petsc-3.14.6 2021-03-30
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SNESGetLagJacobian

 Indicates 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 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.

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

SNESSetTrustRegionTolerance(), SNESSetLagJacobian(), SNESSetLagPreconditioner(), SNESGetLagPreconditioner(), SNESSetLagJacobianPersists(), SNESSetLagPreconditionerPersists()

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