[Numpy-discussion] Scipy 2017 NumPy sprint

[Peter Creasey]

> From: Marten van Kerkwijk <m.h.vankerkwijk at gmail.com>
>
> Though based on my experience with Quantity, I'd also argue that the
> more annoying problems are not so much with `ndarray` itself, but
> rather with the helper functions.

Just to give an alternative view - as another astronomer I would say
that concerns about the use of subclassing in Astropy is one of the
reasons I rarely use it.

To take an example, if I’m relying on the Quantity class to keep track
of my units, then if I have an (N,3) array-like of positions in
parsecs, that’s just one step away from going through the
sausage-machine of scipy.spatial.cKDTree.query (to find distances to
neighbours) and my units are toast.

That probably sounds stronger than I meant - keeping track of units
systematically is neither easy nor unimportant and I have enormous
respect for the developers of Astropy and the community they have
built around it.

Peter Creasey