Are you wanting an analytic matrix-free operator or one created for you based on finite differencing? If the latter, just use -snes_mf or -snes_mf_operator.
https://petsc.org/release/manual/snes/#jacobian-evaluation Yi Hu <y...@mpie.de> writes: > Dear PETSc team, > > My solution scheme relies on a matrix-free jacobian in the SNES solver. I > saw the useful C interface like MatCreateSNESMF(), DMSNESCreateJacobianMF(). > I am wondering if you have the fortran equivalence? > > I think for my problem in the main program I need to do > DMDASNESsetJacobianLocal(DM, INSERT_VALUES, myJacobian, ctx, err_petsc). Then > in myJacobian() subroutine I have to create the operator from > DMSNESCreateJacobianMF(), and register my own MATOP_MULT from > MatShellSetOperation(). Am I correct? > > Are these fortran subroutines available? I saw an example in ts module as > ex22f_mf.F90 which behaves similar as what I would like to do. Because I > would like to use ngmres, I then need to stay in the SNES. > > Thanks for your help. > > Best wishes, > Yi > > ------------------------------------------------- > Stay up to date and follow us on LinkedIn, Twitter and YouTube. > > Max-Planck-Institut für Eisenforschung GmbH > Max-Planck-Straße 1 > D-40237 Düsseldorf > > Handelsregister B 2533 > Amtsgericht Düsseldorf > > Geschäftsführung > Prof. Dr. Gerhard Dehm > Prof. Dr. Jörg Neugebauer > Prof. Dr. Dierk Raabe > Dr. Kai de Weldige > > Ust.-Id.-Nr.: DE 11 93 58 514 > Steuernummer: 105 5891 1000 > > > Please consider that invitations and e-mails of our institute are > only valid if they end with …@mpie.de. > If you are not sure of the validity please contact r...@mpie.de > > Bitte beachten Sie, dass Einladungen zu Veranstaltungen und E-Mails > aus unserem Haus nur mit der Endung …@mpie.de gültig sind. > In Zweifelsfällen wenden Sie sich bitte an r...@mpie.de > -------------------------------------------------
