petsc-master 2019-12-13
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PCMGGetRScale

Gets the pointwise scaling for the restriction operator from level l to l-1.

Synopsis

#include "petscksp.h" 
PetscErrorCode PCMGGetRScale(PC pc,PetscInt l,Vec *rscale)
Collective on PC

Input Parameters

pc - the multigrid context
rscale - the scaling
l - the level (0 is coarsest) to supply [Do not supply 0]

Notes

When evaluating a function on a coarse level one does not want to do F(R * x) one does F(rscale * R * x) where rscale is 1 over the row sums of R. It is preferable to use PCMGGetInjection() to control moving primal vectors.

See Also

PCMGSetInterpolation(), PCMGGetRestriction(), PCMGGetInjection()

Level

advanced

Location

src/ksp/pc/impls/mg/mgfunc.c

Examples

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

Index of all PC routines
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Index of all manual pages