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
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