Hi Stephen, Thank you very much for your reply! I apologize if I was not clear in my mail. I am not interested in using fastBuildMerge.py, I am only looking for a list of particles IDs associated to each halo. I have my own code to track mergers. If you can point me to where this information is saved by yt-hop it would be very helpful. Thanks again, Michele Michele Trenti Center for Astrophysics and Space Astronomy University of Colorado 389 UCB Phone: +1 303-492-8490 Boulder, Colorado 80309-0389 Fax: +1 303-492-7178 USA E-mail: michele.trenti@colorado.edu "It often happens that a player carries out a deep and complicated calculation, but fails to spot something elementary right at the first move." -- Chess Grandmaster Alexander Kotov On Wed, 13 May 2009, Stephen Skory wrote:
Hi Michele,
I am a new user of yt and I trying to run the yt-hop Halo Finder to build a merger history of halos.
Yes, it is possible. You need to be running out of trunk.
The first step is to make a copy of 'examples/fastBuildMerge.py' to your favorite location. This is a Python script that builds a Python script that will drive yt. Got it? Good.
In your copy of fastBuildMerge.py, edit the values at the top. It's heavily commented, so I hope you will be able to understand what each does. Reply to the list if you need help understanding them.
You'll want to run HOP on the last (z=0?) timestep by hand to find the halo(es) you wish to track back in time, but it sounds like you've already done that.
Run Python on this script, which outputs the actual script that drives yt. Run the new script and you should get the merger tree.
One final note: as I responded to your email, I noticed I had a typo in the trunk version of fastBuildMerge, which I've updated in r1305, so you should 'svn up' before starting.
Good luck! _______________________________________________________ sskory@physics.ucsd.edu o__ Stephen Skory http://physics.ucsd.edu/~sskory/ _.>/ _Graduate Student ________________________________(_)_\(_)_______________ _______________________________________________ yt-users mailing list yt-users@lists.spacepope.org http://lists.spacepope.org/listinfo.cgi/yt-users-spacepope.org