Array ufunc multiplication

[andrewgsavage]

• Closes Operations between arrays of quantity scalars and quantity holding array resulting in incorrect units #1674
• Executed pre-commit run --all-files with no errors
• The change is fully covered by automated unit tests
• Documented in docs/ as appropriate
• Added an entry to the CHANGES file

[burnpanck]

This doesn't look quite right to me: You start from an dtype=object array of quantity scalars, where each element could potentially be of a different unit. The result is now a "normal" quantity array, where all elements share a single unit.

Please add a test case for arr_of_q = np.array([Q_(2, "m"), Q_(4, "s")], dtype="object").

Obviously, this will not work with a quantity array, and the expected result of arr_of_q * q_arr would be np.array([Q_(2, "m^2"), Q_(4, "m s")], dtype="object"). For consistency, I would have expected to receive a dtype=object array in all cases.

[hgrecco]

@andrewgsavage can you comment on @burnpanck objection?

[andrewgsavage]

yea hold merging off till it's addressed

[andrewgsavage]

numpy tests are working on numpy 1.23 but failing on 1.25

I was getting this message for the failing test on 1.23
F:\A\repos\pint\pint\compat.py:306: DeprecationWarning: elementwise comparison failed; this will raise an error in the future.
out = lhs == rhs

[andrewgsavage]

this is ready for review

[codspeed-hq]

CodSpeed Performance Report

Merging #1677 will degrade performances by 31.5%

_{Comparing andrewgsavage:array_ufunc_multiplication (02f0209) with master (cb0ec94)}

Summary

❌ 1 regressions
✅ 436 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	master	andrewgsavage:array_ufunc_multiplication	Change
❌	test_build_by_mul[mid_array]	12 ms	17.6 ms	-31.5%

[andrewgsavage]

Can this be reviewed? I'd like to make pint-pandas changes that rely on this.

[burnpanck]

Sorry, I didn't realise that I was listed as a reviewer (probably added automatically by my previous comment). I feel honoured that you are interested in my review, but I'm by no means a maintainer of pint or any related project, so I'm no authority here. I'm just an occasional contributor who likes failures to be loud instead of silent (and thus a big advocate of units libraries in any language).

[andrewgsavage]

this is ready for another look

[burnpanck]

LGTM