On Tue, Sep 26, 2017 at 8:59 AM, Praveen C <[email protected]> wrote:
> Thank you. I had to do this > > ierr = SNESSetLagJacobian(snes,-2); CHKERRQ(ierr); > ierr = SNESSetLagPreconditioner(snes,-2); CHKERRQ(ierr); > > Now I see that my FormJacobian function is called only once. Is this > correct way to use it ? > Yes Matt > Best > praveen > > On Tue, Sep 26, 2017 at 6:00 PM, Matthew Knepley <[email protected]> > wrote: > >> On Tue, Sep 26, 2017 at 8:28 AM, Praveen C <[email protected]> wrote: >> >>> Dear all >>> >>> I am solving a nonlinear problem using matrix-free approach in snes and >>> I give a preconditioner matrix via SNESSetJacobian. My preconditioner is >>> based on a first order scheme which is linear and hence preconditioner >>> matrix will not change. How do I tell snes not to recompute it ? >>> >> >> http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/ >> SNES/SNESSetLagPreconditioner.html >> >> Matt >> >> >>> Thanks >>> praveen >>> >> >> >> >> -- >> What most experimenters take for granted before they begin their >> experiments is infinitely more interesting than any results to which their >> experiments lead. >> -- Norbert Wiener >> >> https://www.cse.buffalo.edu/~knepley/ <http://www.caam.rice.edu/~mk51/> >> > > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener https://www.cse.buffalo.edu/~knepley/ <http://www.caam.rice.edu/~mk51/>
