SNESGetLagPreconditioner

Return how often the preconditioner is rebuilt

Synopsis

#include "petscsnes.h"  
PetscErrorCode SNESGetLagPreconditioner(SNES snes, PetscInt *lag)

Not Collective

Input Parameter

• snes - the SNES context

Output Parameter

• lag - -1 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within a single nonlinear solve, 2 means every second time the Jacobian is built etc. -2 indicates rebuild preconditioner at next chance but then never rebuild after that

Notes

The default is 1

The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1

See Also

SNES: Nonlinear Solvers, SNES, SNESSetTrustRegionTolerance(), SNESSetLagPreconditioner(), SNESSetLagJacobianPersists(), SNESSetLagPreconditionerPersists()

Level

intermediate

Location

src/snes/interface/snes.c

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Index of all SNES routines
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Index of all manual pages