[Numpy-discussion] Any and all NaNs

Stéfan van der Walt stefan@sun.ac...
Thu May 29 11:26:16 CDT 2008


2008/5/23 Keith Goodman <kwgoodman@gmail.com>:
> On Fri, May 23, 2008 at 11:44 AM, Robert Kern <robert.kern@gmail.com> wrote:
>> On Fri, May 23, 2008 at 12:22 PM, Keith Goodman <kwgoodman@gmail.com> wrote:
>>
>>> But the first example
>>>
>>>>> x = mp.matrix([[mp.nan]])
>>>>> x
>>>   matrix([[ NaN]])
>>>>> x.all()
>>>   True
>>>>> x.any()
>>>   True
>>>
>>> is still surprising.
>>
>> On non-boolean arrays, .all() and .any() check each element to see if
>> it is not equal to 0. NaN != 0. Returning False would be just as
>> wrong. If there were a Maybe in addition to True and False, then
>> perhaps that would be worth changing, but I don't see a reason to
>> change the rule as it is.
>
> That makes sense. Hopefully it will find its way into the doc string.

Hopefully you'll add it there :)

Cheers
Stéfan


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