[Numpy-discussion] __numpy_ufunc__

[Charles R Harris]

Hi All,

Does anyone remember discussion of numpy scalars apropos __numpy_ufunc__?

Chuck

[Stephan Hoyer]

I'm happy to revisit the __numpy_ufunc__ discussion (I still want to see it
happen!), but I don't recall scalars being a point of contention.

The obvious thing to do with scalars would be to treat them the same as
0-dimensional arrays, though I might be missing some nuance...

Post by Charles R Harris
Hi All,
Does anyone remember discussion of numpy scalars apropos __numpy_ufunc__?
Chuck
_______________________________________________
NumPy-Discussion mailing list
https://mail.scipy.org/mailman/listinfo/numpy-discussion

[Charles R Harris]

Post by Stephan Hoyer
I'm happy to revisit the __numpy_ufunc__ discussion (I still want to see
it happen!), but I don't recall scalars being a point of contention.

The __numpy_ufunc__ functionality is the last bit I want for 1.12.0, the
rest of the remaining changes I can kick forward to 1.13.0. I will start
taking a look tomorrow, probably starting with Nathaniel's work.

Post by Stephan Hoyer
The obvious thing to do with scalars would be to treat them the same as
0-dimensional arrays, though I might be missing some nuance...

That's my thought. Currently they just look at __array_priority__ and call
the corresponding array method if needed, so that maybe needs some
improvement and a formal statement of intent.

Chuck

[Marten van Kerkwijk]

Post by Charles R Harris
The __numpy_ufunc__ functionality is the last bit I want for 1.12.0, the
rest of the remaining changes I can kick forward to 1.13.0. I will start
taking a look tomorrow, probably starting with Nathaniel's work.

Great! I'll revive the Quantity PRs that implement __numpy_ufunc__!

-- Marten

[Marten van Kerkwijk]

Hi Chuck,

I've revived my Quantity PRs that use __numpy_ufunc__ but is it
correct that at present in *dev, one cannot use it?

All the best,

Marten

[Charles R Harris]

On Mon, Oct 31, 2016 at 11:08 AM, Marten van Kerkwijk <

Post by Marten van Kerkwijk
Hi Chuck,
I've revived my Quantity PRs that use __numpy_ufunc__ but is it
correct that at present in *dev, one cannot use it?

It's not enabled yet.

Chuck

[Stephan Hoyer]

Recall that I think we wanted to rename this to __array_ufunc__, so we
could change the function signature:
https://github.com/numpy/numpy/issues/5986

I'm still a little nervous about this. Chunk -- what is your proposal for
resolving the outstanding issues from
https://github.com/numpy/numpy/issues/5844?

On Mon, Oct 31, 2016 at 10:31 AM, Charles R Harris <

Post by Charles R Harris
On Mon, Oct 31, 2016 at 11:08 AM, Marten van Kerkwijk <

Post by Marten van Kerkwijk
Hi Chuck,
I've revived my Quantity PRs that use __numpy_ufunc__ but is it
correct that at present in *dev, one cannot use it?

It's not enabled yet.
Chuck
_______________________________________________
NumPy-Discussion mailing list
https://mail.scipy.org/mailman/listinfo/numpy-discussion

[Charles R Harris]

Post by Stephan Hoyer
Recall that I think we wanted to rename this to __array_ufunc__, so we
could change the function signature: https://github.com/numpy/
numpy/issues/5986
I'm still a little nervous about this. Chunk -- what is your proposal for
resolving the outstanding issues from https://github.com/numpy/
numpy/issues/5844?

We were pretty close. IIRC, the outstanding issue was some sort of
override. At the developer meeting at scipy 2015 it was agreed that it
would be easy to finish things up under the rubric "make Pauli happy". But
that wasn't happening which is why I asked Nathaniel to disable it for
1.10.0. It is now a year later, things have cooled, and, IMHO, it is time
to take another shot at it.

<snip>

Chuck

[Marten van Kerkwijk]

Hi Chuck,

We were pretty close. IIRC, the outstanding issue was some sort of override.

Correct. With a general sentiment of those downstream that it would be
great to merge in any form, as it will be really helpful! (Generic
speedup of factor of 2 for computationally expensive ufuncs (sin, cos,
etc.) that needs scaling in Quantity...)

At the developer meeting at scipy 2015 it was agreed that it would be easy
to finish things up under the rubric "make Pauli happy".

That would certainly make me happy too!

Other items that were brought up (trying to summarize from issues
linked above, and links therein):

1. Remove index argument
2. Out always a tuple
3. Let ndarray have a __numpy_ufunc__ stub, so one can super it.

Here, the first item implied a possible name change (to
__array_ufunc__); if that's too troublesome, I don't think it really
hurts to have the argument, though it is somewhat "unclean" for the
case that only the output has __numpy_ufunc__.

All the best,

Marten