[Numpy-discussion] np.equal

[Keith Goodman]

On Sun, Dec 6, 2009 at 4:57 AM,  <josef.pktd at gmail.com> wrote:
> what's the difference in the implementation between np.equal and == ?
> np.equal raises NotImplemented for strings, while == works.
>
>>>> aa
> array(['a', 'b', 'a', 'aa', 'a'],
>      dtype='|S2')
>
>>>> aa == 'a'
> array([ True, False,  True, False,  True], dtype=bool)
>>>> np.equal(aa,'a')
> NotImplemented
>
>
>>>> np.equal(np.arange(5),1)
> array([False,  True, False, False, False], dtype=bool)
>>>> np.equal(np.arange(5),'a')
> NotImplemented
>>>> np.arange(5) == 'a'
> False

Seems like none of the ufuncs can handle strings:

>> np.log('a')
   NotImplemented
>> np.exp('a')
   NotImplemented
>> np.add('a', 'b')
   NotImplemented
>> np.negative('a')
   NotImplemented
>> np.sin('a')
   NotImplemented