#include "petscdt.h" PetscErrorCode PetscDTBaryToIndex(PetscInt len, PetscInt sum, const PetscInt coord[], PetscInt *index)
| len | - the desired length of the barycentric tuple (usually 1 more than the dimension it represents, so a barycentric coordinate in a triangle has length 3) | |
| sum | - the value that the sum of the barycentric coordinates (which will be non-negative integers) should sum to | |
| coord | - a barycentric coordinate with the given length and sum |
| index | - the unique index for the coordinate, >= 0 and < Binomial(len - 1 + sum, sum) |
Note: the indices map to barycentric coordinates in lexicographic order, where the first index is the least significant and the last index is the most significant.