[Yt-dev] yt-hop configuration improvements?

[Matthew Turk]

Hi Stephen,

> I actually haven't gotten the plot yet that Brian made due to my HaloProfiler problem (which I'm about to start working on). I have got his list of haloes reproduced. The plot I made earlier was with a threshold=160.0, and Brian ran at 80.0. He also ran with a lower minimum group size in regroup (2 versus 20), which is something that is currently hard coded in yt-hop. So the lower threshold and the lower minimum group size is what I needed.

The hop website says two things of note here:

"""
-mingroup  int
    Only groups with this many particles or more will be outputted. Default: 10

Remember that HOP is biased against finding groups smaller than N_dens
or N_hop; hence, setting -mingroup to be tiny is usually pointless.
"""

I'll make this a parameter, but I am going to leave it at -1 for
default, which sets it to 10.  This is what it's been doing...  I've
also set the dsaddle by default to be what Greg suggested,
2.5*threshold.

> So in summary, I see what you're saying. I'd then add at minimum, the minimum group size, and -dsaddle.

Done, changeset is on bitbucket:

http://bitbucket.org/MatthewTurk/yt/changeset/4f9a83beabb2/

Strictly speaking I don't need to set self.mingroupsize and
self.dsaddle in the HaloFinder, but that's not a big deal.
HopOutput.py doesn't need these changes because they're optional
arguments.

-Matt