petsc-3.9.4 2018-09-11
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 PCMG routines
Table of Contents for all manual pages
Index of all manual pages