[aspect-devel] problem with ASPECT - the iterative Stokes solver did not converge
Petar Glisovic
pglisovic at gmail.com
Mon Aug 4 13:16:06 PDT 2014
@Wolfgang or @list moderator
I didn't receive either Rene or Jacky's message. Checking the aspect-devel
archives I have found out that there are these two messages intended for
me. However, I have subscribed to the aspect-devel list and I hope this
will prevent the communication problems in the future.
@Rene
Thank you for your detailed reply.
1. It seems the Adiabatic surface temperature should be 1600 K by default.
However this alone is not enough to solve the convergence of the iterative
Stokes solver.
2. The convergence in 2D could not be achieved also, but
3. a simple material model with Thermal viscosity exponent=10 worked quite
well, therefore, a resolution is well-defined after all, is it?
4. However, I run a test setting the global refinement in the 3D model to 5
and the adaptive refinement to 0 and it seems nothing happened (the job is
done after ~30 sec - there is no error message), this is a log file:
> Number of active cells: 3145728 (on 6 levels)
> Number of degrees of freedom: 104645770 (76088070+3195010+25362690)
>
5. If I set the temperature dependence to 0 as you explained and use a
constant radial viscosity profile test-radial-visc.txt (inside
aspect/data/material-model/steinberger/test-steinberger-compressible/) then
the code works for a while, to be precise 13 timesteps,
> *** Timestep 13: t=343515 years
> Solving temperature system... 19 iterations.
> Rebuilding Stokes preconditioner...
> Solving Stokes system... 30+15 iterations.
>
> Postprocessing:
> RMS, max velocity: 0.583 m/year, 3.54 m/year
> Temperature min/avg/max: 300 K, 1934 K, 3565 K
>
Heat fluxes through boundary parts: -2.756e+13 W, 2.332e+13 W
>
and after that I have received the following error message:
> 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)
>
So, help! No idea how to move forward.
Many thanks,
Petar
*Rene Gassmoeller rengas at gfz-potsdam.de
> <aspect-devel%40geodynamics.org?Subject=Re%3A%20%5Baspect-devel%5D%20problem%20with%20ASPECT%20-%20the%20iterative%20Stokes%0A%20solver%20did%20not%20converge&In-Reply-To=%3C53D5EB69.30809%40gfz-potsdam.de%3E>*
>
*Sun Jul 27 23:19:21 PDT 2014*
>
Hi Petar,
> from a first glance the parameters you used for your model look good,
> but there is one thing you should test. In your parameter file you did
> not set the Adiabatic surface temperature, because it is not needed for
> the simple material model, and it defaults to 0 (@Wolfgang: We should
> maybe change this to a reasonable value like 1600? Many of the more
> complex plugins rely on a good adiabatic profile). The Steinberger
> material model, and also your harmonic perturbation initial condition
> rely on the initially computed adiabatic profile to compute their
> properties, therefore this might mess up you calculation. I would guess
> this is already the problem.
>
> However there are a few other things that you might try to find the
> reason for the convergence problems if the above did not help. First you
> could test the convergence in 2D, in your model setup that is as simple
> as setting Dimension = 2. And you could try a higher resolution in 2D.
> Both options should show significantly better convergence, so you have
> at least a starting point.
>
> Then you could test a temperature dependency in the simple material
> model (e.g. set Thermal viscosity exponent to something like 10). If
> this turns out to be a problem then your resolution might be too low to
> resolve the viscosity changes you are prescribing.
>
> If it turns out to be a resolution issue, try setting the global
> refinement in the 3D model to 5 and the adaptive refinement to 0. Aspect
> will still coarsen and adaptively refine again later on, just the
> initial convergence should be much better.
>
> You mentioned that you tested a constant viscosity profile with the
> Steinberger material model, but in the parameter file it looks like you
> only modified the radial dependence? Did you also set the temperature
> dependence to 0? You could do that by setting 'Lateral viscosity file
> name' to our test file in
> data/material-model/steinberger/test-steinberger-compressible/test-viscosity-prefactor.txt.
> With a constant radial and lateral viscosity the convergence should be
> extremely fast.
>
> Let us know if you have any further questions.
>
> In fact I have a question for you. We are constantly looking to improve
> the available options in Aspect and include new models. Could you ask
> Alessandro, whether he would be willing to share the viscosity profile
> you used with the general Aspect users? In that case we could include it
> in the official version as an alternative to the existing one by
> Steinberger & Calderwood.
>
> Best,
> Rene
>
>
On Fri, Jul 25, 2014 at 6:22 PM, Petar Glisovic <pglisovic at gmail.com> wrote:
> 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
>
--
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
@gmail.com & glisovic.petar at courrier.uqam.ca* | phone: *1-514-987-3000
#3592 & #4600* | fax: *1-514-987-3635
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.geodynamics.org/pipermail/aspect-devel/attachments/20140804/874807c6/attachment-0001.html>
More information about the Aspect-devel
mailing list