Hi all,

I'm trying to use FixedResolutionBuffer to generate 2d projections following the example in the docs (http://yt-project.org/doc/analyzing/generating_processed_data.html)

from yt.mods import *
pf = load("DD0000/test_disk_0000")
projden = pf.h.proj(0,'Density',data_source=pf.h.all_data(),center=[0.5,0.5,0.5])
frb = FixedResolutionBuffer(projden,(0,0,1,1),(512,512))
print frb['Density']
------> print(frb['Density'])
yt : [INFO     ] 2011-09-02 00:03:10,273 Making a fixed resolution buffer of 512 by 512
[[ nan  nan  nan ...,  nan  nan  nan]
 [ nan  nan  nan ...,  nan  nan  nan]
 [ nan  nan  nan ...,  nan  nan  nan]
 ..., 
 [ nan  nan  nan ...,  nan  nan  nan]
 [ nan  nan  nan ...,  nan  nan  nan]
 [ nan  nan  nan ...,  nan  nan  nan]]

Is there a problem with how I'm creating the buffer?  I'm pretty sure the way this is done in the docs on the page I linked is incorrect, since I get an error when I do when I try to say

sl = pf.h.proj(0,0.5)

Thanks for your help,
Nathan