PCEisenstatSetNoDiagonalScaling#
Causes the Eisenstat preconditioner, PCEISENSTAT
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
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 KSPSetDiagonalScaling()
or -ksp_diagonal_scale option then you will
likely want to use this routine since it will save you some unneeded flops.
See Also#
KSP: Linear System Solvers, PCEisenstatSetOmega()
, PCEISENSTAT
Level#
intermediate
Location#
Implementations#
PCEisenstatSetNoDiagonalScaling_Eisenstat() in src/ksp/pc/impls/eisens/eisen.c
Index of all PC routines
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Index of all manual pages