petsc-3.7.1 2016-05-15
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SNESSetLagPreconditioner

Determines when the preconditioner is rebuilt in the nonlinear solve.

Synopsis

#include "petscsnes.h"  
PetscErrorCode  SNESSetLagPreconditioner(SNES snes,PetscInt lag)
Logically Collective on SNES Many br

Input Parameters

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

Options Database Keys

-snes_lag_preconditioner <lag> - Many brNotes: Many brThe default is 1 Many brThe preconditioner is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 Many brIf -1 is used before the very first nonlinear solve the preconditioner is still built because there is no previous preconditioner to use Many br

Many br

Keywords

SNES, nonlinear, set, convergence, tolerances

See Also

SNESSetTrustRegionTolerance(), SNESGetLagPreconditioner(), SNESSetLagJacobian(), SNESGetLagJacobian()

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