Only supports left preconditioning.
The natural norm for this method is (u,Au). This norm is available at no computational costs. Choosing norm types preconditioned or unpreconditioned involves a blocking reduction which prevents any benefit from pipelining.
-ksp_pipegcr_mmax <N> | - the max number of Krylov directions to orthogonalize against | |
-ksp_pipegcr_unroll_w | - unroll w at the storage cost of a maximum of (mmax+1) extra vectors with the benefit of better pipelining (default: PETSC_TRUE) | |
-ksp_pipegcr_nprealloc <N> | - the number of vectors to preallocated for storing Krylov directions. Once exhausted new directions are allocated blockwise (default: 5) | |
-ksp_pipegcr_truncation | - Truncate number of previous Krylov directions | |
-ksp_pipegcr_trancation_restart | - Truncation-restart strategy: Keep at most mmax Krylov directions then restart (the default) |
Level:beginner
Location:src/ksp/ksp/impls/gcr/pipegcr/pipegcr.c
Index of all KSP routines
Table of Contents for all manual pages
Index of all manual pages