[Numpy-discussion] ANN: NumPy 1.7.0b2 release

Nathaniel Smith njs@pobox....
Mon Sep 24 17:49:27 CDT 2012


On Mon, Sep 24, 2012 at 10:47 PM, Charles R Harris
<charlesr.harris@gmail.com> wrote:
>
>
> On Mon, Sep 24, 2012 at 2:25 PM, Frédéric Bastien <nouiz@nouiz.org> wrote:
>>
>> Hi,
>>
>> I tested this new beta on Theano and discovered an interface change
>> that was not there in the beta 1.
>>
>> New behavior:
>> numpy.ndindex().next()
>> (0,)
>>
>> Old behavior:
>> numpy.ndindex().next()
>> ()
>>
>> This break some Theano code that look like this:
>>
>> import numpy
>> shape=()
>> out_shape=[12]
>> random_state=numpy.random.RandomState()
>>
>> out = numpy.zeros(out_shape, int)
>> for i in numpy.ndindex(*shape):
>>     out[i] = random_state.permutation(5)
>>
>>
>> I suppose this is an regression as the only mention of ndindex in the
>> first email of this change is that it is faster.
>>
>
> I think this problem has been brought up on the list. It is interesting that
> it turned up after the first beta. Could you do a bisection to discover
> which commit is responsible?

No need, the problem is already known. It was introduced by that
ndindex speed up patch, PR #393, which was backported into the first
beta as well. There's a follow-up patch in PR #445 that fixes both of
these issues, though it also exposes some more fundamental issues with
the nditer API, so there's lots of discussion there about if we want
some more changes... this is a good summary:
https://github.com/numpy/numpy/pull/445#issuecomment-8740982

For 1.7 purposes though the bottom line is that we already have
multiple acceptable solutions, so both the issues reported here should
definitely be fixed.

-n


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