Calculate vertices of isoquant triangles in a 3-D distributed array. This takes a PETSc DA object, does some sanity checks, calculates array sizes, and then gets the local part of the array and passes it to Draw3DBlock for triangulation.
int DATriangulate ( DA theda, Vec X, int this, PetscScalar* minmax, int n_quants, PetscScalar* isoquants, PetscScalar* colors )