Hi, (this question refers to code in the trunk version of yt, not the 1.0 version.) I am trying to calculate the virial mass for about 70,000 haloes in a fairly large cosmology simulation. Out of those, I'm only getting about 61,000 lines in VirialQuantities.out, and of those, 20,000 are actually nans. So out of 70,000 haloes from HOP, I have only about 40,000 virial masses. I don't imagine many people have run the HaloProfiler on a dataset this large, but is a 40% error rate typical? Can you suggest any strategies to minimize the number of nans and missing haloes? Is it likely I'm doing something wrong (which is a strong possibility)? Thanks! _______________________________________________________ sskory@physics.ucsd.edu o__ Stephen Skory http://physics.ucsd.edu/~sskory/ _.>/ _Graduate Student ________________________________(_)_\(_)_______________