tailCone -- computes the tail/recession cone of a polyhedron

Usage:

C = tailCone P
Inputs:
- P, a convex polyhedron
Outputs:
- C, a convex rational cone

Description

Every polyhedron P can be uniquely decomposed into the sum of a polytope and a cone, the tail or recession cone of P. Thus, it is the cone generated by the non-compact part, i.e. the rays and the lineality space of P. If P is a polytope then the tail cone is the origin in the ambient space of P.

i1 : P = polyhedronFromHData(matrix{{-1,0},{1,0},{0,-1},{-1,-1},{1,-1}},matrix{{2},{2},{-1},{0},{0}}) 

o1 = P

o1 : Polyhedron

i2 : C = tailCone P

o2 = C

o2 : Cone

i3 : rays C

o3 = | 0 |
     | 1 |

              2       1
o3 : Matrix ZZ  <-- ZZ

Ways to use tailCone:

tailCone(Polyhedron)

For the programmer

The object tailCone is a method function.

The source of this document is in Polyhedra/documentation/old_documentation.m2:2199:0.