Talk:Lambert cylindrical equal-area projection

Formula for X is wrong

This is a great series of articles on projections, and I especially like the maps by Mdf! However, the formula for X is wrong in this article, except in the standard equatorial case. Per the Snyder reference, p. 77, X should be multiplied by $cos\phi _{0}$ in addition to dividing Y by the same factor, where $\phi _{0}$ is the reference latitude at which vertical and horizontal scale are to be equal and there is to be no shape distortion. The aspect ratio is then $\pi (cos\phi _{0})^{2}$: 1.

I'll try to change the formula in the article.HuMcCulloch (talk) 03:33, 16 February 2008 (UTC)

I'm looking at the Snyder reference, p. 77 and 78 right now.

While everything you have said is true for the general case of the cylindrical equal-area projection, Snyder indicates that the "Lambert cylindrical equal-area projection" is, in fact, the special case you mentioned -- equatorial.

Should we move the general equation to the "cylindrical equal-area projection" article, and revert this "Lambert cylindrical equal-area projection" article back to the special case formula? --68.0.124.33 (talk) 22:43, 15 July 2010 (UTC)

Yes, done that. Somebody should look at the cylindrical equal-area projection article. It's not in a good shape... Uwe Dedering (talk) 22:04, 13 August 2010 (UTC)

Replace low-contrast images

I will be replacing images on the various map projection pages. Presently many are on a satellite composite image from NASA that, while realistic, poorly demonstrates the projections because of dark color and low contrast. I have created a stylization of the same data with much brighter water areas and a light graticule to contrast. See the thumbnail of the example from another article. Some images on some pages are acceptable but differ stylistically from most articles; I will replace these also.

The images will be high resolution and antialiased, with 15° graticules for world projections, red, translucent equator, red tropics, and blue polar circles.

Please discuss agreement or objections over here (not this page). I intend to start these replacements on 13 August. Thank you. Strebe (talk) 22:42, 6 August 2011 (UTC)

BBC

This reminds me of the projection used in bbc broadcasts in the 60s/70s.(mercurywoodrose)75.61.135.200 (talk) 04:44, 16 November 2011 (UTC)

Proper Description of Distortion

Strebe, the sentence you added about the poles is generic to all Cartesian (is that the right word?) projections of a globe, and should be in cylindrical equal-area projection. This article should specify that Lambert is more distorted (away from the equator) than its siblings. - Frankie1969 (talk) 14:55, 15 February 2012 (UTC)

Done. Strebe (talk) 21:10, 15 February 2012 (UTC)

Relationship between sphere and cylinder

This statement is clearly incorrect, as explained in the linked Wikipedia article: "In the work On the Sphere and Cylinder, Archimedes shows that a sphere has the same area as a cylinder around it..." In fact, the cylinder has much larger area. The reference to Archimedes work should be corrected and related to the projection, or simply removed. brian|bp 03:17, 20 November 2016 (UTC) — Preceding unsigned comment added by Brian abp (talk • contribs)

The calculation is correct. Strebe (talk) 04:57, 20 November 2016 (UTC)

The calculation is correct but the text was nonsense. Overall area being the same is no demonstration of the equal-area property. I went ahead and deleted the sentence. Strebe (talk) 17:04, 30 November 2016 (UTC)

File:Lambert cylindrical equal-area projection SW.jpg to appear as POTD soon

Hello! This is a note to let the editors of this article know that File:Lambert cylindrical equal-area projection SW.jpg will be appearing as picture of the day on December 18, 2016. You can view and edit the POTD blurb at Template:POTD/2016-12-18. If this article needs any attention or maintenance, it would be preferable if that could be done before its appearance on the Main Page. — Chris Woodrich (talk) 01:54, 30 November 2016 (UTC)

Picture of the day

The Lambert cylindrical equal-area projection is a cylindrical equal-area projection used in cartography. Attributed to the Swiss mathematician Johann Heinrich Lambert, this projection is undistorted along the equator, which is its standard parallel. Distortion increases rapidly, however, towards the poles, which become lines instead of points.Map: Strebe, using Geocart

Done, Chris Woodrich, with a couple of corrections. Thanks for your tireless work! Strebe (talk) 17:09, 30 November 2016 (UTC)

Proposal: merge to cylindrical equal-area projection

I think readers of this article would benefit from the context provided at cylindrical equal-area projection (and more context which could be provided if that article were further expanded), but independently from that subject, it doesn’t seem to me like there’s enough specific material here to warrant a separate article. Thus I am proposing merging this and a few similar stubs into that article. See the discussion I started there. –jacobolus (t) 21:49, 10 January 2023 (UTC)

Agreed. Strebe (talk) 22:06, 10 January 2023 (UTC)

:Oppose.

1. Target "cylindrical equal-area projection" is too broad.
2. Merging by size isn't consistent with other map projection articles.
3. Leaving one projection out increases inconsistency further - one is too big to be integrated, on the other hand the target is much broader than the combination of the pages proposed to be merged.
4. "readers of this article" could also benefit from the "the context provided at cylindrical equal-area projection" be providing a link to that page - and even more, by linking to a page that has a topic restricted to what the pages proposed to be merged are about.

Euro2023 (talk) 00:01, 11 January 2023 (UTC) CU blocked

Please direct discussion to talk:cylindrical equal-area projection#Proposal: merge specific cylindrical equal-area projection pages into this page. –jacobolus (t) 00:12, 11 January 2023 (UTC)