"eric jones" <eric@[...].com>  writes:

>  Reductions and indexing return different types based on the number of
>  dimensions of the input array:
>  
>  >>> b = sum(a)
>  >>> l = len(b) # or whatever
>  
>  This code works happily if "a" is 2 or more dimensions, but will fail if
>  it is 1d because the sum(a) will return a scalar in this case.  To write

And it should fail, because a rank-0 array is not a sequence, so it
doesn't have a length.

But there are valid examples in which it would be nice if scalars
were arrays (but probably if  *all* scalars supported array operations,
not just those that were generated by indexing from arrays):

- a.shape  should return () for a scalar (and (len(a),) for any
           sequence type)

- a.astype(N.Float) should also work for scalars

Similarly, it would be nice if complex operations (real/imaginary
part) would work on integers and floats.

There's one more annoying difference between scalars and arrays of
any rank which I think should be removed in numarray:

  > >> 3 % -2
  -1
  > >> array(3) % 2
  1
  > >> fmod(3, -2)
  1.0

I.e. the mod operation uses fmod() for arrays, but different rules
for standard Python numbers.

Konrad.
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