[yt-users] Problem with Rockstar in yt

[Brian O'Shea]

Dear yt-users,

I'm trying to use the Rockstar halo finder within yt, and am encountering
some odd problems.  I'm using the main development tree (
https://bitbucket.org/yt_analysis/yt) with changeset f936432ed45d, and
attempting to use Rockstar to find halos on a small server running Ubuntu
12.04.  When I call this script:

---- file test_rockstar.py ----

from yt.mods import *
from yt.analysis_modules.halo_finding.rockstar.api import RockstarHaloFinder

pf = load("DD0057/data0057")
rh = RockstarHaloFinder(pf)

---

using the command line sequence "mpirun -np 2 python ./test_rockstar.py
--parallel", I seem to be getting a seg fault (as can be seen at
http://paste.yt-project.org/show/3745/).  However, if I use a single
processor (with "mpirun -np 1 python ./test_rockstar.py --parallel"), I get
a very different error:

Traceback (most recent call last):
  File "./test_rockstar.py", line 6, in <module>
    rh = RockstarHaloFinder(pf)
  File
"/data/bwoshea/galparttest/yt-x86_64/src/yt-hg/yt/analysis_modules/halo_finding/rockstar/rockstar.py",
line 230, in __init__
    self.pool, self.workgroup = self.runner.setup_pool()
  File
"/data/bwoshea/galparttest/yt-x86_64/src/yt-hg/yt/analysis_modules/halo_finding/rockstar/rockstar.py",
line 112, in setup_pool
    (self.num_writers, "writers") ]
  File
"/data/bwoshea/galparttest/yt-x86_64/src/yt-hg/yt/utilities/parallel_tools/parallel_analysis_interface.py",
line 335, in from_sizes
    pool.add_workgroup(size, name = name)
  File
"/data/bwoshea/galparttest/yt-x86_64/src/yt-hg/yt/utilities/parallel_tools/parallel_analysis_interface.py",
line 303, in add_workgroup
    group = self.comm.comm.Get_group().Incl(ranks)
AttributeError: 'NoneType' object has no attribute 'Get_group'

I'm puzzled about the error, since I can use other parallel yt scripts
without any problems (a 4-processor script making projections works just
fine).  This machine doesn't have infiniband (as warned about at
http://yt-project.org/doc/analysis_modules/running_halofinder.html#rockstar-halo-finding),
and both FOF and Hop find several hundred halos with my dataset.  I'd just
use another halo finder, but I'm trying to do something that requires
Rockstar to be run inline with Enzo, so I'm stuck with it...

Does anybody have any idea what might be going on?

Thanks!

Brian
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.spacepope.org/pipermail/yt-users-spacepope.org/attachments/20130804/79eba921/attachment.htm>