Re: [SciPy-dev] [Numpy-discussion] Re: How to handle a[...] in numpy?

[Sasha <nd...@ma...>]

Sorry, forgot to attach.

On 1/9/06, Sasha <nd...@ma...> wrote:
> Attached patch implements indexing of zero rank arrays:
>
> >>> x =3D array(42)
> >>> x[...]
> 42
> >>> x[()]
> 42
> >>> x[()].dtype
> <type 'int32_arrtype'>
> >>> type(x[()])
> <type 'int32_arrtype'>
>
> Ellipsis and empty tuple are the only two valid indices.
>
> So far there was only one +1 vote for the feature (from Francesc
> Altet, who also suggested  that x[()] be allowed).  Does anyone object
> to this feature?
>
> I have also proposed to support x[...,newaxis] (see comment by
> sdementen at http://www.scipy.org/wikis/numdesign/).  I will add this
> feature if there is interest.
>
> Finally, if we make x[...] valid for rank-0 arrays, should x[...] =3D
> value be allowed as well? I think it should, applying the principle of
> least surprized.  An additional consideration is that rank-0 arrays
> are unhashable, but there is no obvious way to change their values.
>
> The following example show that rank-0 arrays are in fact mutable (in
> a non-obvious way):
>
> >>> x =3D array(1)
> >>> x.shape=3D(1,); x[0] =3D 42; x.shape=3D()
> >>> x
>
> Please comment on the following proposals:
>
> 1. x[...]
> 2. x[...] =3D value
> 3. x[..., newaxis]
>
>
> -- sasha
>