#include "petscmat.h" PetscErrorCode MatMFFDSetPeriod(Mat mat,PetscInt period)Logically Collective on Mat
| mat | - the matrix free matrix created via MatCreateSNESMF() | |
| period | - 1 for every time, 2 for every second etc |
| -mat_mffd_period <period> | - Sets how often h is recomputed |