Statepoint file format version

User Support
1

Hi everyone,

I have problem with OpenMC 0.90 (the latest version). I had it installed a month ago and it worked great. Now I tried to install it on a different computer, but I get an error when trying to access the statepoint files. The error is the statepoint file format version. If i try to open the statepoint file from the simulation, I get the output:

Traceback (most recent call last):
File “trial.py”, line 3, in
sp = openmc.StatePoint(’/home/sharef8/juan/Trabajo reaktor 2017/Tutorial-notebook/statepoint.2.h5’)
File “/usr/local/lib/python2.7/dist-packages/openmc-0.9.0-py2.7.egg/openmc/statepoint.py”, line 122, in init
cv.check_filetype_version(self._f, ‘statepoint’, _VERSION_STATEPOINT)
File “/usr/local/lib/python2.7/dist-packages/openmc-0.9.0-py2.7.egg/openmc/checkvalue.py”, line 270, in check_filetype_version
.format(this_filetype, ‘.’.join(this_version),
TypeError: sequence item 0: expected string, numpy.int32 found

The reason for this error is the following: (I added the print statements to checkvalue.py)

print(this_filetype, this_version)
print(expected_type, expected_version)

(u’statepoint’, array([16, 0], dtype=int32))
(‘statepoint’, 17)

It detects the statepoint file format as 16.0, when the expected file format is 17.0. If I try to override the expected file format to 16.0, the statepoint file is read, but I get other errors (it doesn’t read any of the tally filters,…). The Input files for the simulation have been tested on my first laptop with the OpenMC 0.9 (that I installed in July) and they raise no errors.

Has anything been changed in OpenMC since July, so that the statepoint file fromat version changes, or is there a problem with my installation of OpenMC?

2

Hi Juan,

We have been working to improve the performance of tallies, and one part of that was changing how filters are implemented in the Fortran side of the code. That change did have the side effect of changing the statepoint file format, so if you are on the develop branch, the Python API won’t be able to parse statepoints that were generated with the last stable release (0.9.0) of OpenMC. If you generate statepoints using the develop branch, however, those should work fine. Let me know if I can help further.

Best,
Paul