on the toolserver, which was decommissioned. I don't believe I have any copy of the source. But it was really just a small script to take information in a web form and format it into an article. I don't have enough time for web development these days, but a competent programmer could do it very quickly given a model of the articles that are being created. — Carl (CBM · talk) 23:20, 28 August 2015 (UTC)

Is Congressus Numerantium really a journal? It looks like a book series to me. In any case I can't find enough independent in-depth coverage of it to start even a stub. —David Eppstein (talk) 22:33, 29 August 2015 (UTC)

It is really a journal in format, rather than a book series. I have a recent volume on my office shelf. However, I agree that there is not likely to have much independent coverage. I have the vague impression that journal used to publish more, but recently has been primarily publishing conference proceedings. — Carl (CBM · talk) 00:43, 30 August 2015 (UTC)

'Journals', in the sense of my original post (and in the sense of WP:JWG), refers to journals, monograph series, conference proceedings, etc... If it's notable in the sense of WP:JOURNALS, then it's likely enough to keep/have an article around. An alternative is to have it redirect to the publisher, and have a section in the publisher's article about Congressus Numerantium . I'm not familiar with that publication, so I don't have any specific recommendation about which of the two is the best course of action. Headbomb {talk / contribs / physics / books} 01:13, 30 August 2015 (UTC)

I have some fond memories of Congressus Numerantium, and have several early career articles published in it. From the 1992 (Vol. 89) frontspiece we have that it is "A Conference Journal on Numerical Themes" and that there are two subseries: 1) The Southeastern Conference on Combinatorics, Graph Theory, and Computing and 2) the Manitoba Conferences on Numerical Mathematics and Computing. Besides these subseries, other volumes have been published. The publisher is Utilitas Mathematica Publishing Incorporated which I believe is associated with the University of Manitoba. The guiding force behind the journal and Utilitas (I think) was the late Ralph G. Stanton of the University of Manitoba. The journal has its own ISSN number, but each volume has its own ISBN, which is probably why it looks like a book series. Bill Cherowitzo (talk) 03:00, 30 August 2015 (UTC)

@Bill Cherowitzo: Care to take a stab at it? Headbomb {talk / contribs / physics / books} 18:22, 8 September 2015 (UTC)

I've moved the list to a separate page, linked above, so that it will persist when this page is archived, and can be more easily linked-to. Andy Mabbett (Pigsonthewing); Talk to Andy; Andy's edits 12:42, 11 September 2015 (UTC)

orphans!

The list of WiMAX networks included Spectral Networks, which offers services near the Iowa–Missouri border in both states. Clicking on that, one found the article titled Spectral Networks, on a topic in Riemannian geometry. I moved that to Spectral network with a lower-case initial "n" and no final "s" (and did some obvious copy-editing), and then changed Spectral Networks with a capital "N" and a final "s" into a very very stubby article about the company, with a disambiguating hatnote linking to the geometry article. Hence the geometry article is now an "orphan" with no other articles linking to it. So one problem is: which other articles should link to it?

But more generally: what should we do about the fact that lots of new math articles are orphans? Mathematicians doing the one and only Wikipedia edit of their lives create a new article and almost always [no pun intended] it does not occur to them that other articles should link to it. Michael Hardy (talk) 17:17, 12 September 2015 (UTC)

I believe the standard way to solve this problem is to create a stub before not-so-active editors start an article and never bothers to have links to it elsewhere in Wikipedia. The other effective solution is to create link farm-type articles; like glossaries or lists of award recipients. Ideally those articles have a lot of red links and so we can preemptively prevent orphanage from occurring. (By the way, red links are thus very important; it's puzzling to me some editors find having red links is somehow the evidence of deficiency, which really isn't.) -- Taku (talk) 00:02, 13 September 2015 (UTC)

{{PlanetMath}}

template:PlanetMath has been proposed fro deletion -- 70.51.202.113 (talk) 06:22, 16 September 2015 (UTC)

Merge row vector and column vector

Both of these article are short, similar, have clear overlap, and the references are even similar. Any good reasons not to merge?

Another triplet to consider is row space, column space, and row and column spaces. M∧Ŝc²ħεИ_τlk 19:20, 16 September 2015 (UTC)

I would merge them. Michael Hardy (talk) 20:17, 16 September 2015 (UTC)

Sounds sensible.TR 20:26, 16 September 2015 (UTC)

I agree. --JBL (talk) 20:36, 16 September 2015 (UTC)

Me too. There's no point in having symmetrical pairs of articles like this when one will do. —David Eppstein (talk) 20:38, 16 September 2015 (UTC)

I would also do it that way. Noticed that the "space" articles had been split out of the row and column spaces article in 2007 by a reasonable editor but without any reasons given. I'd be curious to know what those reasons were since I can't imagine a convincing justification. Bill Cherowitzo (talk) 20:45, 16 September 2015 (UTC)

The row and column vector articles are now merged. Now merging the separate space articles into one. M∧Ŝc²ħεИ_τlk 22:55, 16 September 2015 (UTC)

A draft at AFC needs help

Please help review Draft:Kinds of abundant numbers. If you don't wish to, or don't know how to, do a formal AFC review please post your comments on the draft's talk page. Roger (Dodger67) (talk) 14:16, 18 September 2015 (UTC)

Integer complexity

Is the new (and currently orphaned) article titled Integer complexity worth having? (It has a page in OEIS, but I think that alone is not enough evidence of notability.) Michael Hardy (talk) 18:23, 21 September 2015 (UTC)

Platonic solid popcult

Is the new "popular culture" section of Platonic solid justified to include, and does it actually report neutrally and accurately on the popular-culture aspects of platonic solids? Another editor and I have a disagreement. —David Eppstein (talk) 14:29, 21 September 2015 (UTC)

I agree that it doesn't belong there. It is not referenced to any secondary sources, which makes it impossible to determine the relative WP:WEIGHT to assign such content in relation to the rest of the article, but given the vast reams that have been written on the subject of the Platonic solids, my feeling is not much. Platonic solids have enormous cultural and historical significance (e.g., Mysterium Cosmographicum), which makes me think that for a place in the article, we should really demand multiple high quality secondary sources. Also, a plot summary of a book of relatively minor importance seems very inappropriate tone for an encyclopedia article, at least on a serious mathematical topic. Sławomir
Biały 14:41, 21 September 2015 (UTC)

In its current form, it's not good enough to include, but I suspect with some library research one could write a reasonable "popular culture" section in that article. Michael Hardy (talk) 18:26, 21 September 2015 (UTC)

Paul Cohen move

The article on Cohen the mathematician was moved in 2006, unilaterally/inappropriately. I have started a requested move, see Talk:Paul Cohen (mathematician)#Requested move 21 September 2015. Solomon7968 18:22, 23 September 2015 (UTC)

IP address editing at Talk:Jacob Barnett

*This* would be a suitable reward, for saving that videogame from AfD. I do believe the BLP-human in question owns such an item, in fact, or a close fascimile thereof.... Ahem, ping User:Aviators99, when can I expect delivery of my just compensation?

The article Jacob Barnett is back. This time, an IP is arguing there that sources like the BBC breakfast, which place a Nobel Prize in the young Barnett's future, are reliable sources for theoretical physics. Please comment at Talk:Jacob Barnett. Sławomir
Biały 19:39, 20 September 2015 (UTC)

Possibly off-topic here, but the IP's talk page, in which the same IP appears to be working to help other editors game the Wikipedia conflict-of-interest noticeboard for articles including Dunnet (video game) (COI editor Ron Schnell) and NTA (company) (COI editors including Dtompos, NTAInc, and Wscribner), makes enlightening reading. —David Eppstein (talk) 19:50, 20 September 2015 (UTC)

What do you mean "game"? They explained to me why I should not edit the article directly and flag as COI on the Talk page so that it would go in the queue. So far it's been in the queue over a month (a one sentence change). I would hardly call this "gaming". I would say it's the opposite. Ron Schnell 23:46, 22 September 2015 (UTC)

David means WP:GAME. Common way to get people out of your way on wikipedia, is to find something they are doing wrong, and topic-ban them (or just global-ban them). That is an example of WP:GAMEing the system; whereas by contrast, what I do with the wp-coi-queue is perfectly within policy, both letter and spirit. Speaking of which, while I'm here, I'll go ahead and pull some WP:IAR, and say that my wiki-buddy User:Aviators99 aka Schnell aka the DUNNET guy, is *still* waiting for some neutral eyeballs to help him out. He's been in the edit-queue over a month now, nudge nudge, if anybody wants to spend five minutes and mainspace his request, over on said videogame's talkpage?

  p.s. I too, nearly apprehended the orangemoody mastermind, which is how I got involved with NTA... please see here,[34] where I just about screwed the pooch, but thankfully stopped shy of mistakenly accusing an OTRS volunteer of being the sockmaster!  :-/ Though I believe that User:samtar has forgiven me now, mostly.  :-)     p.p.s. David forgot to ping User:Wscribner (active), User:Dtompos (mostly inactive), User:NTAInc (not active and a violation of username policy in any case). Ron found his own way here through his custom crawler app, or through his wiki-stalking my edits as his mentor, I'm not sure which, so no harm done there, and now that all the wiki-gossip has been laid bare, all is well in the wiki-verse... though I must say, that is hardly a wikiproject notification that could in any way be considered WP:FULLYNEUTRAL. 75.108.94.227 (talk) 19:07, 24 September 2015 (UTC)

Perhaps you could explain how you found this editor and why you look so specifically to their advice for guidance on this issue. —David Eppstein (talk) 15:43, 23 September 2015 (UTC)

I learned of the editor's existence during the AfD discussion. They were suspicious that I might be "meat-puppetting" and asked me some questions on my talk page. This led to some questions back and they offered advice, especially on how I should not be editing COI articles in the mainspace, which led to what you've described, which was for me to flag my one sentence requested change for review on August 14. And nobody else has offered me advice (other than one person whose advice was to delete the article), and I'll always take advice wherever I can get it. Ron Schnell 18:30, 23 September 2015 (UTC)

Ok, thanks, that makes sense and is reassuring. I was trying to find a way to allay my suspicions of paid consulting and your explanation does that. —David Eppstein (talk) 18:48, 23 September 2015 (UTC)

Lots of suspicion around here! :-O I guess it's from experience. :-( Ron Schnell 19:09, 23 September 2015 (UTC)

Not to mention... dunnet?

>eat lamp
You forcefully shove a lamp down your throat, and start choking.
You are dead.
You have scored 0 out of a possible 90 points.

I don't think COI is really all that much of a concern here :-D Sławomir
Biały 19:12, 23 September 2015 (UTC)

See the gameplay-snippet still on usertalk, starting with the bit about "eat boulder" in the |quote= param of the offline MacAddict 2003 cite. There was also one videogame reviewer that attempted to "punch tree". Too much violence in video games#Scientific_debate, eh?     75.108.94.227 (talk) 19:07, 24 September 2015 (UTC)

Speedy deleting without Afd

See Wikipedia:Deletion_review/Log/2015_September_27#Sucharit_Sarkar. Solomon7968 20:35, 27 September 2015 (UTC)

Andy Liu

Our article on mathematician Andy Liu recently survived a deletion discussion, but now there's a discussion on what content to include in the article that could use additional participation. See Talk:Andy Liu for details. —David Eppstein (talk) 18:37, 28 September 2015 (UTC)

Euclidean space

The Euclidean space article is popular, ([35]) important and is fairly long. However, it is still not verified at least since 2013. Perhaps we should start working on it and add the inline citations for verification. I had the idea to come here to warn you guys about that issue after reading the edit summaries.

I would add the citations myself but I'm definitely going to need some help... Huritisho (talk) 22:43, 25 September 2015 (UTC)

I am wondering why this article is so popular, it is a rather hi brow math subject. I think it is because some links link to this page while they should link to more basic (low brow)/high school mathematics) pages, like Three-dimensional space (mathematics), solid geometry or maybe other more basic geometry pages. Maybe we should rename the page to Euclidean n-Space and have Euclidean Space to be about one of the more basic geometries WillemienH (talk) 17:40, 27 September 2015 (UTC)

your English is confusing to me. What are you trying to say? Huritisho (talk) 18:33, 27 September 2015 (UTC)

Yes, the article needs references and other improvements. Let me just remark that this has been one of the most contentious articles in my Wikipedia experience. It is about a technical math subject, but one that interacts with school math curriculum, physics, history, etc. So editors from different backgrounds can argue a lot. (Example issue: Did Euclid work on Euclidean spaces?) So, if you're going to work on this article, be prepared for hard work. Mgnbar (talk) 18:47, 27 September 2015 (UTC)

A good high brow reference is the text "Geometry" by Marcel Berger. I have no idea what a good non technical introduction is, but it should be possible to summarize in a way that is meaningful to most intended readers of the article. I don't have time right now, but I may take a crack at it later. The references certainly need improvement. Sławomir
Biały 18:56, 27 September 2015 (UTC)

Sorry I was tired when I wrote my remark. My point is that I think most visitors to the article are looking for something more basic geometry than what the page is offering. I think that most visitors think they will get an article that is about (high school geometry like) Three-dimensional space (mathematics) euclidean geometry solid geometry and so on , while the article is more about the academic subject of n-manifolds where the parallel postulate holds.

For Euclid he did do solid geometry see Euclid's Elements Books 11 through to 13 (Should we not have a article for every group of books of the elements?) WillemienH (talk) 10:56, 28 September 2015 (UTC)

" the article is more about the academic subject of n-manifolds where the parallel postulate holds." I'm certain this is not true. The article is about the standard real coordinate space, with its natural distance function. I don't know whether that can be made accessible to someone with "high school geometry", but it is the subject of the article. We should try to make it as accessible as possible, but not at the expense of changing the subject matter to suit who we think will be in the audience. Our most important obligation is to make sure the article is not wrong. Other considerations to do with audience are secondary.

One thing that needs clarifying is that there are really at least two things that are called Euclidean space in the literature: one is a real inner product space, and the other its underlying affine space. There is yet a third thing that is often conflated with Euclidean space, and that is R^n equipped with the dot product. While such nuances might seem trivial, they actually do matter. The Euclidean space is what's left of the real coordinate space when you've forgotten the coordinate system, but still know how to compute the inner products of things. You can try to simply this description for as low-level an audience as you like, but it still has to be made clear from the beginning. Sławomir
Biały 22:00, 29 September 2015 (UTC)

Sucharit Sarkar

Deletion of Sucharit Sarkar is proposed. Michael Hardy (talk) 20:36, 29 September 2015 (UTC)

Really? Where? —David Eppstein (talk) 21:52, 29 September 2015 (UTC)

OK, apparently it's not currently proposed. It was speedily deleted and that was overturned. Perhaps whoever wanted it deleted has retreated. Michael Hardy (talk) 19:53, 30 September 2015 (UTC)

Oct 2015

Proofs, revisited

An editor, SergeyLiflandsky, has been adding proofs to articles on convergence tests. I don't think they add anything of interest to anyone who should be using Wikipedia, but I'd like a second opinion. Articles are:

1. Matrix norm

   Including a proof of a relationship between two matrix norms which follows almost immediately from other results in the article. The (induced) (2,2)-norm is the same as the (Schatten) ∞-norm (noted in the induced norm section) which is bounded by the (Schatten) 2-norm (results from properties of the vector norm) which is the same as the entrywise (2,2)-norm (noted in the entrywise norm section).) I copied the result into the induced-norm section, but I'm not sure it belongs there.

2. Weierstrass M-test

   Including a second proof.

3. Uniform convergence

   Including the proof that a uniform limit of continuous functions in the "Applications to continuity" section. This one might be sufficiently interesting if no other proofs are in the article, as it uses a typical method. However, I believe the proof outline, referring to above as the "epsilon/3" trick, is sufficient. Also, as noted on the talk page, the proof is correct. As an additional note, it doesn't belong in the "Applications" section.

1. Ratio test

   Includes a proof of Kummer's test; but the proof follows from an immediate combination of the results above.

— Arthur Rubin (talk) 17:51, 29 September 2015 (UTC)

I agree with removing the proof from the article uniform convergence, since we summarize that with the "epsilon/3" trick, which suffices.

I don't entirely agree with their removal from ratio test and Weierstrass M-test. In the case of the ratio test, the proof of Kummer's test is valuable to the reader because it gives some meaning to the otherwise very mysterious auxiliary series $\zeta _{n}$. So I would strongly prefer that proof be included. Also, it is not clear to me that Kummer's test follows from the other results (the article asserts that they are all special cases of Kummer's test, suggesting that it is rather the other way around). If that's true, it could be made clearer.

For the Weierstrass M-test, I think the "other proof" that was deleted is much more natural. Prove the uniform Cauchy criterion and use that to establish uniform convergence of the series. That's probably a matter of taste, but I think it's good to have both proofs included. It also gives a good way to work in a link to the Cauchy criterion, and the test itself is given some more tangible meaning as a result. So I think there is definite encyclopedic value in having that. Sławomir
Biały 20:08, 29 September 2015 (UTC)

Arthur here really want to emphasize how brilliant he is and how everything is so obvious to him, but seems unable to understand some obvious things that follow form common sense. He also fails to understand the value of method of the proof. In the proof of Kummer's test the method is emphasized while the proofs above look like tricks. — Preceding unsigned comment added by SergeyLiflandsky (talk • contribs)

1. For matrix norm, I now doubt even the relationship is appropriate, except in a spin-off article relationship between matrix norms. The "proof" that the induced 2,2 norm is less than the elementwise 2-norm is much simpler the way I put it;

   The induced 2,2 norm is equal to the spectral &infty; norm (interesting result, already in the article)

   The spectral &infty; norm is dominated by the spectral 2-norm (follows from properties of vector norms)

   The spectral 2-norm is equal to the elementwise 2-norm (interesting, but already in the article)

2. For Weierstrass M-test, I replaced the proof with the newly added one, and cleaned it up a little. The last step that any "uniformly Cauchy sequence" uniformly converges needs to be added, though. I5 follows from completeness, but not immediately.
3. For ratio test, I can see the point that the proof is not precisely a combination of proofs already in the article, but, if that proof is included, others should be removed.
4. For uniform convergence, after studying the article, I'm sure the proof should not be there. A proof is in uniform limit theorem; I haven't checked whether they are the same proof, and whether possibly a reformmated version of SergeyLiflandsky's proof should replace that one. The proof definitely should not be in the "Applications" section of uniform convergence, and almost certainly should not be in uniform convergence at all.

May I suggest that SergeyLiflandsky's suggestions would likely be appropriate in Wikibooks, and certainly in Wikiversity (if that's still open; there had been an attempt to shut it down.)

— Arthur Rubin (talk) 10:20, 30 September 2015 (UTC)

Only about uniform convergence (the rest can be worked out in the same way, as a textbook might say). Do we really need the article uniform limit theorem? The statement is probably usefully included in the main uniform convergence. I think the proof (that the uniform limit of a sequence of cont func is cont) belongs to the article. It's a very good way to understand the concept of uniform convergence, which can be esoteric to calculus students. I myself learned uniform convergence at the same time as I tried to understand the proof. It would especially be useful to point out exactly how the proof fails if the uniform convergence is weakened to point-wise convergence. The proof that is currently given at uniform limit theorem is correct but not a good one. It's much better to give a more accessible proof (say for real-valued functions on an open interval). The extension to a more general case (say values are in a metric space) is entirely mechanical; we should just say an extension is mechanical and there is no need to give a proof of the general case. -- Taku (talk) 03:19, 5 October 2015 (UTC)

While we're speaking of proofs ...

Category:Articles containing proofs is neither fish nor fowl. It is classified as a maintenance category, but it is not clear what maintenance it enables. It is a hidden category, but is linked from List of mathematical proofs and List of mathematics categories in article space, and it is a subcategory of Category:Mathematical proofs instead of a Wikiproject category. Maintenance categories are mainly for use by maintenance projects, and the categorization guidelines state that articles should be kept out of such categories wherever possible (usually the talk pages are added instead). Generally articles end up in maintenance categories because they are put there by maintenance tags; but the articles in this category are added by hand.

So – does this category serve any maintenance purpose? If so, is there a better way to handle it? I would suggest, at a minimum, relocating it in Wikiproject space and removing mentions of it in article space. RockMagnetist(talk) 23:16, 4 October 2015 (UTC)

At one point it was decided that most proofs in most articles were unencyclopedic. The category is a maintenance category because the articles that had these proofs needed to have them removed, which is essentially a kind of maintenance. I believe it is still the consensus that most proofs that would be included in a textbook or a paper are not sufficiently notable to warrant inclusion in an encyclopedia. However, for the reasons you give, I'm not sure that the category is being handled properly. I agree that it would be good to move it to Wikiproject space and to put talk pages into the category instead of articles. Ozob (talk) 00:13, 5 October 2015 (UTC)

Ultimately, Wikipedia is what the editors want it to be. We (the editors) certainly don't want errors or other inaccuracies in the articles, but I'm not sure if the proofs are equally something that needs to be actively removed. It is probably a stretch to apply the notability criterion to the proofs since the criterion is mainly a mechanism to keep away articles on nobodies and other non-notable sports teams, bands, etc. The notability criterion does not and should not apply to calculations. The proofs should be treated similarly. Some routine proofs are probably not illuminating just as any routine computations are boring. But the decision should be made case-by-case.

Oh, about the category in question: the corollary of what I said is that there is no need for a category like that since an article doesn't mean anything from the maintainance point of view. -- Taku (talk) 00:53, 5 October 2015 (UTC)

The discussion surrounding proofs in Wikipedia articles is as old as Wikipedia itself, see Wikipedia talk:WikiProject Mathematics/Proofs. As far as I can see there's no consensus on whether a consensus ever was reached in this discussion, so to speak. – Tobias Bergemann (talk) 07:42, 6 October 2015 (UTC)

AfC submission 04/10

See Draft:Spectral Correlation Density. Thank you, FoCuS contribs; talk to me! 01:00, 5 October 2015 (UTC)

• Also Draft:Geometric set. FoCuS contribs; talk to me! 17:12, 9 October 2015 (UTC)

Group theory terminology

• Group theory terminology (edit | talk | history | protect | delete | links | watch | logs | views)

On 8 October 2015 this was moved from Glossary of group theory. It has now been nominated for deletion. Johnuniq (talk) 02:31, 10 October 2015 (UTC)

Can we just merge it with group theory? -- Taku (talk) 03:38, 10 October 2015 (UTC)

Draft at AFC needs help

Please help review Draft:Geometric set. If you do not know how to, or don't wish to do a full AFC review, please post your comments on the draft's talk page. Roger (Dodger67) (talk) 09:29, 13 October 2015 (UTC)

Complex affine space → complex coordinate space

Please comment regarding the proposed move at Talk:Complex_affine_space#Requested_move_13_October_2015. Sławomir
Biały 14:17, 13 October 2015 (UTC)

Template:Isaac Newton

I seem to have bitten off a bit more than I can chew in creating {{Isaac Newton}}. Are there any experts on the relevant subjects that could help to sensibly organize the template.--TonyTheTiger (T / C / WP:FOUR / WP:CHICAGO / WP:WAWARD) 17:59, 9 October 2015 (UTC)

• I have cobbled together what I can for this template. It would help to have eyes on it. It would likely benefit from rearranging by an expert.--TonyTheTiger (T / C / WP:FOUR / WP:CHICAGO / WP:WAWARD) 19:16, 13 October 2015 (UTC)

Dihedral angle

Can some persons more knowledge than me have a look at Dihedral angle? I did some edits but it needs attention of a proper geometer , the article is a bit a mix of the same angle in mathematics, computing, chemistry and biology. and the math/ geometry bit is underdevelopped. (the main formula looks to be comming from a computing manual , not from a proper math book) WillemienH (talk) 11:00, 14 October 2015 (UTC)

Flowchart on wiki

This isn't precisely mathematics, but I figured that this group would know: Is there a way to create a flowchart on wiki? Or a set of templates that mimics it?

I want to be able to create some decision trees for a few templates. They would say things like this:

Should you use this template?

• Is there currently a problem with neutrality in this article?
  • No: Then don't use it.
  • Yes: Then see the next question.
• Is the neutrality problem caused by an editor with a COI?
  • No: Then don't use this one. Use plain old {{POV}} instead.
  • Yes: Then see the next question.
• Could you easily fix the problem yourself?
  • Yes: Then just fix it, and don't use the template.
  • No: Then take both of these two steps:
    1. Add the template to the article.
    2. Leave a note on the talk page that describes the neutrality problem.

This isn't very complicated as flowcharts go, but I don't know of any way to draw this on wiki. Does anyone have any ideas for me? WhatamIdoing (talk) 23:29, 8 October 2015 (UTC)

Mediawiki has a number of extensions that allow for creation of flowcharts and diagrams: FlowchartWiki, Dia, and PlantUML, but I don't know if any of these are implemented in Wikipedia's version of mediawiki. --Mark viking (talk) 04:37, 9 October 2015 (UTC)

Use Special:Version to see what extensions are installed. Re the proposal, there is a flowchart at WP:BOLD, revert, discuss cycle#General overview but I don't think it is very helpful—the flowchart was constructed off-wiki then uploaded as an SVG image. The text in the OP is probably as good as it gets. Johnuniq (talk) 05:59, 10 October 2015 (UTC)

Thanks for the replies. None of those extensions are installed here. I would like to avoid creating a static image, but I suppose that it's an option. WhatamIdoing (talk) 17:49, 14 October 2015 (UTC)

Sylvester matrix and User:Akritas2/Modified resultant

Dear mathematicians: Would "Modified resultant" be a useful redirect to the Sylvester matrix article? If so, can someone add a mention of the term in that article? Or is this a valid topic on its own that should be moved to Draft space? It's pretty stale and will soon be deleted under db-g13.—Anne Delong (talk) 11:21, 14 October 2015 (UTC)

I agree to delete the draft. The term "modified resultant" seems WP:OR. As far as I know, it appears literally only in the unique reference of the draft, which is a recent article (2014). Certainly some authors have written things like "we modify the definition of the resultant as follows ...", but "modified resultant" alone has no meaning for the specialists of the resultant. Note also the WP:COI: the author of the draft is one of the authors of the unique cited article. D.Lazard (talk) 13:15, 14 October 2015 (UTC)

Thanks, D.Lazard. If no one edits in during the next week, it should be eligible for db-g13 and I will delete it then.—Anne Delong (talk) 08:20, 16 October 2015 (UTC)

New contributor needs help

A new Wikipedian has repeatedly tried to submit a draft to AFC User:Artyom M. Grigoryan/sandbox/Paired Transform and Fast Fourier Transform but it has been declined repeatedly per WP:NOTJOURNAL - we're at a stalemate. I believe this editor could become a productive contributor but clearly needs help to understand that WP does not simply republish academic articles. BTW his native language appears to Russian, so communicating in that language might help his understanding. Roger (Dodger67) (talk) 11:37, 20 October 2015 (UTC)

Well, a message is send to him. Boris Tsirelson (talk) 18:15, 20 October 2015 (UTC)

Disruption at complex affine space

See WP:DISRUPTSIGNS for context. It is clear disruption to tag an article, and obvious tendentious editing to claim that one editor against four is a "tie". Whoever changed the title of this section obviously can't be bothered to pay attention.

User:TakuyaMurata is disruptively adding a "POV" tag, because he personally appears to disagree with sources like Marcel Berger's "Geometry", Armand Borel's "Linear algebraic groups", Nicolas Bourbaki's "Elements of mathematics", H.S.M. Coxeter's "Introduction to geometry" and "Projective geometry", W.V.D. Hodge and Dan Pedoe's "Methods of algebraic geometry", J S Milne's "Algebraic geometry", and even some of the sources that he himself brought to the discussion. As far as I can tell, any source that does not agree exactly with what appears in Robin Hartshorne's textbook "algebraic geometry" is immediately dubbed "nonstandard" and therefore less relevant to the subject of what a "complex affine space" is (see this revision that is being held up as the epitome of standard).

The kicker is this: Takuya wants to redefine "affine space" to mean the n-fold Cartesian product of a field with itself, equipped with the n coordinate projections, and linear structure. He even went so far as to say that the complex affine n-space carried a canonical Hermitian inner product (and was very insistent for awhile on that point). In other words, for Takuya an "affine space" means the same thing as a coordinate space. It's clear to everyone (except Takuya) that this is a very idiosyncratic view that does not reflect standard terminology. Now, I've bent over backwards to try to accommodate this perspective in the article complex affine space, at least without saying something that is actually wrong. But Takuya insists on restoring the "POV" tag, apparently because he believes that the article should be rewritten from this very weird perspective.

I'm not sure what to do. It's very clear to me that Takuya is simply wrong about the primary use of the term "affine space" in mathematics. But he insists that the primary use should be determined apparently by a single textbook in algebraic geometry that he happens to like. Sławomir
Biały 00:55, 22 October 2015 (UTC)

I am far not expert in algebraic geometry, but anyway, I'd formulate the position of Takuya as follows:

"In algebraic geometry, 'complex affine space' is Cⁿ. (Up to isomorphisms, of course... never mind... all depends on the context.)"

He insists that (some) sources are intentionally vague about "up to what?" and therefore Wikipedia must be equally vague. Boris Tsirelson (talk) 06:51, 22 October 2015 (UTC)

I'm not an expert either; I just wanted to follow the sources and apparently I'm not allowed. Just to be clear; I think the definition depends on a context (say Zariski topology or classical topology). But apparently Wikipedia needs to exist outside the reality ($\mathbb {C} ^{n}$ doesn't have inner product); anyway, I don't understandl this stuff... -- Taku (talk) 07:04, 22 October 2015 (UTC)

No problem with the two topologies; both are invariant under the affine group, thus, both are well-defined on an affine space. There are still other topologies; for example, the fine topology from the potential theory. Still affine invariant. The affine space is, by definition, an algebraic structure (unlike, say, a topological vector space). But the inner product is not affine invariant, of course. When you speak about "embedding of C^m into Cⁿ" (you really did), do you mean the embedding must preserve the inner product, or not? Who knows? The question is: whether the group of automorphisms of an affine space is the affine group (shifts and linear transformations), or rather, depends on the context. Boris Tsirelson (talk) 08:37, 22 October 2015 (UTC)

Sorry, of course, the "affine structure" is unrelated to the topology. Just to be on the record, I'm not debating anything about the definition of an "affine space" as in affine space. When I say "complex affine space", I'm not thinking of any affine space in the sense; I simply meant $\mathbb {C} ^{n}$ and then the topology matters. As for the embedding, again it depends on the context; if we are talking about the embedding of schemes, then it doesn't preserve the inner product since the inner product is not a part of the scheme structure.

All I'm saying that some people (especially algebraic geometers) use the "complex affine space" to mean $\mathbb {C} ^{n}$ (whatever that means). Unfortunate? Perhaps. -- Taku (talk) 08:48, 22 October 2015 (UTC)

A quick Google search turns out many instances (when people are not thinking of any affine structure); e.g., [36]. The key point is that they use "complex affine space" instead of "complex coordinate space". Anyway, I'm tired and I'm not going to press the issue. -- Taku (talk) 09:14, 22 October 2015 (UTC)

Well, if so, this fact could be mentioned in the article (I think so); but as a side remark about an abuse of language, not instead of the "official" definition. Boris Tsirelson (talk) 10:52, 22 October 2015 (UTC)

• "I just wanted to follow the sources": I'm sorry, but this is definitely not what Takuya has been doing. I presented a list of six or seven very standard sources in different areas of geometry and algebra, which Takuya has been doing his best to dismiss. As far as I can tell, there is only one "source" that Takuya has tried to follow, and that is a single textbook in algebraic geometry. In fact, one of the sources that Takuya presented as the new "standard" in algebraic geometry (Vakil's notes), does not support his position at all. (That defines complex affine space as $Spec\mathbb {C} [x_{1},\dots ,x_{n}]$, not $\mathbb {C} ^{n}$.) Yet he persists in arguing that this is literally the same thing as $\mathbb {C} ^{n}$, presumably because of his own confirmation bias.
• In particular, I have directed you to the standard textbook by Hodge and Pedoe, which really should have stopped all argument. They give an extremely clear account of what "affine" means in algebraic geometry, and it is clear how this relates to the standard meaning of the term in "classical" geometry. An affine space is a projective space with a fixed hyperplane "at infinity". In fact, it's really only from this point of view that the adjective "affine" makes sense as it's used nowadays in algebraic geometry. However, apparently instead of bothering to see what they had to say about it, you just wrote off the source as not "contemporary", because you "can't follow their presentations". In fact, I strongly suspect that you haven't even looked to see what they say. Well, you lose the right to claim that you are trying to "follow the sources".
• Regarding the link [37]: I don't see why this is inconsistent with the view in the current article. But we should be clear, $\mathbb {C} ^{n}$ as an affine space is something different from $\mathbb {C} ^{n}$ as a set or $\mathbb {C} ^{n}$ as a topological space, or $\mathbb {C} ^{n}$ as an inner product space. Takuya has systematically failed to appreciate this, despite being asked to clarify his position on multiple occasions.
• "I simply meant $\mathbb {C} ^{n}$ and then the topology matters." Great! But you haven't said what $\mathbb {C} ^{n}$ is. At one point you said that it was a set. At another point you said it was an inner product space. At another point, you agreed that it was an affine space. Now you're saying it's a topological space. All of these are extra things, that are not built into the set $\mathbb {C} ^{n}$. For example, a topology is a collection $\tau$ of subsets satisfying certain axioms. An inner product is a particular kind of complex-valued function. The structure of a vector space is given by a pair of functions, called addition and scalar multiplication, satisfying certain axioms. These are all extra. When someone writes $\mathbb {C} ^{n}$, they may mean some of these things and not others. For example, I have never seen anyone besides you, even in the most egregious language abuse, refer to an inner product on the affine space $\mathbb {C} ^{n}$. By and large, when a geometry refers to the affine space $\mathbb {C} ^{n}$, they mean $\mathbb {C} ^{n}$ with its natural affine structure. (They don't mean it as a linear space, an inner product space, etc.) This is exactly what the article currently does. Yet you insist that there is a POV dispute, but have failed to articulate any clear position.
• In fact, Takuya is the one who is adding the tag, yet admits at Talk:Complex affine space: "But apparently the issue is something else; I don't know what it is myself." Surely, if there is a dispute, the responsibility lies solely with the one adding the tag to clarify what "the issue" is. If there is no issue, there is no reason to add a tag in the first place.
• "Well, if so, this fact could be mentioned in the article": The article already does mention this. Twice. Once in the lead, and once in the section on coordinates. Sławomir
  Biały 11:20, 22 October 2015 (UTC)

My 3cts:

• A complex affine space is an affine space where the underlying vector space is modeled over the complex numbers. An affine space is a triple $(A,V,-)$ where $A$ is a set of points, $V$ is a vector space and $-\colon A\times A\to V$ is a subtraction map which maps two points to the corresponding difference vector (satisfying a few axioms).
• The standard example of a complex affine space is $(\mathbb {C} ^{n},\mathbb {C} ^{n},-)$ where $-$ is the component-wise subtraction of n-tuples. Of course, there are many more examples of such spaces, also infinite-dimensional ones. For example, given a complex vector space $V$, any nonzero linear functional $l\colon V\to \mathbb {C}$ and any complex number $c\in \mathbb {C}$ define a complex affine space $(l^{-1}(c),l^{-1}(0),-)$ with $-$ as vector subtraction.
• That being said, the bulk of the current article Complex affine space is not specific to complex affine spaces but applies to affine spaces over any field (just replace $\mathbb {C}$ by $F$). The article should focus on the special properties of complex affine spaces as defined.

Best wishes, --Quartl (talk) 14:33, 22 October 2015 (UTC)

No objections here. But there is a certain party that seems to believe that a "complex affine space" refers to something that is very different from an affine space that is complex. This party instead believed that a "complex affine space" was defined to be the space of n-tuples of complex numbers, together with n canonically-defined coordinate functions, and a hermitian structure. The reason the current article dwells on affine spaces in general is because this party did not seem to believe that a complex affine space is just an affine space that is complex, and insisted on [this revision as encompassing the "standard" definition of "complex affine space". I'm pretty sure that definition bears very little resemblance to what you've just given (which I would call the standard definition of "complex affine space" as the term would be understood by virtually all practising mathematicians with even a passing familiarity with geometry). Sławomir
Biały 15:36, 22 October 2015 (UTC)

I agree with Biały and others. However there is more to say. From the discussion in Talk:complex affine space, it appears that Taku's concern is about the notion of affine space in algebraic geometry. This discussion appears here because the complexes are an algebraically closed and some people (it seems that Taku is among them) believe wrongly that only algebraic geometry over algebraically closed fields is interesting. Thus the question is "what is an affine space in algebraic geometry?", and this discussion concern also Affine space (algebraic geometry) (an article that has no talk page).

It appears from the whole discussion in Talk:complex affine space that Taku has two theses that are both OR. The first thesis appears explicitly in taku's posts. It is that "affine space" has not the same meaning in algebraic geometry and in usual geometry. IMO this is wrong and the article Affine space (algebraic geometry) should be merged into a section "In algebraic geometry" of Affine space.

The second thesis, less explicit, but rather clear, is that algebraic geometry is scheme theory, and that everything in algebraic geometry must be rewritten in terms of schemes. Corollary: he has edited Affine space (algebraic geometry) for inserting there an OR definition of an affine space in terms of schemes. Unfortunately for him, he forgot that affine spaces have much less automorphisms as affine spaces than as algebraic varieties. This confusion led him to write that every variety that is isomorphic to an affine space is an affine space. In simpler words, a parabola is a line, because they are isomorphic as algebraic varieties! This opinion that algebraic geometry is scheme theory is not only error prone as in this example; it is also the cause that many articles of algebraic geometry are unnecessary too technical. D.Lazard (talk) 21:08, 22 October 2015 (UTC)

Issues with the math notation software

$a\equiv 5{\bmod {3}}\,$

$a\operatorname {giraffe} b\,$

$a\operatorname {giraffe} (b)\,$

$a{\mathbin {??}}b\,$

\operatorname{giraffe} seems to be functioning properly, including a bit of space to the left and right in its first occurrence above and to the left in its second. I seem to recall the spacing was formerly not working correctly.

However, the first line above uses \bmod, which should behave like a binary operation symbol. These behave as follows:

$3+5\,$

$+5\,$

The point is there is some space to the left and right when "+" is used as a binary operator and no such space to the right when it's used as a unary operator as in "+5". \bmod doesn't seem to have proper spacing.

The line with the two question marks is coded as follows:

a \mathbin{??} b \,

Since \mathbin is supposed to make something behave like a binary operation symbol, there should be spacing, as in 3 + 5. That's not working.

Who attends to bugs in this kind of thing? Would such a person be reading this page? Or should I go straight to bugzilla? Michael Hardy (talk) 19:14, 25 October 2015 (UTC)

Probably straight to https://phabricator.wikimedia.org/ — I don't think the devs normally follow this page. But there appears to be more than one bug here. Your bmod example has no spacing around the mod in the default "PNG images" rendering mode for math, but looks ok when I change to "MathML with SVG or PNG fallback" (which I think uses the SVG fallback for me since I'm using Chrome). Your ?? example has no spacing around the ?? for both rendering modes. I verified that the actual LaTeX rendering of this example does put spaces around it. Incidentally, there is something wrong with \mathrel, too.

a+b — $a+b$

a\mathbin{+}b — $a{\mathbin {+}}b$

a\mathrel{+}b — $a{\mathrel {+}}b$

In LaTeX, these three look almost the same, but the mathrel one has very subtly wider spacing. Here (with the SVG fallback view) the ones with the explicit mathbin and mathrel have no spacing. —David Eppstein (talk) 19:46, 25 October 2015 (UTC)

Are we collecting misbehaviors of the WP math rendering system anywhere? Because here's another one. The input

\frac{1}{4} \left\lfloor\frac{n}{2}\right\rfloor\left\lfloor\frac{n-1}{2}\right\rfloor\left\lfloor\frac{n-2}{2}\right\rfloor\left\lfloor\frac{n-3}{2}\right\rfloor,

produces

${\frac {1}{4}}\left\lfloor {\frac {n}{2}}\right\rfloor \left\lfloor {\frac {n-1}{2}}\right\rfloor \left\lfloor {\frac {n-2}{2}}\right\rfloor \left\lfloor {\frac {n-3}{2}}\right\rfloor ,$

in which (in my viewing, using SVG fallback in Chrome) the first fraction's floor brackets are much smaller than the other ones. They are all the same size in LaTeX, or in the default bitmap view, or for that matter on other sites that use MathJax for their rendering. The workaround in this case is to use explicit sizing \biggl and \biggr instead of \left and \right. —David Eppstein (talk) 05:30, 26 October 2015 (UTC)

suggested move gradian -> gon (angle)

I submitted an page move request for renaming gradian to Gon (angle) or Gon (angle measurement)), gon is the ISO unit (ISO 80000-3#Units of angle. Join the discussion at Talk:Gradian#Requested move 27 October 2015. I don't really care anyway, but it is a bit do we adhere to ISO standards. WillemienH (talk) 08:36, 27 October 2015 (UTC)

Comment on Draft:Geometric set

Your comments on Draft:Geometric set are welcomed. Please use Preferences → Gadgets → Yet Another AFC Helper Script, or use {{afc comment|your comment here}} directly in the draft. -- Sam Sailor ^Talk! 11:12, 27 October 2015 (UTC)

Binomial

Please, look at, and comment the requested move at Talk:Binomial (polynomial)‎‎#Requested move 27 October 2015 — D.Lazard (talk) 14:42, 27 October 2015 (UTC)

Depressing a polynomial article

Do people think that there is enough information available and/or enough notability(?) to have an article on Depressing a polynomial?— Preceding unsigned comment added by ‎Naraht (talk • contribs)

As "depressing a polynomial" is commonly called Tschirnhaus transformation (although there are other Tschirnhaus transformations), it would be better to expand Tschirnhaus transformation to include this and to create only a redirect. D.Lazard (talk) 20:05, 27 October 2015 (UTC)

I add my vote that this is an article worth expanding. It is not very useful in its present form. Sławomir
Biały 23:34, 27 October 2015 (UTC)

Also, I note the mathematical definition in Wiktionary is incorrect...Naraht (talk) 02:11, 28 October 2015 (UTC)

Created new article - British statistician Roger Thatcher

I've created a new article on the British statistician Roger Thatcher.

Additional input for further research collaboration and secondary sources would be appreciated at the article's talk page, at Talk:Roger Thatcher.

Thank you,

— Cirt (talk) 05:12, 30 October 2015 (UTC)

Comment on draft at User:Mjirina/sandbox

Your comments on User:Mjirina/sandbox are welcomed. Please use Preferences → Gadgets → Yet Another AFC Helper Script, or use {{afc comment|your comment here}} directly in the draft. -- Sam Sailor ^Talk! 09:10, 29 October 2015 (UTC)

Tagged for speedy deletion as a copyright violation. —David Eppstein (talk) 05:49, 30 October 2015 (UTC)

problem with the math-rating template ?

I noticed that when in the math rating template Template:Maths rating I follow the link generated by the field=basic part I get forwarded to the (almost) empty page Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Basics cI am not sure where to link it to Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Fields or Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Fields#basic seem good candidates , or maybe we could add more content to Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Basics any ideas on this? (lets first discuss this before we get edit wars about it, although I would not even know how to edit this complicated template) WillemienH (talk) 12:30, 31 October 2015 (UTC)

A link to Category:Mathematics articles related to basic mathematics might be useful.--Salix alba (talk): 14:37, 31 October 2015 (UTC)

Nov 2015

Wikipedia talk:WikiProject Mathematics/Archive/2015/Nov

Dec 2015

Wikipedia talk:WikiProject Mathematics/Archive/2015/Dec