[SciPy-user] Eigenvalues of the Floquet matrix

Rob Clewley rob.clewley@gmail....
Wed Mar 18 10:29:54 CDT 2009


Hi Nils,

On Wed, Mar 18, 2009 at 2:44 AM, Nils Wagner
<nwagner@iam.uni-stuttgart.de> wrote:
> Rob,
>
> I switched to python2.5
> python -i seyranian-PyDSTool.py
> -3.41421356237
> /home/nwagner/svn/PyDSTool/integrator/radau5.f: In

[SNIP]

> Segmentation fault
>


This is getting a bit out of my depth, and I don't normally see
segfault problems with these integrators, but I have a couple of
suggestions.

Does interp_dopri_test run or do you also get a segfault? Radau is a
fortran-based integrator and that can bring extra problems. The bug
report you submitted on SF indicates that you ran that test with
Python 2.6 not 2.5, although since you got a segfault there too it's
possible that it's not a 2.5 vs. 2.6 issue after all. Could it be
something about your 64 bit platform? Are the standard libraries all
slightly different somehow? The segfault is coming from
lib64/libpython2.5.so. What version of gcc are you running? Based on
past experience I recommend 3.1 but 3.3 may also work. I will try to
do some research about getting DLLs working via SWIG on 64 bit
platforms to see if there are known problems.

>
> Below is a backtrace
>
> gdb python
> This GDB was configured as "x86_64-suse-linux"...(no
> debugging symbols found)
> Using host libthread_db library
> "/lib64/libthread_db.so.1".
>
[SNIP]
> (gdb) run seyranian-PyDSTool.py
> Starting program: /usr/bin/python seyranian-PyDSTool.py
[SNIP]
> Program received signal SIGSEGV, Segmentation fault.
> [Switching to Thread 47382264377744 (LWP 10240)]
> 0x00002b180a23065b in PyEval_EvalFrameEx () from
> /usr/lib64/libpython2.5.so.1.0
> (gdb) bt
> #0  0x00002b180a23065b in PyEval_EvalFrameEx () from
> /usr/lib64/libpython2.5.so.1.0

Is it possible to configure gdb to include debugging symbols? I don't
know what that entails off the top of my head, but it would mean we'd
get a much more detailed report.

-Rob


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