Welcome!

Hello Guido Kanschat, and welcome to Wikipedia! Thank you for your contributions. I hope you like the place and decide to stay. Here are a few good links for newcomers:

I hope you enjoy editing here and being a Wikipedian! Please sign your name on talk pages using four tildes (~~~~); this will automatically produce your name and the date. If you have any questions, check out Wikipedia:Where to ask a question or ask me on my talk page. Again, welcome! --Shanel 23:51, 3 November 2005 (UTC)Reply

FEM

edit

Dear Guido. I agree that the article on the finite element method is in a very bad state and I would be extremely glad if you could rewrite it. It's not an easy job, but you know obviously enough about it (I had a brief look at your cv). You might want to read something about the conventions here; Wikipedia:WikiProject Mathematics and Wikipedia:Manual of Style (mathematics) are good starting points specific to maths. The thing to keep in mind is to make an effort to connect to non-experts. For instance, from your contribution to Galerkin method, it is not clear that this is in fact often used for PDEs because you work in an abstract Hilbert space; I hope you intend to expand the article and make the connection to applications. I put some specific remarks on Talk:Finite element method.

I hope to see more of your contributions. Tschüss, Jitse Niesen (talk) 15:15, 9 December 2005 (UTC)Reply

Galerkin method

edit

As requested, some comments on Galerkin method. Firstly, on the mathematics. I noticed some things that should perhaps be changed. However, it's up to you in first instance; if you disagree, leave it as it is.

  • I'm amused that you say that FEM is an example of Galerkin, while I read a book last week which implies that Galerkin was a specific finite element method. Well, I guess "finite element method" is not uniquely defined.
  • Mention that   should be finite-dimensional to get a matrix equation.
  • The u in the Galerkin orthogonality relation is not just any odd u, but the solution of the equation.
  • I never realized that conjugate gradient can be considered as a Galerkin method; that's pretty neat.
  • The notation in   is slightly inconsistent, as there is a different   on the left- and right-hand side.
  • The result that the matrix is symmetric if and only if the bilinear form is symmetric, is only true if you mean "the bilinear form is symmetric on  ". By the way, you introduce symmetry for bilinear forms just below this result, which is the wrong way around, I guess.

Then, some remarks on style

  • It is considered bad style to put links in section headings.
  • Please include some references. Things you might include are: original papers (is there a paper by Galerkin in which the method is developed?) and sources that you consulted while writing the article (this is just academic honesty). Most important in my view is to give some pointers to readers who either want to learn more (for instance, the proof of Cea's theorem) or that do not quite understand the article and want to read an alternative treatment somewhere else.

Finally, the technical support for mathematics in Wikipedia is not perfect. You might notice that equations are sometimes presented as text (HTML) and sometimes as pictures (PNG). For instance, in the first section, you wrote

"Let us introduce Galerkin's method with an abstract problem posed as a weak formulation on a Hilbert space  , namely, find   such that for all  
 
holds. Here,   is a bilinear form and   is a linear form on  ."
Let us introduce Galerkin's method with an abstract problem posed as a [[weak formulation]] on a [[Hilbert space]] <math>V</math>, namely, find <math>u\in V</math> such that for all <math>v\in V</math>
:<math>a(u,v) = f(v)</math>
holds. Here, <math>a(.,.)</math> is a [[bilinear form]] and <math>f</math> is a [[linear form]] on <math>V</math>.

The expression   is in picture format, and the expression   is in text format. In most browsers, the layout is the best if you make sure that the mathematical expression in the running text ($...$ in LaTeX) are in text format, and those in displayed equations ($$...$$ in LaTeX) in picture format.

"Let us introduce Galerkin's method with an abstract problem posed as a weak formulation on a Hilbert space V, namely, find uV such that for all vV
 
holds. Here, a(.,.) is a bilinear form and f is a linear form on V."
Let us introduce Galerkin's method with an abstract problem posed as a [[weak formulation]] on a [[Hilbert space]] ''V'', namely, find ''u'' ∈ ''V'' such that for all ''v'' ∈ ''V''
:<math>a(u,v) = f(v) \,</math>
holds. Here, ''a''(.,.) is a [[bilinear form]] and ''f'' is a [[linear form]] on ''V''.

It's up to you whether you care about this; many don't.

I apologize for the length; I've written more than I'd intended to. In fact, the article is very good, especially for somebody who is quite new here, and I don't expect you to follow all my suggestions. But please do put in some references; this is a pet peeve of me (don't care about the format of the references). Cheers, Jitse Niesen (talk) 02:25, 10 December 2005 (UTC)Reply

Hi

edit

Hi Guido. I would like to thank you for the work and new articles you contributed to Wikipedia. And by the way, if at some point you feel like writing more new articles and are looking for a topic, I have a request. :) An article on the Bramble-Hilbert lemma would be nice to have, as I think it is an important topic, and I think that you may be familiar with it, being a finite element person. But that's just a random suggestion. :) Cheers, Oleg Alexandrov (talk) 00:33, 24 April 2006 (UTC)Reply

Opinion sought

edit

Hello. You made a change to The Good Person of Sezuan page recently - removing the suggestion that it was voluntary exile when he left after the Reichstag fire. I'd be grateful if you could offer your opinion on the navigation template at the end of the page - I've made it non-collapsing, but an opera person is objecting. When you get a moment, please take a look. Many thanks, DP —Preceding unsigned comment added by 90.199.166.2 (talk) 12:04, 17 September 2007 (UTC)Reply