Hey All,

I'm having some trouble smoothing particle velocities onto a uniform (arbitrary_grid) grid.  The basic idea is that I create an arbitrary grid, then want to access the particle quantities smoothed onto that grid.  Some are relatively easy, like:

mass =  obj[('deposit','PartType0_mass')].in_units('Msun')


and for others, where deposited fields don't already exist, I can create those fields and it all works well:

ds.add_deposited_particle_field(('PartType0', 'Temperature'),'sum')
temp = obj[('deposit', 'PartType0_sum_Temperature')]

but when either trying to access a deposited particle field, or creating one with the velocities, errors are abound.  I'm sure I'm just doing something foolish, but could use a little nudge in the right direction.  I created a self-contained script using the gadget zoom data set on the yt datsets to show the problem, with two different error messages pastebinned (links in the script) here:

http://paste.yt-project.org/show/6352/

any help would be greatly appreciated!

thanks,
desika