petsc-3.7.1 2016-05-15
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KSPGMRES

Implements the Generalized Minimal Residual method. (Saad and Schultz, 1986) with restart

Options Database Keys

-ksp_gmres_restart <restart> - the number of Krylov directions to orthogonalize against Many br
-ksp_gmres_haptol <tol> - sets the tolerance for "happy ending" (exact convergence) Many br
-ksp_gmres_preallocate - preallocate all the Krylov search directions initially (otherwise groups of Many brvectors are allocated as needed) Many br
-ksp_gmres_classicalgramschmidt - use classical (unmodified) Gram-Schmidt to orthogonalize against the Krylov space (fast) (the default) Many br
-ksp_gmres_modifiedgramschmidt - use modified Gram-Schmidt in the orthogonalization (more stable, but slower) Many br
-ksp_gmres_cgs_refinement_type <never,ifneeded,always> - determine if iterative refinement is used to increase the Many brstability of the classical Gram-Schmidt orthogonalization. Many br
-ksp_gmres_krylov_monitor - plot the Krylov space generated Many br

Many br

Notes: Left and right preconditioning are supported, but not symmetric preconditioning. Many br

References

1. -YOUCEF SAAD AND MARTIN H. SCHULTZ, GMRES: A GENERALIZED MINIMAL RESIDUAL ALGORITHM FOR SOLVING NONSYMMETRIC LINEAR SYSTEMS. Many brSIAM J. ScI. STAT. COMPUT. Vo|. 7, No. 3, July 1986. Many br

See Also

KSPCreate(), KSPSetType(), KSPType (for list of available types), KSP, KSPFGMRES, KSPLGMRES,
KSPGMRESSetRestart(), KSPGMRESSetHapTol(), KSPGMRESSetPreAllocateVectors(), KSPGMRESSetOrthogonalization(), KSPGMRESGetOrthogonalization(), Many brKSPGMRESClassicalGramSchmidtOrthogonalization(), KSPGMRESModifiedGramSchmidtOrthogonalization(), Many brKSPGMRESCGSRefinementType, KSPGMRESSetCGSRefinementType(), KSPGMRESGetCGSRefinementType(), KSPGMRESMonitorKrylov(), KSPSetPCSide() Many br

Level:beginner
Location:
src/ksp/ksp/impls/gmres/gmres.c
Index of all KSP routines
Table of Contents for all manual pages
Index of all manual pages

Examples

src/ksp/ksp/examples/tutorials/ex7.c.html
src/ksp/ksp/examples/tutorials/ex8.c.html
src/ksp/ksp/examples/tutorials/ex62.c.html
src/tao/pde_constrained/examples/tutorials/hyperbolic.c.html