PCSORSetSymmetric
Sets the SOR preconditioner to use symmetric (SSOR), backward, or forward relaxation. The local variants perform SOR on each processor. By default forward relaxation is used.
Synopsis
int PCSORSetSymmetric(PC pc, MatSORType flag)
Collective on
PC
Input Parameters
pc | - the preconditioner context
|
flag | - one of the following
|
SOR_FORWARD_SWEEP
SOR_BACKWARD_SWEEP
SOR_SYMMETRIC_SWEEP
SOR_LOCAL_FORWARD_SWEEP
SOR_LOCAL_BACKWARD_SWEEP
SOR_LOCAL_SYMMETRIC_SWEEP
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
Notes
To use the Eisenstat trick with SSOR, employ the PCEISENSTAT preconditioner,
which can be chosen with the
option
-pc_type eisenstat -Activates Eisenstat trick
Keywords
PC, SOR, SSOR, set, relaxation, sweep, forward, backward, symmetric
See Also
PCEisenstatSetOmega(), PCSORSetIterations(), PCSORSetOmega()
Location: src/pc/impls/sor/sor.c
PC Index
Table of Contents