I was trying to get the position and mass information for the dark matter (and stellar) particles in an Enzo simulation.  I have tried a couple of different ways and I was curious about the units on the following method. In this case I am presumably accessing the dark matter particles (particle_type = 1)

from yt.mods import *
pf = load("DD0252/DD0252")
array = pf.h.find_particles_by_type(ptype=1, max_num=3)
print "(%.5f, %.5f, %.5f) = %f\n" %(array['particle_position_x'][0], array['particle_position_y'][0], array['particle_position_z'][0], array['particle_mass'][0])

This returns (0.01055, 0.01873, 0.00224) = 0.835448. What are the mass units on the 0.835448?  I don't think that they are cgs, and there doesn't appear to be a conversion factor available via pf[' * '].  If I continue and enter 

print pf.field_info['Density'].get_units()
print pf.field_info['particle_mass'].get_units()

The 'Density' line returns \rm{g}/\rm{cm}^3, but the 'particle_mass' line returns nothing. So I can't get the units from here. I can, however, access the same particle (or at least a particle at the same location) by using

from yt.mods import *
pf = load("DD0252/DD0252")
dd = pf.h.all_data()
print "(%f %f %f) =  %f Msun, ptype= %i\n"%(dd["particle_position_x"][0], dd["particle_pos    ition_y"][0], dd["particle_position_z"][0], dd["ParticleMassMsun"][0],dd["particle_type"][0])

Which returns (0.010554 0.018727 0.002239) =  82255596.670652 Msun, ptype= 1

This seems to give reasonable values. Both methods should be equivalent ways of to access the particle (both stellar and dark matter) data, correct?  So how do I get my units in solar masses when using pf.h.find_particles_by_type()?  Thanks for your time!