This variant is not "explicitly normalized" like PGMRES, and requires a shift parameter.
A heuristic for choosing the shift parameter is the largest eigenvalue of the preconditioned operator.
Only right preconditioning is supported (but this preconditioner may be nonlinear, as with FGMRES)
-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 | |
-ksp_pipefgmres_shift | - the shift to use (defaults to 1. See KSPPIPEFGMRESSetShift() vectors are allocated as needed) | |
-ksp_gmres_krylov_monitor | - plot the Krylov space generated |
Developer Notes: This object is subclassed off of KSPGMRES
Level:beginner
Location:src/ksp/ksp/impls/gmres/pipefgmres/pipefgmres.c
Index of all KSP routines
Table of Contents for all manual pages
Index of all manual pages