verbose mode for nonlinear solve?

[walkersw]

When solving a nonlinear variational problem, is there a "verbose" option? For instance, to see how many Newton iterations it takes? It would be useful to have for debugging. When I use "solve(F == 0)" now, it is silent.

[pefarrell]

You can do solve(F == 0, u, bcs, solver_parameters={"snes_monitor": None}) to get PETSc to tell you what's happening. (I wonder if this should be the default.)

[walkersw]

Thanks for the super-fast response. Seems weird that None tells it to output info, but whatever.

[pefarrell]

I agree it's slightly weird. It's because PETSc has options that take arguments (like -ksp_type cg) and options that don't (like -ksp_monitor_true_residual or -snes_monitor). The former get translated into {"ksp_type": "cg"} and the latter into {"snes_monitor": None}.