petsc-3.11.4 2019-09-28
PCEisenstatSetNoDiagonalScaling
Causes the Eisenstat preconditioner not to do additional diagonal preconditioning. For matrices with a constant along the diagonal, this may save a small amount of work.
Synopsis
#include "petscpc.h"
PetscErrorCode PCEisenstatSetNoDiagonalScaling(PC pc,PetscBool flg)
Logically Collective on PC
Input Parameters
| pc | - the preconditioner context
|
| flg | - PETSC_TRUE turns off diagonal scaling inside the algorithm
|
Options Database Key
-pc_eisenstat_no_diagonal_scaling -Activates PCEisenstatSetNoDiagonalScaling()
Note
If you use the KPSSetDiagonalScaling() or -ksp_diagonal_scale option then you will
likley want to use this routine since it will save you some unneeded flops.
Keywords
PC, Eisenstat, use, diagonal, scaling, SSOR
See Also
PCEisenstatSetOmega()
Level
intermediate
Location
src/ksp/pc/impls/eisens/eisen.c
Implementations
PCEisenstatSetNoDiagonalScaling_Eisenstat in src/ksp/pc/impls/eisens/eisen.c
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