ASKSAGE: Sage Q&A Forum - RSS feedhttps://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Thu, 06 Jun 2013 17:13:30 +0200Error intersecting polyhedrahttps://ask.sagemath.org/question/10202/error-intersecting-polyhedra/I have a dictionary of polyhedra which I want to consider various intersections and unions of. For now, my dictionary has four polyhedra in it. When running the following for loop:
v={} # contains coordinates of the tetrahedron, centered at (0,0,0)
v[1] = vector([1,0,-1/sqrt(2)])
v[2] = vector([-1,0,-1/sqrt(2)])
v[3] = vector([0,1,1/sqrt(2)])
v[4] = vector([0,-1,1/sqrt(2)])
V = {1,2,3,4}
b={} # will contain coordinates of vertices of the subdivision of the tetrahedron
for X in powerset(V):
q = len(X)
if q > 0:
b[tuple(X)] = (1/q)*sum([v[i] for i in X])
poly_int = Polyhedron([b[key] for key in b.keys()]) # this is a tetrahedron containing
# all of my polyhedra
for i in [1,2,3,4]:
poly_int = poly[i] & poly_int
I get a very nasty error:
AttributeError: 'Polyhedra_RDF_cdd_with_category.element_class'
object has no attribute '_Vrepresentation'
(The traceback for the error is quite long. I can include it if needed.)
Manually computing
poly[1] & poly[2] & poly[3] & poly[4]
gives the same error. HOWEVER, if instead I compute
(poly[1] & poly[2]) & (poly[3] & poly[4])
I get no errors. While this is a fine workaround for this particular case, I'm scripting these intersections and need some way to actually compute these intersections automatically. Using something like
poly[1].intersection(poly[2]) # etc.
doesn't help either. Any thoughts?BillThu, 06 Jun 2013 17:13:30 +0200https://ask.sagemath.org/question/10202/