[aspect-devel] problem with ASPECT - the iterative Stokes solver did not converge

[Petar Glisovic]

Wolfgang,

First of all, thank you for your quick reply.

This is almost certainly an unrelated observation, but with as few unknowns
> as you have, you should first run small models using only a single
> processor when you try things out.
>
> My rule of thumb is that you can run models with a few 100,000 unknowns on
> a single processor. For parallel computations, you typically don't gain
> anything if you have fewer than 50,000 unknowns per processor -- i.e., in
> your case, 4 or 5 processors is about the optimum.
>

Thanks for this tip.


subsection Material model
>>      set Model name = Steinberger
>>      subsection Steinberger model
>>          set Bilinear interpolation = true
>>          set Compressible = true
>
> What happens if you set this to false?
>

The outcome of this action is:
--------------------------------------------------------
An error occurred in line <3369> of file </RQusagers/glisovic
/deal.II/include/deal.II/lac/trilinos_sparse_matrix.h> in function
    void dealii::TrilinosWrappers::SparseMatrix::add(dealii::
TrilinosWrappers::SparseMatrix::size_type, dealii::TrilinosWrappers::
SparseMatrix::size_type, const size_type*, const double*, bool, bool)
The violated condition was:
    numbers::is_finite(values[j])
The name and call sequence of the exception was:
    ExcNumberNotFinite()
Additional Information:
(none)
...
The complete log file is attached below.

Petar



On Fri, Jul 25, 2014 at 4:14 PM, Wolfgang Bangerth <bangerth at math.tamu.edu>
wrote:

>
> Petar,
> let me pull this discussion to the mailing list since the authors of the
> Steinberger model are there.
>
>
>  I have experienced a problem running ASPECT. It seems that the iterative
>> Stokes solver did not converge after three days of the job running on 48
>> CPUs - please see attached log files (/aspect.e2477653, aspect.o2477653
>> & log.txt/).
>>
>
> This is almost certainly an unrelated observation, but with as few
> unknowns as you have, you should first run small models using only a single
> processor when you try things out.
>
> My rule of thumb is that you can run models with a few 100,000 unknowns on
> a single processor. For parallel computations, you typically don't gain
> anything if you have fewer than 50,000 unknowns per processor -- i.e., in
> your case, 4 or 5 processors is about the optimum.
>
>  However, my goal is to use the depth-dependent (i.e., radial) viscosity
>> profile (Mitrovica & Forte, 2004; please see attached file:
>> /mitro-forte-2004-radial-visc-new.txt/) jointly with lateral variations
>> in viscosity (see below /shell_simple_3d_new.prm/). For example, to use
>>
>> something similar to the Steinberger model:
>> subsection Material model
>>      set Model name = Steinberger
>>      subsection Steinberger model
>>          set Bilinear interpolation = true
>>          set Compressible = true
>>
>
> What happens if you set this to false?
>
> I don't know the parameters to the Steinberger model, so can't comment on
> their validity. I hope someone else on the mailing list may be able to
> provide more feedback.
>
> Best
>   Wolfgang
> --
> ------------------------------------------------------------------------
> Wolfgang Bangerth               email:            bangerth at math.tamu.edu
>                                 www: http://www.math.tamu.edu/~bangerth/
>
>


-- 
Petar Glisovic, Dr.
postdoctoral fellow

*address*:  GEOTOP, Université du Québec à Montréal, CP 8888, succursale
Centre-Ville, Montréal, Québec, Canada H3C 3P8 * | ema**il**: *
pglisovic at gmail.com & glisovic.petar at courrier.uqam.ca*  | phone:
*1-514-987-3000
#3592 & #4600*  | fax:  *1-514-987-3635
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