SNESGetLagJacobian#
Get how often the Jacobian is rebuilt. See SNESGetLagPreconditioner() to determine when the preconditioner is rebuilt
Synopsis#
#include "petscsnes.h"
PetscErrorCode SNESGetLagJacobian(SNES snes, PetscInt *lag)
Not Collective
Input Parameter#
snes - the
SNEScontext
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.
Notes#
The default is 1
The jacobian is ALWAYS built in the first iteration of a nonlinear solve unless lag is -1 or SNESSetLagJacobianPersists() was called.
See Also#
SNES: Nonlinear Solvers, SNES, SNESSetTrustRegionTolerance(), SNESSetLagJacobian(), SNESSetLagPreconditioner(), SNESGetLagPreconditioner(), SNESSetLagJacobianPersists(), SNESSetLagPreconditionerPersists()
Level#
intermediate
Location#
Index of all SNES routines
Table of Contents for all manual pages
Index of all manual pages