[CIG-SHORT] two pylith problems

[Brad Aagaard]

Chris-

The two-cell examples don't use the asm preconditioner for a reason- it isn't 
appropriate for those problems because they are not fully constrained (in 
many cases rotations are possible). Try it on examples/3d/hex8 or 
examples/3d/tet4. You may not see much difference on these small problems, 
but we found a significant reduction in the number of iterations required for 
convergence for the strike-slip benchmark.

Brad


On Wednesday 05 December 2007, Christopher DiCaprio wrote:
> I've encountered two problems in running the new pylith linux binary.
>
> Following the suggestion to use the asm preconditioner I tried it out
> on one of the included examples.  When I run examples/twocells/
> twotet4/axialdisp.cfg I get different answers depending on the
> preconditioner.  Here are the relevant parts of the vtk files:
>
> pc_type = asm
> -----------------------------------------------------------------
> VECTORS displacements_t0.000000 double
> -0.01 0 0
> 2.6718e-19 0.0025 -0.00840477
> 2.6718e-19 -0.00840477 -0.0025
> 2.6718e-19 -0.0025 0.00840477
> 0.01 0 0
>
> pc_type = jacobi
> -----------------------------------------------------------------
> VECTORS displacements_t0.000000 double
> -0.01 0 0
> -2.86102e-19 0.0025 1.70977e-17
> 3.57628e-19 2.91236e-18 -0.0025
> -2.86102e-19 -0.0025 1.34636e-17
> 0.01 0 0
>
> Note the difference in the y-displacement.
>
> When I run examples/twocells/twotet4/displacement.cfg I run into
> petsc errors when using pc_type = asm.  See the attached file
> dislocation.asm.log.  There are no errors when using the jacobi
> preconditioner.
>
>
>
> My other problem concerns a large mesh.  I reported a problem using
> this mesh to the list before and Brad thought it was a bug in the
>
> cohesive cells.  With the new binary I get a different error:
>   >> /home/buildbot/install/x86_linux_single_nosched_binbot/lib/
>
> python2.5/site-packages/pylith/meshio/MeshIO.py:45:read
>   -- meshiolagrit(info)
>   -- Reading finite-element mesh
> Traceback (most recent call last):
>    File "<string>", line 1, in <module>
>    File "/home/buildbot/install/x86_linux_single_nosched_binbot/lib/
> python2.5/site-packages/pythia-0.8.1.4-py2.5.egg/mpi/__init__.py",
> line 42, in mpistart
>    File "/home/buildbot/install/x86_linux_single_nosched_binbot/lib/
> python2.5/site-packages/pythia-0.8.1.4-py2.5.egg/pyre/applications/
> __init__.py", line 41, in start
>    File "/home/buildbot/install/x86_linux_single_nosched_binbot/lib/
> python2.5/site-packages/pythia-0.8.1.4-py2.5.egg/pyre/applications/
> Shell.py", line 139, in run
>    File "/home/buildbot/install/x86_linux_single_nosched_binbot/lib/
> python2.5/site-packages/pythia-0.8.1.4-py2.5.egg/pyre/applications/
> SuperScript.py", line 49, in execute
>    File "/home/buildbot/install/x86_linux_single_nosched_binbot/lib/
> python2.5/site-packages/pythia-0.8.1.4-py2.5.egg/pyre/applications/
> SuperScript.py", line 58, in main
>    File "/home/buildbot/install/x86_linux_single_nosched_binbot/lib/
> python2.5/site-packages/pythia-0.8.1.4-py2.5.egg/pyre/applications/
> SuperScript.py", line 62, in runSubscript
>    File "/home/buildbot/install/x86_linux_single_nosched_binbot/lib/
> python2.5/site-packages/pythia-0.8.1.4-py2.5.egg/pyre/applications/
> Application.py", line 42, in run
>    File "/home/buildbot/install/x86_linux_single_nosched_binbot/lib/
> python2.5/site-packages/pythia-0.8.1.4-py2.5.egg/pyre/applications/
> Shell.py", line 139, in run
>    File "/home/buildbot/install/x86_linux_single_nosched_binbot/lib/
> python2.5/site-packages/pythia-0.8.1.4-py2.5.egg/mpi/Application.py",
> line 118, in _onComputeNodes
>    File "/home/buildbot/install/x86_linux_single_nosched_binbot/lib/
> python2.5/site-packages/pythia-0.8.1.4-py2.5.egg/mpi/Application.py",
> line 124, in onComputeNodes
>    File "/home/buildbot/install/x86_linux_single_nosched_binbot/lib/
> python2.5/site-packages/pylith/PyLithApp.py", line 90, in main
>    File "/home/buildbot/install/x86_linux_single_nosched_binbot/lib/
> python2.5/site-packages/pylith/topology/MeshImporter.py", line 81, in
> create
>    File "/home/buildbot/install/x86_linux_single_nosched_binbot/lib/
> python2.5/site-packages/pylith/topology/MeshGenerator.py", line 96,
> in _adjustTopology
>    File "/home/buildbot/install/x86_linux_single_nosched_binbot/lib/
> python2.5/site-packages/pylith/faults/Fault.py", line 132, in
> adjustTopology
>    File "faults.pyx", line 108, in faults.Fault.adjustTopology
> RuntimeError: Caught unknown C++ exception.
> --pyre-start: mpiexec: exit 1
> /home/dicaprio/local/pylith-1.0.2-linux-i686/bin/pylith: /home/
> dicaprio/local/pylith-1.0.2-linux-i686/bin/nemesis: exit 1
>
>
>
> Is this a problem with my mesh or a bug?
>
> Thanks,
> Chris