[petsc-users] HYPRE BOOMERAMG no output

[Hao Zhang]

Thanks. Barry.



On Tue, Dec 12, 2017 at 2:03 PM, Smith, Barry F. <bsmith at mcs.anl.gov> wrote:

>
>
> > On Dec 12, 2017, at 12:04 PM, Hao Zhang <hbcbh1999 at gmail.com> wrote:
> >
> > hi,
> >
> > before I introduce HYPRE with BOOMERAMG to my CFD code, I will have
> output with good convergence rate. with BOOMERAMG, the same code will take
> longer time to run and there's a good chance that no output will be
> produced whatsoever.
>
>   Are you running with -ksp_monitor -ksp_view_pre -ksp_converged_reason ?
>
>   If you are using -ksp_monitor and getting no output it could be that
> hypre is taking a very long time to form the AMG preconditioner, but I
> won't expect to see this unless the problem is very very big.
>
>    You can always run with -start_in_debugger and then type cont in the
> debugger wait a couple minutes and then use control C in the debugger and
> type where to determine what it is doing at the time (you can email the
> output to petsc-maint at mcs.anl.gov).
>
>    Boomeramg is not good for all classes of matrices, it is fine for
> elliptic/parabolic generally but if you hand it something that is
> hyperbolically dominated it will not work well.
>
>    Barry
>
> >
> > what happened? thanks!
> >
> > --
> > Hao Zhang
> > Dept. of Applid Mathematics and Statistics,
> > Stony Brook University,
> > Stony Brook, New York, 11790
>
>


-- 
Hao Zhang
Dept. of Applid Mathematics and Statistics,
Stony Brook University,
Stony Brook, New York, 11790
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