[Numpy-discussion] last call for fixes for numpy 1.8.1rc1

Francesc Alted francesc at continuum.io
Fri Feb 28 07:32:23 EST 2014


Well, what numexpr is using is basically NpyIter_AdvancedNew:

https://github.com/pydata/numexpr/blob/master/numexpr/interpreter.cpp#L1178

and nothing else.  If NPY_MAXARGS could be increased just for that, and 
without ABI breaking, then fine.  If not, we should have to wait until 
1.9 I am afraid.

On the other hand, increasing the temporary arrays in nditer from 32kb 
to 128kb is a bit worrying, but probably we should do some benchmarks 
and see how much performance would be compromised (if any).

Francesc

On 2/28/14, 1:09 PM, Julian Taylor wrote:
> hm increasing it for PyArrayMapIterObject would break the public ABI.
> While nobody should be using this part of the ABI its not appropriate
> for a bugfix release.
> Note that as it currently stands in numpy 1.9.dev we will break this ABI
> for the indexing improvements.
>
> Though for nditer and some other functions we could change it if thats
> enough.
> It would bump some temporary arrays of nditer from 32kb to 128kb, I
> think that would still be fine, but getting to the point where we should
> move them onto the heap.
>
> On 28.02.2014 12:41, Francesc Alted wrote:
>> Hi Julian,
>>
>> Any chance that NPY_MAXARGS could be increased to something more than
>> the current value of 32?  There is a discussion about this in:
>>
>> https://github.com/numpy/numpy/pull/226
>>
>> but I think that, as Charles was suggesting, just increasing NPY_MAXARGS
>> to something more reasonable (say 256) should be enough for a long while.
>>
>> This issue limits quite a bit the number of operands in numexpr
>> expressions, and hence, to other projects that depends on it, like
>> PyTables or pandas.  See for example this bug report:
>>
>> https://github.com/PyTables/PyTables/issues/286
>>
>> Thanks,
>> Francesc
>>
>> On 2/27/14, 9:05 PM, Julian Taylor wrote:
>>> hi,
>>>
>>> We want to start preparing the release candidate for the bugfix release
>>> 1.8.1rc1 this weekend, I'll start preparing the changelog tomorrow.
>>>
>>> So if you want a certain issue fixed please scream now or better create
>>> a pull request/patch on the maintenance/1.8.x branch.
>>> Please only consider bugfixes, no enhancements (unless they are really
>>> really simple), new features or invasive changes.
>>>
>>> I just finished my list of issues I want backported to numpy 1.8
>>> (gh-4390, gh-4388). Please check if its already included in these PRs.
>>> I'm probably still going to add gh-4284 after some though tomorrow.
>>>
>>> Cheers,
>>> Julian
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>>
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-- 
Francesc Alted




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