#include "petscpc.h" PetscErrorCode PCHYPRESetDiscreteGradient(PC pc, Mat G)Collective on PC
| pc | - the preconditioning context | |
| G | - the discrete gradient |
Notes: G should have as many rows as the number of edges and as many columns as the number of vertices in the mesh Each row of G has 2 nonzeros, with column indexes being the global indexes of edge's endpoints: matrix entries are +1 and -1 depending on edge orientation