slepc-3.22.2 2024-12-02

NEPNArnoldiSetLagPreconditioner

Determines when the preconditioner is rebuilt in the nonlinear solve.

#include "slepcnep.h" 
PetscErrorCode NEPNArnoldiSetLagPreconditioner(NEP nep,PetscInt lag)

Logically Collective

	nep	- nonlinear eigenvalue solver
	lag	- 0 indicates NEVER rebuild, 1 means rebuild every time the Jacobian is computed within the nonlinear iteration, 2 means every second time the Jacobian is built, etc.

-nep_narnoldi_lag_preconditioner <lag>

- the lag value

The default is 1. The preconditioner is ALWAYS built in the first iteration of a nonlinear solve.

intermediate