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Polyhedra :: faceFan

faceFan -- computes the fan generated by the cones over the faces

Synopsis

Description

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 hte 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

Ways to use faceFan :