petsc-3.10.5 2019-03-28
SNESGetLagPreconditioner
Indicates 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
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
Keywords
SNES, nonlinear, set, convergence, tolerances
See Also
SNESSetTrustRegionTolerance(), SNESSetLagPreconditioner()
Level
intermediate
Location
src/snes/interface/snes.c
Index of all SNES routines
Table of Contents for all manual pages
Index of all manual pages