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Polyhedra :: facets

facets -- Giving the facet inequalities of a cone or polyhedron.

Synopsis

Usage:

fC = facets C

fP = facets P
Inputs:
- C, a convex rational cone
- P, a convex polyhedron
Outputs:
- M, a matrix
- L, a list

Description

For a cone one matrix is returned.

For a polyhedron the affine inequalities are returned as a pair of two matrices, where the second matrix consists of a single row.

Please see V- and H-representation on the conventions we use for cones and polyhedra.

i1 : fC = facets posOrthant 2

o1 = | 1 0 |
     | 0 1 |

              2        2
o1 : Matrix ZZ  <--- ZZ

i2 : fP = facets hypercube 2

o2 = (| -1 0  |, | 1 |)
      | 1  0  |  | 1 |
      | 0  -1 |  | 1 |
      | 0  1  |  | 1 |

o2 : Sequence

Ways to use `facets` :

"facets(Cone)"
"facets(Polyhedron)"

For the programmer

The object facets is a method function.