Skip to main content
`Ctrl`+`K`

# KSPFBCGSR

Implements a mathematically equivalent variant of flexible bi-CG-stab, `KSPFBCGS`. Flexible Krylov Methods

## Notes

This implementation requires fewer `MPI_Allreduce()` calls than `KSPFBCGS` and may converge faster

See `KSPPIPEBCGS` for a pipelined version of the algorithm

Flexible BiCGStab, unlike most Krylov methods, allows the preconditioner to be nonlinear, that is the action of the preconditioner to a vector need not be linear in the vector entries.

Only supports right preconditioning

## See Also

KSP: Linear System Solvers, Flexible Krylov Methods, `KSPFBCGSR`, `KSPPIPEBCGS`, `KSPBCGSL`, `KSPBCGS`, `KSPCreate()`, `KSPSetType()`, `KSPType`, `KSP`, `KSPBICG`, `KSPFBCGS`, `KSPSetPCSide()`

## Level

beginner

## Location

src/ksp/ksp/impls/bcgs/fbcgsr/fbcgsr.c

Index of all KSP routines
Table of Contents for all manual pages
Index of all manual pages