Hey everyone, The following error pertains to the yt branch of the hg repo. I'm getting a particle io error when using the various yt halo finders in parallel. It doesn't appear to have anything to do with the halo finders, but I don't know what else uses ParticleIO.py. This only happens when running in parallel. P000 yt INFO 2009-11-27 15:16:59,775 Getting ParticleMassMsun using ParticleIO Setting period equal to 1.000000 Setting period equal to 1.000000 Setting period equal to 1.000000 Traceback (most recent call last): File "do_hop.py", line 5, in <module> h = FOFHaloFinder(pf) File "/Users/britton/Documents/work/yt-hg/yt/lagos/HaloFinding.py", line 1024, in __init__ self._parse_halolist(1.) File "/Users/britton/Documents/work/yt-hg/yt/lagos/HaloFinding.py", line 747, in _parse_halolist this_max_dens = halo.maximum_density_location() File "/Users/britton/Documents/work/yt-hg/yt/lagos/ParallelTools.py", line 130, in single_proc_results return func(self, *args, **kwargs) File "/Users/britton/Documents/work/yt-hg/yt/lagos/HaloFinding.py", line 322, in maximum_density_location return self.center_of_mass() File "/Users/britton/Documents/work/yt-hg/yt/lagos/ParallelTools.py", line 130, in single_proc_results return func(self, *args, **kwargs) File "/Users/britton/Documents/work/yt-hg/yt/lagos/HaloFinding.py", line 306, in center_of_mass pm = self["ParticleMassMsun"] File "/Users/britton/Documents/work/yt-hg/yt/lagos/ParallelTools.py", line 130, in single_proc_results return func(self, *args, **kwargs) File "/Users/britton/Documents/work/yt-hg/yt/lagos/HaloFinding.py", line 136, in __getitem__ return self.data.particles[key][self.indices] File "/Users/britton/Documents/work/yt-hg/yt/lagos/ParticleIO.py", line 46, in __getitem__ self.get_data(key) File "/Users/britton/Documents/work/yt-hg/yt/lagos/ParticleIO.py", line 104, in get_data if len(to_add) != 1: raise KeyError KeyError I checked the contents of to_add, and it was a list with two items (hence the exception): ['particle_mass', 'particle_mass'] I was able to get around this by removing non-unique entries in to_add, but I don't think that really fixes the underlying problem. Anyone have any ideas? Regards, Britton