# [Numpy-discussion] Any and all NaNs

Keith Goodman kwgoodman@gmail....
Thu May 29 12:22:41 CDT 2008

```On Thu, May 29, 2008 at 9:26 AM, Stéfan van der Walt <stefan@sun.ac.za> wrote:
> 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 :)

Yeah, but then I'd have to change these it's to its:

Docstrings/numpy/ma/extras/polyfit . . . 1 match
...me when y is a 2D array. When full=True, the rank of the scaled
Vandermonde matrix, it's effective rank in light of the rcond value,
its singular values, and the specified ...

Docstrings/numpy/lib/polynomial/polyfit . . . 1 match
...me when y is a 2D array. When full=True, the rank of the scaled
Vandermonde matrix, it's effective rank in light of the rcond value,
its singular values, and the specified ...

Docstrings/numpy/lib/index-tricks/nd-grid . . . 1 match
...However, if the step length is a **complex number** (e.g. 5j),
then the integer part of it's magnitude is interpreted as specifying
the number of points to create between the start...

Docstrings/numpy/lib/-datasource/Repository . . . 1 match
...one base URL. Initialize the Respository with the base URL,
then refer to each file by it's filename only. *Methods*: - exists :
test if the file exists locally or remotely ...

Docstrings/numpy/fft/fftpack/ifft . . . 1 match
...input array is expected to be packed the same way as the output
of fft, as discussed in it's documentation. This is the inverse of
fft: ifft(fft(a)) == a within numerical accuracy...
```