petsc-3.11.2 2019-05-18
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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.

Keywords

MG, set, multigrid, restriction, level

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