[petsc-users] DIVERGED_FNORM_NAN

Alexander Lindsay adlinds3 at ncsu.edu
Thu Sep 17 09:24:51 CDT 2015


It solved beautifully with MUMPS. Thank you Matt!

Alex

On 09/16/2015 10:58 AM, Matthew Knepley wrote:
> On Wed, Sep 16, 2015 at 8:28 AM, Alexander Lindsay <adlinds3 at ncsu.edu 
> <mailto:adlinds3 at ncsu.edu>> wrote:
>
>     Hi all,
>
>     I've built a MOOSE application and the problem I'm studying solves
>     great using serial LU. However, when I try to solve in parallel
>     using super LU, I encounter many DIVERGED_LINE_SEARCH errors using
>     the default bt line search. If I switch to line_search=none, then
>     instead of DIVERGED_LINE_SEARCH errors I get DIVERGED_FNORM_NAN
>     errors. I do not have a lot of debugging experience, but I am
>     slowly gaining more. Is there a good way to get more information
>     about what's causing the NAN's? I.e. a specific residual or
>     jacobian statement?
>
>     This may not even be an appropriate list to post this problem in
>     (could be more on the MOOSE side); apologies if that's the case.
>
>
> The NaN means something has gone wrong. However, there are a few 
> SuperLU_dist bugs that we know of. You could try:
>
>   - Upgrading PETSc to the latest patch, which should download the 
> fixed SuperLU_dist
>
>   - Trying MUMPS instead
>
>   Thanks,
>
>      Matt
>
>     Alex
>
>
>
>
> -- 
> What most experimenters take for granted before they begin their 
> experiments is infinitely more interesting than any results to which 
> their experiments lead.
> -- Norbert Wiener

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