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Documentation to "Functions for plotting polyhedra". more details wanted #31405

Open 50e11902-eb93-4bd9-9430-4325b5a3ab56 opened 3 years ago

50e11902-eb93-4bd9-9430-4325b5a3ab56 commented 3 years ago

doc/sage/html/en/reference/discrete_geometry/sage/geometry/polyhedron/plot.html

1) Apparently, schlegel_projection works only for 4d to 3d. Or also for 3d to 2d? (That would be nice to have.) 5d to 4d? Please mention

2) There is no such thing as a "stereographic projection" of a polytope. Stereographic projection is a mapping between a sphere and a hyperplane. What this really is is just a central projection, from some point. (like the Schlegel diagram as well, except that the projection center is constrained). Where is the image hyperplane? Probably perpendicular to the vector from 0 to the projection center? Can that point be 0? Does the projection plane go through the origin, or does it touch the unit ball? What happens if the point lies inside the unit ball?

3) Is there no parallel projection? (or special case orthogonal projection) Or is it in some other module?

CC: @jplab @kliem @LaisRast

Component: documentation

Keywords: Schlegel diagram, polytope

Issue created by migration from https://trac.sagemath.org/ticket/31405

jplab commented 3 years ago

Changed author from Günter Rote to none

jplab commented 3 years ago

Changed keywords from Schlegel diagram to Schlegel diagram, polytope

jplab commented 3 years ago
comment:3

Ok, will address these questions ASAP.

mkoeppe commented 3 years ago
comment:4

Sage development has entered the release candidate phase for 9.3. Setting a new milestone for this ticket based on a cursory review of ticket status, priority, and last modification date.