[Numpy-discussion] Python scalar float indices into array work - but not for array indices - why ?

Robert Kern robert.kern@gmail....
Wed Nov 17 12:26:21 CST 2010

On Wed, Nov 17, 2010 at 12:20, Sebastian Haase <seb.haase@gmail.com> wrote:
> Hi,
>>>> import numpy as np
>>>> a = np.arange(4)
>>>> a[1.8]
> 1
>>>> a[ np.array(1.8) ]
> Traceback (most recent call last):
>  File "<input>", line 1, in <module>
> IndexError: arrays used as indices must be of integer (or boolean) type
> Why does numpy not accept float arrays as indices ?
> I was very happy and quite surprised once I found out that it worked
> at all for Python float scalars,
> but would it not just be consequent to also allow float ndarrays then ?

It only works for float scalars by accident. Do not rely on it.

Robert Kern

"I have come to believe that the whole world is an enigma, a harmless
enigma that is made terrible by our own mad attempt to interpret it as
though it had an underlying truth."
  -- Umberto Eco

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