[yt-users] Best way to count particles?

[Stephen Skory]

Hi Matt,

> What's the best way to get the number of particles of a particular
> type from a data object?
>
> i.e., the derived quantity way of doing:
>
> (dd["particle_type"] == something).sum()

This should probably work, what do you think Matt?

from yt.mods import *

def _pcount(field, data):
    return (data["particle_type"] == 0).sum()

add_field("pcount", function=_pcount, particle_type=True)

pf = load("DD0252")

dd = pf.h.all_data()

print dd.quantities['TotalQuantity']('pcount')



-- 
Stephen Skory
s at skory.us
http://stephenskory.com/
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