On Fri, 2 Jul 2010 14:08:14 -0400, Xuan YU <xxy113 at psu.edu> wrote: > If I don't provide Jacobian, it will be: type: euler > total number > of nonlinear solver iterations=0 > total number > of linear solver iterations=0
The default TS is the simplest possible integrator, forward Euler. Of course this doesn't do any solves (no SNES) and is not appropriate for stiff systems. Run with -ts_type theta for something more likely to work (and which will use SNES). > [0]PETSC ERROR: Floating point exception! > [0]PETSC ERROR: User provided compute function generated a Not-a-Number! Euler is unstable for your problem, this should have nothing to do with the way you specified the Jacobian. Jed
