Sets the function to be used to restrict dual vectors from level l to l-1.


#include "petscksp.h" 
PetscErrorCode  PCMGSetRestriction(PC pc,PetscInt l,Mat mat)
Logically Collective on PC

Input Parameters

pc - the multigrid context
l - the level (0 is coarsest) to supply [Do not supply 0]
mat - the restriction matrix

Level: advanced


Usually this is the same matrix used also to set the interpolation for the same level.

One can pass in the interpolation matrix or its transpose; PETSc figures out from the matrix size which one it is.

If you do not set this, the transpose of the Mat set with PCMGSetInterpolation() is used.

See Also