Graphics, Figures & Tables ⇒ Stereographic map projections for drawing ellipsoids

[matsun]

I would need to plot with Tikz some 3D drawings of ellipsoids: I am trying to adapt the excellent code provided by Tomas M. Trzeciak for plotting spheres based on stereographic and cylindrical map projections.

Original code: http://www.texample.net/tikz/examples/map-projections/

I started to have a look at the functions but I do not know Tex very well.. Is there anyone skilled in math and Tex who's willing to help me?

I started to check the command \LongitudePlane:

Code: Select all

\newcommand\LongitudePlane[3][current plane]{%
  \pgfmathsinandcos\sinEl\cosEl{#2} % elevation
  \pgfmathsinandcos\sint\cost{#3} % azimuth
  \tikzset{#1/.estyle={cm={\cost,\sint*\sinEl,0,\cosEl,(0,0)}}}
}

but I am already lost.. What does [current plane] stand for? What is the output of this function?

Thank you for the support!

[Stefan Kottwitz]

Hi matsun,

welcome to the forum!

current plane is an parameter of this function. This function/macro is called several times with various planes, that are: xzplane, pzplane, qzplane, and equator.

cm may stand for "coordinate matrix", just a quick guess, as I could not look deeper into the code yet.

Stefan