PCSORGetSymmetric#
Gets the form the SOR preconditioner is using; backward, or forward relaxation. The local variants perform SOR on each processor. By default forward relaxation is used.
Synopsis#
#include "petscpc.h" 
PetscErrorCode PCSORGetSymmetric(PC pc, MatSORType *flag)
Logically Collective
Input Parameter#
- pc - the preconditioner context 
Output Parameter#
- flag - one of the following 
Options Database Keys#
- -pc_sor_symmetric - Activates symmetric version 
- -pc_sor_backward - Activates backward version 
- -pc_sor_local_forward - Activates local forward version 
- -pc_sor_local_symmetric - Activates local symmetric version 
- -pc_sor_local_backward - Activates local backward version 
Note#
To use the Eisenstat trick with SSOR, employ the PCEISENSTAT preconditioner,
which can be chosen with the option
- -pc_type eisenstat - Activates Eisenstat trick 
See Also#
KSP: Linear System Solvers, PCSOR, PCEisenstatSetOmega(), PCSORSetIterations(), PCSORSetOmega(), PCSORSetSymmetric()
Level#
intermediate
Location#
Implementations#
PCSORGetSymmetric_SOR() in src/ksp/pc/impls/sor/sor.c
Index of all PC routines
Table of Contents for all manual pages
Index of all manual pages