petsc-3.6.1 2015-08-06
PCEisenstatGetNoDiagonalScaling
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 PCEisenstatGetNoDiagonalScaling(PC pc,PetscBool *flg)
Logically Collective on PC
Input Parameter
pc -the preconditioner context
Output Parameter
flg -PETSC_TRUE means there is no diagonal scaling applied
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
PCEisenstatGetOmega()
Level:intermediate
Location:src/ksp/pc/impls/eisens/eisen.c
Index of all PC routines
Table of Contents for all manual pages
Index of all manual pages