On Sat, Dec 11, 2021 at 1:58 PM Tang, Qi <[email protected]> wrote: > Hi, > Does anyone have comment on finite difference coloring with DMStag? We are > using DMStag and TS to evolve some nonlinear equations implicitly. It would > be helpful to have the coloring Jacobian option with that. >
Since DMStag produces the Jacobian connectivity, you can use -snes_fd_color_use_mat. It has many options. Here is an example of us using that: https://gitlab.com/petsc/petsc/-/blob/main/src/snes/tutorials/ex19.c#L898 Thanks, Matt > Thanks, > Qi > > > On Oct 15, 2021, at 3:07 PM, Jorti, Zakariae via petsc-users < > [email protected]> wrote: > > Hello, > > Does the Jacobian approximation using coloring and finite differencing of > the function evaluation work in DMStag? > Thank you. > Best regards, > > Zakariae > > > -- 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.cse.buffalo.edu/~knepley/>
