What is the output from
-snes_monitor -ksp_monitor_true_residual -pc_type lu -ksp_converged_reason
-snes_converged_reason
> On Jun 30, 2017, at 3:45 AM, Maximilian Hartig <[email protected]>
> wrote:
>
> Hello,
>
> I’m trying to implement plasticity and have problems getting the Petsc SNES
> to converge. To check if my residual formulation is correct I tried running
> with -snes_fd for an easy example as the Petsc FAQ suggest. I cannot seem to
> get the solver to converge at any cost.
> I already tried to impose bounds on the solution and moved to vinewtonrsls as
> a nonlinear solver. I checked and rechecked my residuals but I do not find an
> error there. I now have the suspicion that the -snes_fd option is not made
> for handling residuals who’s first derivatives are not continuous (e.g. have
> an “if” condition in them for the plasticity/ flow-condition). Can you
> confirm my suspicion? And is there another way to test my residual
> formulation separate from my hand-coded jacobian?
>
>
> Thanks,
> Max
