For a polyhedron with the origin in its relative interior, the face fan is the fan generated by the cones over the faces of the polytope. Hence the origin must be in the relative interior.
i1 : P = hypercube 2 o1 = P o1 : Polyhedron |
i2 : F = faceFan P o2 = F o2 : Fan |
i3 : raysF = rays F o3 = | -1 1 -1 1 | | -1 -1 1 1 | 2 4 o3 : Matrix ZZ <--- ZZ |
i4 : apply(maxCones F, mc -> raysF_mc) o4 = {| -1 -1 |, | 1 1 |, | -1 1 |, | -1 1 |} | -1 1 | | -1 1 | | -1 -1 | | 1 1 | o4 : List |
The object faceFan is a method function.