Re: [Numpy-discussion] Output type of round is inconsistent with python built-in

On Wed, Feb 26, 2020 at 6:59 PM wrote:

On Wed, Feb 26, 2020 at 6:09 PM Robert Kern wrote:

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On Wed, Feb 26, 2020 at 5:27 PM wrote:

...

great another object array

np.asarray([round(x_i.item()) for x_i in np.array([1, 2.5, 2e20, 2e200])]) array([1, 2, 200000000000000000000,

199999999999999993946624442502072331894900655091004725296483501900693696871108151068392676809412503736055024831947764816364271468736556969278770082094479755742047182133579963622363626612334257709776896], dtype=object)

I would rather have numpy consistent with numpy than with python

Since round() (and the __round__() interface) is part of Python and not numpy, there is nothing in numpy to be consistent with. We only implement __round__() for the scalar types.

Maybe I misunderstand

I'm using np.round a lot. So maybe it's a question whether and how it will affect np.round.

Nope, not changing.

Does the following change with the proposal?

np.round(np.array([1, 2.5, 2e20, 2e200])) array([1.e+000, 2.e+000, 2.e+020, 2.e+200])

np.round(np.array([1, 2.5, 2e20, 2e200])).astype(int) array([ 1, 2, -2147483648, -2147483648])

np.round(np.array([2e200])[0]) 2e+200

np.round(2e200) 2e+200

No change.

round(2e200)

199999999999999993946624442502072331894900655091004725296483501900693696871108151068392676809412503736055024831947764816364271468736556969278770082094479755742047182133579963622363626612334257709776896

Obviously, not under out control, but no, that's not changing. This is the only result that will change: round(np.float64(2e200)) 2e+200

Josef "around 100" sounds like "something all_close(100)"

I know. It's meant to be read as "array-round". We prefer the `around()` spelling to avoid shadowing the built-in. Early mistake that we're still living with. -- Robert Kern