Talk:Peirce quincuncial projection

message: It would be great to have a better image that shows meridians and main parallels. It will make it clearer how the Equator maps to a square.Dmgerman 17:13, 4 July 2007 (UTC)
thread_title: Image

message: In this edit it was asserted that this projection is not based in any meaningful way on the stereographic projection.  I would agree that the unqualified and unexplained assertion that it's "based on the stereographic projection" is not very informative and probably incomprehensible to anyone who hasn't thought about the math.
: 
However: Jacobi's elliptic functions take the torus to the plane, and then the (inverse of the) stereographic projection takes the plane to the Riemann sphere.  Hence the correspondence between the torus and the sphere is a composition of the two.  You'll see this discussed if you read some of the referenced math articles. Michael Hardy (talk) 20:51, 24 October 2010 (UTC)
replies: text: That’s true, but not important. I could say the same thing about the ellipsoidal transverse Mercator. Really, any conformal projection can be shuffled through the stereographic before reaching its “destination”, since the stereographic is a convenient way of transforming the sphere to the plane. From there what happens is nothing but function composition. But the stereographic is not necessary; other functions will do. Any conformal transformation to the plane will do. Strebe (talk) 03:50, 25 October 2010 (UTC)
replies: text:   You say other functions will do, but then the next function with which it would be composed would not be the inverse of the standard Jacobi elliptic function. Michael Hardy (talk) 01:46, 23 December 2016 (UTC)
replies: text: Of course that is true. What is the significance? Strebe (talk) 21:16, 24 December 2016 (UTC)
thread_title:  Stereographic? 

message: 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) 22:46, 6 August 2011 (UTC)
thread_title: Replace low-contrast images

message: For the illustration, I think it would be better to choose a prime meridian that avoids Africa.  That is the way it's presented here: http://www.quadibloc.com/maps/mcf0703.htm
I have no political agenda, I just think it looks bad right now!  Alright, so I have an aesthetic agenda. Kyle Cronan (talk) 03:55, 20 March 2012 (UTC)
replies: text: Done. Strebe (talk) 04:03, 23 July 2012 (UTC)
replies: text: Awesome, love it! Kyle Cronan (talk) 00:09, 7 August 2012 (UTC)
thread_title:  Meridian 

message: Hello! This is a note to let the editors of this article know that :File:Peirce quincuncial projection SW 20W.JPG will be appearing as picture of the day on April 14, 2016. You can view and edit the POTD blurb at Template:POTD/2016-04-14. 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) 23:41, 27 March 2016 (UTC)
replies: text: Hello Chris Woodrich, and thanks for your tireless efforts! I pared back mention of Schwarz-Christoffel transformation from the image description under the theory that only mathematicians would benefit from that part of the blurb. If anyone thinks otherwise, let's talk. Thanks. Strebe (talk) 17:59, 28 March 2016 (UTC)

text: *Alright.  — Chris Woodrich (talk) 00:29, 29 March 2016 (UTC)
thread_title:  [[:File:Peirce quincuncial projection SW 20W.JPG]] to appear as POTD soon