Public Data Access Overview / Discussion Forum

Hi Dylan,

Trying to load subhalo data using the API:

snap = 99
subfields = ['SubhaloFlag', 'SubhaloBHMass']
subhalos = ill.groupcat.loadSubhalos(basePath, snap, fields=subfields)

Exception: Group catalog does not have requested field [SubhaloFlag]! (which are listed in the Data Spec)...

Question: what are the admissable fields that can be used with the ill.groupcat.loadSubhalos function of the API?

What is basePath in your example?

Thanks Dylan,

My basepath changes locally depending on whether I am on Linux/Windows:

# Config basepath accordingly (Linux vs Windows)
basePath = 'D:/IllustrisData/TNG100-1-Dark/output'
#basePath = '/home/andre/Illustris_Data/TNG100-1-Dark/output'

But I dont think that is the issue, since getting the halo data is working:

snap = 99
fields = ['Group_M_Crit200', 'GroupFirstSub']
halos = ill.groupcat.loadHalos(basePath, snap, fields=fields)
print("halos['Group_M_Crit200'] = ", halos['Group_M_Crit200'].shape)
print("halos['GroupFirstSub'] = ", halos['GroupFirstSub'])

The issue happens when I try the corresponding sub-halo data:

subfields = ['SubhaloFlag', 'SubhaloMass']
subhalos = ill.groupcat.loadSubhalos(basePath, snap, fields=subfields)

This is for Illustris-1-Dark locally downloaded (snap-99).

The SubhaloFlag field only exists for baryonic runs, not dark matter only runs, where it wouldn't make sense.

I have added this clarification to the documentation, thanks for the note.

Thanks Dylan.