PCEISENSTAT#
An implementation of SSOR (symmetric successive over relaxation, symmetric Gauss-Seidel) preconditioning that incorporates Eisenstat’s trick to reduce the amount of computation needed.
Options Database Keys#
-pc_eisenstat_omega
- Sets omega-pc_eisenstat_no_diagonal_scaling - Activates
PCEisenstatSetNoDiagonalScaling()
Notes#
Only implemented for the MATAIJ matrix format.
Not a true parallel SOR, in parallel this implementation corresponds to block Jacobi with SOR on each block.
Developer Note#
Since this algorithm runs the Krylov method on a transformed linear system the implementation provides PCPreSolve() and PCPostSolve()
routines that KSP uses to set up the transformed linear system.
See Also#
KSP: Linear System Solvers, PCCreate(), PCSetType(), PCType, PC, PCEisenstatGetOmega(),
PCEisenstatSetNoDiagonalScaling(), PCEisenstatSetOmega(), PCSOR
Level#
beginner
Location#
src/ksp/pc/impls/eisens/eisen.c
Index of all PC routines
Table of Contents for all manual pages
Index of all manual pages