PCMGSetRestriction

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

#include "petscksp.h" 
#include "petscmg.h"   
PetscErrorCode PETSCKSP_DLLEXPORT PCMGSetRestriction(PC pc,PetscInt l,Mat mat)

Collective on PC and Mat

	pc	- the multigrid context
	mat	- the restriction matrix
	l	- the level (0 is coarsest) to supply

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 PCMGSetInterpolate() is used.

MG, set, multigrid, restriction, level