PCFieldSplitSetDetectSaddlePoint#

Sets flag indicating whether PCFIELDSPLIT will attempt to automatically determine fields based on zero diagonal entries.

Synopsis#

#include "petscpc.h" 
PetscErrorCode PCFieldSplitSetDetectSaddlePoint(PC pc, PetscBool flg)

Logically Collective

Input Parameter#

pc - the preconditioner context

Output Parameter#

flg - boolean indicating whether to detect fields or not

Options Database Key#

-pc_fieldsplit_detect_saddle_point - detect and use the saddle point

Note#

Also sets the split type to PC_COMPOSITE_SCHUR (see PCFieldSplitSetType()) and the Schur preconditioner type to PC_FIELDSPLIT_SCHUR_PRE_SELF (see PCFieldSplitSetSchurPre()).

See Also#

Solving Block Matrices, PC, PCFIELDSPLIT, PCFieldSplitGetDetectSaddlePoint(), PCFieldSplitSetType(), PCFieldSplitSetSchurPre(), PC_FIELDSPLIT_SCHUR_PRE_SELF

Level#

Intermediate

Location#

src/ksp/pc/impls/fieldsplit/fieldsplit.c

Examples#

src/dm/impls/stag/tutorials/ex2.c
src/dm/impls/stag/tutorials/ex3.c

Index of all PC routines
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Index of all manual pages