[Numpy-discussion] Contiguity of result of astype changed - intentional?

Ondřej Čertík ondrej.certik@gmail....
Wed Sep 12 16:24:09 CDT 2012


Hi Matt,

On Wed, Sep 12, 2012 at 1:27 PM, Travis Oliphant <travis@continuum.io> wrote:
>>>>
>>>> Is this intended?  Is there a performance reason to keep the same
>>>> strides in 1.7.0?
>>>
>>> I believe that this could be because in 1.7.0, NumPy was changed so that copying does not always default to "C-order" but to "Keep-order".    So, in 1.7.0, the strides of b is governed by the strides of a, while in 1.6.1, the strides of b is C-order (because of the copy).
>>>
>>
>> Thanks for the reply.
>>
>> So maybe the bottom line is that the user should not assume any
>> contiguity from ``astype``?   If that's the case I'll submit a
>> docstring PR to say that.
>>
>
> Yes, that would be a great addition to the docstring.   Mark, can you confirm this is the desired behavior?  Ondrej, this would be something to put in the release notes, if it isn't already.

If you could submit the PR with the docs, that'd be awesome. In the
meantime, I've created an issue for it:

https://github.com/numpy/numpy/issues/437

and put it into my TODO list:

https://github.com/numpy/numpy/issues/396

Ondrej


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