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
Input Parameters#
pc - the multigrid context
rscale - the scaling
l - the level (0 is coarsest) to supply [Do not supply 0]
Note#
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#
KSP: Linear System Solvers, PCMG, PCMGSetInterpolation(), PCMGGetRestriction(), PCMGGetInjection()
Level#
advanced
Location#
Index of all PC routines
Table of Contents for all manual pages
Index of all manual pages