Allow uint32 dtype for coords

[brendancol]

Hey awesome library! I'm really having a blast with it.

One question / comment:

For my purposes, I need the COO array with the largest dtype for coords of uint32.

When I create an array, the COO constructor seems to convert all coord arrays to intp or int64 in my case.
https://github.com/pydata/sparse/blob/master/sparse/coo/core.py#L234

Any thoughts on skipping that astype if coords is already an array?

[hameerabbasi]

Hey!

awesome library! I'm really having a blast with it.

Thanks!

For my purposes, I need the COO array with the largest dtype for coords of uint32.

When I create an array, the COO constructor seems to convert all coord arrays to intp or int64 in my case.
https://github.com/pydata/sparse/blob/master/sparse/coo/core.py#L234

Any thoughts on skipping that astype if coords is already an array?

Unfortunately, we'd love to. In the past, we converted coords to the smallest possible dtype that could hold the data. We had issues with this (overflows and such), two separate bugs were filed that were a result of this, and I discovered a bug or two myself.

After going through the "whack-a-mole" process of squashing bugs left and right, I just decided to make it int64.

If there was a coordinated effort to examine each line of code that assigns to coords for overflows and fix it... I'd be all for it. There have been requests for this in the past.

[hameerabbasi]

However, if we work on #125 or something along those lines, that'd solve your issues, to my understanding, as it has better compression efficiency in the majority of cases.

[eric-wieser]

I've found myself wanting uint16 here too.

In the past, we converted coords to the smallest possible dtype that could hold the data. We had issues with this (overflows and such), two separate bugs were filed that were a result of this, and I discovered a bug or two myself.

Could you link to the commit where you removed this, and to some of the issues?

[hameerabbasi]

#32 is one such issue, and 1447e0f is the commit where this was removed.