[Numpy-discussion] np.isfinite on structured arrays

[Pierre GM]

All,
Consider the following code:
 >>> a = np.array(zip(np.arange(3)),dtype=[('a',float)])
 >>> np.isfinite(a)
NotImplemented

That is, when the input is a structured array, np.isfinite returns an  
object of type NotImplementedType. I would have expected it to raise a  
NotImplementedError exception.

Can anybody cast some light on this issue ?
Thanks a lot in advance
P.