petsc-3.7.7 2017-09-25
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Indicates how often the preconditioner is rebuilt


#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

Options Database Keys

-snes_lag_preconditioner <lag> - Notes: The default is 1 The preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1


SNES, nonlinear, set, convergence, tolerances

See Also

SNESSetTrustRegionTolerance(), SNESSetLagPreconditioner()

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