[Yt-dev] ParticleIO patch for review

[Matthew Turk]

Hi everyone,

Stephen's gotten a lot of great stuff stuck into the SVN trunk, and
I'm trying to make sure that the particle support is there for him.
The new ParticleIO is getting close to being "ready for primetime",
but I'm going to need some help testing it.  I've uploaded a patch:

http://paste.enzotools.org/show/288/

What this will do is co-opt the particle IO from a standard dict-like
access of an AMR3DData instance and, if it's a particle type, pass it
through the ParticleIO(.py) object.  Right now this will only affect
Regions -- everything else will simply operate as normal.  (i.e.,
spheres will just get passed on through.)  As a note, the new
ParticleIO is set up to do two-passes through a region, first counting
the particles that will end up in the object and then reading them.
This speeds up IO considerably, as it reduces the number of array
creation operations to a minimum.

(My sample script for testing is here, but I'd prefer if you could
test in a real-world application...
http://paste.enzotools.org/show/289/ )

If possible, could a few of you test this out, and let me know if this
patch interferes with any normal behavior?  I'm running my own tests
here and it's looking *okay*, but it should get tested in the field a
bit before being committed.  After that, I'll add the necessary
methods for spheres, and then the ParticleIO should be mostly handled
by the new mechanism.

Thanks for any ideas and testing!

-Matt