Hi Sam, Here is how I am using it right now... hp.add_halo_filter(HP.VirialFilter,must_be_virialized=True, overdensity_field='ActualOverdensity', virial_overdensity=200, virial_filters=[['TotalMassMsun','>=','5e11']], virial_quantities=['TotalMassMsun','RadiusMpc']) hp.make_profiles(filename="VirialHaloes.out") And i get 500. Do you think it has something to do with the grid spacing (for 512 ^3 grid in 200 Box, it is 390 Kpc) HaloProfiler may be skipping small halos completely since they are smaller than 390 Kpc. Shankar -----Original Message----- From: yt-users-bounces@lists.spacepope.org on behalf of Sam Skillman Sent: Sun 2/28/2010 12:34 PM To: Discussion of the yt analysis package Subject: Re: [yt-users] Dealing with HOP groups Hi Shankar, Do you have a line that looks like: hp.add_halo_filter(HP.VirialFilter,must_be_virialized=True, overdensity_field='ActualOverdensity', virial_overdensity=200, virial_filters=[['TotalMassMsun','>=','1e14']], virial_quantities=['TotalMassMsun','RadiusMpc']) If so, please post it. The number of halos > 10^14 Msun is fairly close to 500 in a 200 Mpc box. If you want the halo profiler to use all halos, set virial_filters=[['TotalMassMsun','>=','1e14']] accordingly. Sam On Sun, Feb 28, 2010 at 11:08 AM, Agarwal, Shankar <sagarwal@ku.edu> wrote:
Hi Stephen,
I read http://lists.spacepope.org/pipermail/yt-users-spacepope.org/2009-March/00011...
Do you remember the cosmology parameters for your run: particles, grid, box, refinement, AMR ON or OFF ?
I have run a 200 Mpc/h box, 512^3 particle, 512^3 grid, AMR-OFF simulation and I get about 30,000 halos using HOP. When I try to finding virial halos, I get only 500. I may have to increase the grid to 1024^3.
Let me know how you got 40,000 virial halos.
Thanks Shankar _______________________________________________ yt-users mailing list yt-users@lists.spacepope.org http://lists.spacepope.org/listinfo.cgi/yt-users-spacepope.org
-- Samuel W. Skillman DOE Computational Science Graduate Fellow Center for Astrophysics and Space Astronomy University of Colorado at Boulder samuel.skillman[at]colorado.edu