[petsc-users] KSP convergence problem

[Mark F. Adams]

On Mar 20, 2013, at 2:12 PM, Mehrdad H Farahani <mh.farahani at gmail.com> wrote:

> I'm experience a weird convergence problem with bcgsl with both ILU and GAMG preconditioning. The problem converges normally (at least in the preconditioned norm), but then kicks out with converged reason = -4. I've attached the convergence history of the previous time-step which worked and the timestep which shows problems. Could someone give me an idea on how to proceed?
> 

Did you run with -ksp_converged_reason ?

I don't know were this -4 comes from.  Could this be from your code?

> Best Regards
> 
> -- 
> Mehrdad 
> 
> 
> <convergence>