Selecting halos with specific mass/position

[milanq14]

Hey!

I am trying to select only certain halos in my simulation, which satisfy certain conditions like having a mass greater than some M or being at a distance less than certain distance d, something like:

h=s.halos()
satellites = h[(h['pos'][0][0]**2+h['pos'][0][1]**2+h['pos'][0][2]2<Rvir2) ]

Reading the tutorial I am not able to find a way to do this with pynbody... anyone wanting to help me with this?

Thanks!