get halo's particle sample when only partial snapshot data are available?
Sihan Yuan
10 Aug '21
Hi,
I am trying to get the particle sets of all halos within a specific chunk. This came about because I want to run a test on a set of halos and their particles, but I do not want to download the whole snapshot. So how do I go about selecting only halos that correspond to a specific chunk, and then getting their particles?
Thanks!
Dylan Nelson
10 Aug '21
Note that you can download particle cutouts (see e.g. Task 4) for a specific halo, which might be easiest.
Otherwise, if you have downloaded a chunk, you can check the offsets. If the offset for a halo starts within the chunk, and offset+length finishes within the chunk, then you can find all its particles (of a given type) there.
Hi,
I am trying to get the particle sets of all halos within a specific chunk. This came about because I want to run a test on a set of halos and their particles, but I do not want to download the whole snapshot. So how do I go about selecting only halos that correspond to a specific chunk, and then getting their particles?
Thanks!
Note that you can download particle cutouts (see e.g. Task 4) for a specific halo, which might be easiest.
Otherwise, if you have downloaded a chunk, you can check the offsets. If the
offset
for a halo starts within the chunk, andoffset+length
finishes within the chunk, then you can find all its particles (of a given type) there.