[petsc-users] Using -ts_type sundials with -snes-fd

[Geoff Oxberry]

Running the following example from PETSC 3.3.0-dev (changeset: 23631:0e86ac5e4170)

/path/to/petsc-dev/src/ts/examples/tutorials/ex8 -problem_type rober -snes_fd -ts_type sundials

gives the following output

steps 1000 (0 rejected, 0 SNES fails), ftime 744.845, nonlinits 3739, linits 3739
WARNING! There are options you set that were not used!
WARNING! could be spelling mistake, etc!
Option left: name:-snes_fd no value 

Just to confirm, is it currently impossible to use a finite difference Jacobian matrix in concert with CVODE? If so, could this feature be implemented in a future release? I currently rely on Sundials to integrate stiff systems of ODEs, and for my application, it is impractical to derive an analytical Jacobian matrix. (It is an issue I've discussed both with Jed and Matt on another forum.)

Cheers,

Geoff