[Yt-dev] yt fof question

Hi everyone, I think this question is mainly for Stephen and possibly John, if he's on this list. I was trying to make a direct comparison between the halos found with yt FOF and with John Wise's FOF for the same simulation. The mass functions definitely look the same, but the particle membership for any given halo is totally different. I'm sure this is just a matter of the particle indexing. Does yt FOF use the particle IDs from enzo, or some different system? Any ideas for how I might correct this issue would be greatly appreciated. Thanks, Britton