[Numpy-discussion] ufunc oddities

Charles R Harris charlesr.harris@gmail....
Sat May 24 22:48:11 CDT 2008


On Sat, May 24, 2008 at 9:40 PM, Nathan Bell <wnbell@gmail.com> wrote:

> On Sat, May 24, 2008 at 10:32 PM, Charles R Harris
> <charlesr.harris@gmail.com> wrote:
> >
> > But the accumalator is of the same kind unless the kind is boolean, in
> which
> > case it is integer. Clear as a bell.
> >
>
> I believe the rule is that any integer type smaller than the machine
> word size is effectively upcast.
>
> IMO this is desirable since small types are very likely to overflow.
>

You can't overflow in modular arithmetic, which is how numpy is supposed to
work. Try

In [51]: x
Out[51]: array([2147483647, 2147483647])

In [52]: x.sum()
Out[52]: -2

Chuck
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