Hi John,

I'm not sure why Electron_Density is in memory, either, unless it pulled it from the .yt file like you suggested. I think this fix is fine -- either here or inside the _mpi_catdict routine should be just great.

Thanks for catching this!

-Matt

On Mon, Mar 29, 2010 at 9:57 AM, John Wise jwise@astro.princeton.edu wrote:

Hi,

I think I found a little bug when calling get_data() in parallel jobs.  I was trying to make basic slices of Density, Temperature, and Electron_Fraction.  When it gets to the Electron_Fraction slice, it already had the data in memory, so temp_data == {}.  I'm not sure why it was already in memory, I hadn't accessed Electron_Density yet.  Perhaps it was loaded from the .yt file?  Then the routine tries to accumulate temp_data with _mpi_catdict(), and this is where things go wrong because temp_data is empty!

An if-statement before this call avoided this bug,

diff -r c248cd4313a8 yt/lagos/BaseDataTypes.py --- a/yt/lagos/BaseDataTypes.py Sun Mar 28 23:31:52 2010 -0700 +++ b/yt/lagos/BaseDataTypes.py Mon Mar 29 12:47:20 2010 -0400 @@ -593,7 +593,8 @@             # Now the next field can use this field             self[field] = temp_data[field]         # We finalize

• temp_data = self._mpi_catdict(temp_data)

• if temp_data != {}:
• temp_data = self._mpi_catdict(temp_data)

# And set, for the next group         for field in temp_data.keys():             self[field] = temp_data[field]

I just wanted to make sure that this is the right thing to do before committing.

John _______________________________________________ Yt-dev mailing list Yt-dev@lists.spacepope.org http://lists.spacepope.org/listinfo.cgi/yt-dev-spacepope.org