[petsc-users] infinite loop with NEWTONTR?

[Barry Smith]

On Apr 25, 2014, at 7:31 AM, Norihiro Watanabe <norihiro.w at gmail.com> wrote:

> Hi, 
> 
> In my simulation, nonlinear solve with the trust regtion method got stagnent after linear solve (see output below).

   What do you mean, get stagnant? Does the code just hang, that is keep running but not print anything.

> Is it possible that the method goes to inifite loop?

   This is not suppose to be possible.

> Is there any parameter to avoid this situation?

  You need to determine what it is “hanging” on. Try running with -start_in_debugger and when it “hangs” hit control C and type where to determine where it is.

   Barry

> 
>   0 SNES Function norm 1.828728087153e+03 
>     0 KSP Residual norm 91.2735 
>     Linear solve converged due to CONVERGED_ITS iterations 1
>     Linear solve converged due to CONVERGED_RTOL iterations 3
>     1 KSP Residual norm 3.42223 
>   Linear solve converged due to CONVERGED_STEP_LENGTH iterations 1
> 
> 
> Thank you in advance,
> Nori