petsc-3.8.4 2018-03-24
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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.

Keywords

MG, set, multigrid, restriction, level

See Also

PCMGSetInterpolation(), PCMGGetRestriction()

Level:advanced
Location:
src/ksp/pc/impls/mg/mgfunc.c
Index of all PCMG routines
Table of Contents for all manual pages
Index of all manual pages

Examples

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