[Yt-dev] HDF5 HaloFinder preloading

[Matthew Turk]

> alldata = self.pf.h.all_data()
> n_parts = alldata.quantities["TotalQuantity"](["gridNumberOfParticles"], lazy_reader=True,
>    preload=True)[0]
>
>
> Am I doing something wrong? Thanks!

Yes.  TotalQuantity works for field quantities, which
gridNumberOfParticles is not.

n_parts = self.pf.h.gridNumberOfParticles.sum()

-Matt