[petsc-users] preconditioner for -snes_fd or -snes_fd_color

[Xiangdong]

Hello everyone,

If we use -snes_fd or -snes_fd_color, can we still pass a preconditioner to
snes/ksp?

In snes/ex1.c, when I use -snes_fd, the program never calls the
FormJacobian1 to get the preconditioner.

Any suggestions about providing preconditioner to snes_fd or snes_fd_color?

Thanks.

Xiangdong