PCFieldSplitSetGKBTol#

Sets the solver tolerance for the generalized Golub-Kahan bidiagonalization preconditioner in PCFIELDSPLIT

Synopsis#

#include "petscpc.h" 
PetscErrorCode PCFieldSplitSetGKBTol(PC pc, PetscReal tolerance)

Collective

Input Parameters#

  • pc - the preconditioner context

  • tolerance - the solver tolerance

Options Database Key#

  • -pc_fieldsplit_gkb_tol - default is 1e-5

Note#

The generalized GKB algorithm uses a lower bound estimate of the error in energy norm as stopping criterion. It stops once the lower bound estimate undershoots the required solver tolerance. Although the actual error might be bigger than this estimate, the stopping criterion is satisfactory in practical cases [A13].

References#

[Ar13] Generalized Golub-Kahan bidiagonalization and stopping criteria, SIAM J. Matrix Anal. Appl., Vol. 34, No. 2, pp. 571-592, 2013.

See Also#

Solving Block Matrices, PC, PCFIELDSPLIT, PCFieldSplitSetGKBDelay(), PCFieldSplitSetGKBNu(), PCFieldSplitSetGKBMaxit()

Level#

intermediate

Location#

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

Implementations#

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

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