SubhaloFlag field in groupcat

Magnan Nathan
  • 1
  • 23 Apr '20

Hello Dylan,

I am playing with Illustris-1 data, but staying quite close to the Python tutorial (https://www.tng-project.org/data/docs/scripts/) for now.

For that, I downloaded the group catalog for picture 135 of Illustris 1 thanks to the command line given :

$ wget -nd -nc -nv -e robots=off -l 1 -r -A hdf5 --content-disposition --header="API-Key: insert API-key here" "http://www.tng-project.org/api/Illustris-1/files/groupcat-135/?format=api"

And I downlaoded the illustris_python library from github.

I found in the specs (https://www.tng-project.org/data/docs/specifications/#sec2b) that the field 'SubhaloFlag' should be used when counting galaxies. However when I try to use it with the following code :

basePath = './Illustris-3/output/'
fields = ['SubhaloMass', 'SubhaloFlag']
subhalos = il.groupcat.loadSubhalos(basePath,135,fields=fields)

I get the following error :

Group catalog does not have requested field [SubhaloFlag]!

Do you have any idea what I did wrong ?
If it may help, I think that I get this error with any field that is blue in the specs webpage, but it works perfectly with any field that is green.

Thank you !

Dylan Nelson
  • 23 Apr '20

Hi Magnan,

The SubhaloFlag is new and only exists for TNG simulations. I would suggest you simply switch from Illustris-3 to TNG100-3 in general.

Magnan Nathan
  • 23 Apr '20

Oh ok that's why,
Thank you very much !

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