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# vertexEdgeMatrix -- computes the vertex-edge-relations matrix

- Usage:
    `M = vertexEdgeMatrix P`
- Inputs:
  - P, a convex polyhedron
- Outputs:
  - M, a matrix

## Description

vertexEdgeMatrix computes the matrix M where the columns are indexed by the edges and the rows are indexed by the vertices of P and has 1 as an entry if the corresponding edge contains this vertex and 0 otherwise.

    i1 : P = cyclicPolytope(3,5)

    o1 = P

    o1 : Polyhedron

    i2 : vertexEdgeMatrix P

    o2 = | 0 1 2 3 4 5 6 7 8 9 |
         | 1 1 0 1 1 0 0 1 0 0 |
         | 2 0 1 1 0 0 0 0 0 1 |
         | 3 1 1 0 0 1 0 0 1 0 |
         | 4 0 0 0 1 1 1 0 0 0 |
         | 5 0 0 0 0 0 1 1 1 1 |

                  6       10
    o2 : Matrix ZZ  <-- ZZ

## Ways to use vertexEdgeMatrix:

- `vertexEdgeMatrix(Polyhedron)`

## For the programmer

The object vertexEdgeMatrix is a method function.

The source of this document is in /build/macaulay2-88fgJW/macaulay2-1.25.11+ds/M2/Macaulay2/packages/Polyhedra/documentation/old_documentation.m2:2266:0.