Hello,
I'd have some questions and suggestions about the functions in
polyhedra.py. I attached a patch with some very simple doc and error
handling improvements. Please tell me if it sound useful. (the patch
is against sage 3.2.1, if you prefer me to use a more current version
of polyhedra, please tell).
I was also wondering in which circumstances is the Polyhedron.union()
method [1] useful ? For polytopes ? By the way this method name is
IMHO misleading, I would have expected it to return the union of the
polyhedra (which may not be a polyhedron).
I also do not fully understand how cdd is called (and packaged). Is it
a separated process ? If so, is there a particular reason for not
wrapping cddlib instead ?
Last question: do you consider a Polyhedron defined with rays and no
vertex as valid from a theoretical point of view ? For instance
p = Polyhedron(rays = [[0,1],[1,0]]) is invalid
p = Polyhedron(vertices=[[0,0]], rays = [[0,1],[1,0]]) is valid
p = Polyhedron(vertices=[[0,0]], rays = [[0,1],[0,-1],[1,0],[-1,0]]) is valid
p = Polyhedron(rays = [[0,1],[0,-1],[1,0],[-1,0]]) is ????
If the last is invalid too, some sanity checks can be easily added to
the __init__() method.
[1]
def union(self, other):
"""
Returns a polyhedron whose vertices are the union of the vertices
of the two polyhedra.
....
--
Best regards
bastien Barthélemy
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to sage-devel@googlegroups.com
To unsubscribe from this group, send email to
sage-devel-unsubscr...@googlegroups.com
For more options, visit this group at http://groups.google.com/group/sage-devel
URLs: http://www.sagemath.org
-~----------~----~----~----~------~----~------~--~---
