| -ksp_gmres_restart <restart> | - the number of Krylov directions to orthogonalize against | |
| -ksp_gmres_haptol <tol> | - sets the tolerance for "happy ending" (exact convergence) | |
| -ksp_gmres_preallocate | - preallocate all the Krylov search directions initially (otherwise groups of vectors are allocated as needed) | |
| -ksp_gmres_classicalgramschmidt | - use classical (unmodified) Gram-Schmidt to orthogonalize against the Krylov space (fast) (the default) | |
| -ksp_gmres_modifiedgramschmidt | - use modified Gram-Schmidt in the orthogonalization (more stable, but slower) | |
| -ksp_gmres_cgs_refinement_type <never,ifneeded,always> | - determine if iterative refinement is used to increase the stability of the classical Gram-Schmidt orthogonalization. | |
| -ksp_gmres_krylov_monitor | - plot the Krylov space generated | |
| -ksp_fgmres_modifypcnochange | - do not change the preconditioner between iterations | |
| -ksp_fgmres_modifypcksp | - modify the preconditioner using KSPFGMRESModifyPCKSP() |
Notes: See KSPFGMRESSetModifyPC() for how to vary the preconditioner between iterations Only right preconditioning is supported.
Notes: The following options -ksp_type fgmres -pc_type ksp -ksp_ksp_type bcgs -ksp_view -ksp_pc_type jacobi make the preconditioner (or inner solver) be bi-CG-stab with a preconditioner of Jacobi.
Developer Notes: This object is subclassed off of KSPGMRES
Level:beginner
Location:src/ksp/ksp/impls/gmres/fgmres/fgmres.c
Index of all KSP routines
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Index of all manual pages