isFine -- test whether a triangulation uses every point in the configuration

• Usage:

  isFine T

  isFine(A, tri)

• Inputs:
  • T, an instance of the type Triangulation,
  • A, a matrix, whose columns are the points of a configuration
  • tri, a list, a triangulation of the columns of $A$
• Outputs:
  • a Boolean value, whether every column index appears in some maximal simplex of the triangulation

i1 : A = transpose matrix {{0,3},{0,1},{-1,-1},{1,-1},{-4,-2},{4,-2}}

o1 = | 0 0 -1 1  -4 4  |
     | 3 1 -1 -1 -2 -2 |

              2       6
o1 : Matrix ZZ  <-- ZZ

i2 : Ts = allTriangulations A;

i3 : tally apply(Ts, isFine)

o3 = Tally{false => 10}
           true => 6

o3 : Tally