Is there a way to run the halo finder on part of the simulation volume? For example, I have a box 256 Mpc on a side but I only want to find halos inside a smaller box, say 20 Mpc on a side.
Unfortunately, this is not currently possible in yt. However, it should be possible if the right modifications are done. Something along these lines is how HOP/FOF are parallelized, so it should be translateable to your problem. I am not making promises that I will do this, but that it is possible. I'll think about it.
However, I wonder why you only want halos in a small region? Do you have a nested simulation? Does it seem like the halo finding is taking too long? Are you looking for substructure? Depending on the answers to these questions, the modifications discussed above may not be required.
_______________________________________________________ email@example.com o__ Stephen Skory http://physics.ucsd.edu/~sskory/ _.>/ _Graduate Student ________________________________(_)_\(_)_______________