Geoffrey and Stephen, Identifying halos with only a single particle by itself makes a pretty good argument that pHOP should apply a "minimum number of particles" setting. If you are interested in the requirements for resolving a halo with Enzo (which I believe is the source of the data you are using) you should see the discussion on yt-users between Brian O'Shea and Michele Trenti, and the papers cited therein, for more information. I would humbly suggest that you rethink what you are doing if you are trying to find the ellipsoidal extent of a four particle "halo." Come on, really? Even if we were able to get past the requirement that the word "halo" has some kind of semantic meaning when discussed in the context of a single particle, just from the perspective of creating Python objects for each Halo this can cause a gigantic problem. -Matt On Fri, Oct 28, 2011 at 2:48 PM, Stephen Skory <s@skory.us> wrote:
Geoffrey,
I was under the impression from our previous talk that there's a lowest number threshold that pHOP requires to form a halo, I thought the number was 10 particles at least. Am I just remembering things wrong? It has been a couple of years...
My memory is a bit faded, too, but I think I remember the story. Regular HOP does restrict halos to some particle count, but I think that was turned off in pHOP in favor of letting the user filter the answers on their own. In this sense, I think you've come to a satisfactory fix. Do you agree?
-- Stephen Skory s@skory.us http://stephenskory.com/ 510.621.3687 (google voice) _______________________________________________ Yt-dev mailing list Yt-dev@lists.spacepope.org http://lists.spacepope.org/listinfo.cgi/yt-dev-spacepope.org