petsc-3.8.4 2018-03-24
Report Typos and Errors


Indicates how often the Jacobian is rebuilt. See SNESGetLagPreconditioner() to determine when the preconditioner is rebuilt


#include "petscsnes.h"  
PetscErrorCode  SNESGetLagJacobian(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.

Options Database Keys

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


SNES, nonlinear, set, convergence, tolerances

See Also

SNESSetTrustRegionTolerance(), SNESSetLagJacobian(), SNESSetLagPreconditioner(), SNESGetLagPreconditioner()

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