petsc-3.12.5 2020-03-29
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