Re: [Gnuplot-info] Spherical geometry diagrams - is gnuplot the right tool?

[Hans-Bernhard B. <br...@ph...>]

Geo...@bl... wrote:

> 1) A sphere tangent to a plane at its south pole.  Meridians drawn with
> hidden line removal.  Two lines, drawn in a different style, between the
> north pole and the plene, passing through the sphere without
> hidden-line removal.

Start with 'demo/world.dem', add some 'set arrow ... nohead' statements 
for the rays.

> 2) The upper, "north" half of a sphere, with the angle between two
> parallels indicated with an arrow and labeled, and the angle between two
> meridians indicated with an arrow and labeled.

Similar to above.

> 3) Upper half of a sphere, an oblique tangent plane to the sphere (hiding
> part of the sphere), and a cartesian coordinate system sketched and labeled
> on the plane

Draw both the half-sphere and the plane in parametric mode, with 
hidden3d on.