PCFieldSplitSchurPrecondition
Indicates if the Schur complement is preconditioned by a preconditioner constructed by the D matrix. Otherwise no preconditioner is used.
Synopsis
#include "petscpc.h"
PetscErrorCode PETSCKSP_DLLEXPORT PCFieldSplitSchurPrecondition(PC pc,PCFieldSplitSchurPreType ptype,Mat pre)
Collective on PC
Input Parameters
| pc | - the preconditioner context
|
| ptype | - which matrix to use for preconditioning the Schur complement
|
| userpre | - matrix to use for preconditioning, or PETSC_NULL
|
Notes
The default is to use the block on the diagonal of the preconditioning matrix. This is D, in the (1,1) position.
There are currently no preconditioners that work directly with the Schur complement so setting
PC_FIELDSPLIT_SCHUR_PRE_SELF is observationally equivalent to -fieldsplit_1_pc_type none.
Options Database
-pc_fieldsplit_schur_precondition <self,user,diag> default is diag -
See Also
PCFieldSplitGetSubKSP(), PCFIELDSPLIT, PCFieldSplitSetFields(), PCFieldSplitSchurPreType
Level:intermediate
Location:src/ksp/pc/impls/fieldsplit/fieldsplit.c
Index of all PC routines
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