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OldPolyhedra :: commonFace

commonFace -- checks if the intersection is a face of both Cones or Polyhedra, or of cones with fans



commonFace checks if the intersection of C1 and C2 or the intersection of P1 and P2 is a face of both. If it is applied to a pair of a cone C and a fan F then it checks if the intersection of C with every generating cone of F is a face of each. For two fans it checks this condition for every pair of generating cones. If applied to a list then the list must contain Fans and Cones and it checks pairwise for a common face.

For example, consider the following three cones:

i1 : C1 = posHull matrix {{1,0},{0,1}};
i2 : C2 = posHull matrix {{1,-1},{0,-1}};
i3 : C3 = posHull matrix {{1,-1},{2,-1}};

for each pair of two of them we can check if their intersection is a common face:

i4 : commonFace(C1,C2)

o4 = true
i5 : commonFace(C2,C3)

o5 = true
i6 : commonFace(C3,C1)

o6 = false

Ways to use commonFace :

For the programmer

The object commonFace is a method function.