petsc-3.7.7 2017-09-25

PCMGGetSmoother

Gets the KSP context to be used as smoother for both pre- and post-smoothing. Call both PCMGGetSmootherUp() and PCMGGetSmootherDown() to use different functions for pre- and post-smoothing.

Synopsis

#include "petscksp.h" 
PetscErrorCode  PCMGGetSmoother(PC pc,PetscInt l,KSP *ksp)

Not Collective, KSP returned is parallel if PC is

Input Parameters

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

Ouput Parameters

ksp -the smoother

Notes

Once you have called this routine, you can call KSPSetOperators(ksp,...) on the resulting ksp to provide the operators for the smoother for this level. You can also modify smoother options by calling the various KSPSetXXX() options on this ksp. In addition you can call KSPGetPC(ksp,&pc) and modify PC options for the smoother; for example PCSetType(pc,PCSOR); to use SOR smoothing.

Keywords

MG, get, multigrid, level, smoother, pre-smoother, post-smoother

Examples

src/snes/examples/tutorials/ex12.c.html