[Numpy-discussion] 1.8.0rc1

Sebastian Berg sebastian at sipsolutions.net
Wed Oct 2 06:54:45 EDT 2013


On Wed, 2013-10-02 at 10:04 +0100, Nathaniel Smith wrote:
> This is a complicated issue to describe but i think the bottom line is
> that the test is just wonky here. the behaviour it's checking for is:
> wrong in old numpy, but we do it anyway (bug)
> wrong in current numpy without RELAXED_STRIDES, and we get it right
> (I.e. don't do it, fixed bug)
> correct in current numpy with RELAXED_STRIDES (and I think the test
> will pass if you build 1.8 this way?) (fixed bug again, since the
> definition of "correct" flipped)
> correct in future numpys
> 
Sounds about right, but I did not yet look at the test exactly. The old
numpy had some corner cases where the *not* relaxed strides were not
enforced. I could imagine that the test was written to accommodate the
relaxed strides, but runs through fine with the old behaviour, too.

That said, if this is the case, this must be something like a size 1
array corner case, so I would agree with Nathaniel, that probably the
test should just see whether relaxed strides is active or not and change
behaviour accordingly.

If this has to do with the Buffer protocol change we have to have a
closer look if it might be breaking code out there. (even if the buffer
protocol change is correct and this should be fixed on cythons end in
that case)

- Sebastian


> (@seberg, does that look right?)
> 
> I guess maybe we could go back and make sure it stays broken in 1.8,
> but it's probably not worth the trouble because this is such a corner
> case. Nothing real is going to break because of this AFAICT.
> 
> -n
> 
> On 2 Oct 2013 08:31, "Christoph Gohlke" <cgohlke at uci.edu> wrote:
>         On 9/30/2013 8:17 AM, Charles R Harris wrote:
>                 Hi All,
>                 
>                 NumPy 1.8.0rc1 is up now on sourceforge
>                 <http://sourceforge.net/projects/numpy/files/NumPy/1.8.0rc1/> .The
>                 binary builds are included except for Python 3.3 on
>                 windows, which will
>                 arrive later. Many thanks to Ralf for the binaries,
>                 and to those who
>                 found and fixed the bugs in the last beta. Any
>                 remaining bugs are all my
>                 fault ;) I hope this will be the last release before
>                 final, so please
>                 test it thoroughly.
>                 
>                 Chuck
>                 
>         
>         One more: Cython-0.19.1 fails relaxed_strides.test_one_sized
>         with "ValueError: ndarray is not C-contiguous". Tested on
>         numpy-MKL-1.8.0rc1-win-amd64-py2.7 and msvc9.
>         
>         https://github.com/cython/cython/blob/0.19.x/tests/memoryview/relaxed_strides.pyx#L29
>         
>         The relevant test output is attached.
>         
>         Christoph
>         
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