PCEisenstatSetOmega
Sets the SSOR relaxation coefficient, omega, to use with Eisenstat's trick (where omega = 1.0 by default).
Synopsis
int PCEisenstatSetOmega(PC pc,double omega)
Input Parameters
pc | - the preconditioner context
|
omega | - relaxation coefficient (0 < omega < 2)
|
Collective on
PC
Options Database Key
-pc_eisenstat_omega <omega> -Sets omega
Notes
The Eisenstat trick implementation of SSOR requires about 50% of
theusual amount of floating point operations used for SSOR + Krylov method;
however, the preconditioned problem must be solved with both
leftand right preconditioning.
To use SSOR without the Eisenstat trick, employ the PCSOR preconditioner,
which can be chosen with the database
options
-pc_type sor -pc_sor_symmetric
Keywords
PC, Eisenstat, set, SOR, SSOR, relaxation, omega
See Also
PCSORSetOmega()
Location: src/pc/impls/eisen/eisen.c
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