Bizarre arithmetic results

[Andre Engels]

On Thu, Feb 11, 2010 at 1:44 AM, Terrence Cole
<list-sink at trainedmonkeystudios.org> wrote:
> Can someone explain to me what python is doing here?
>
> Python 3.1.1 (r311:74480, Feb  3 2010, 13:36:47)
> [GCC 4.3.4] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
>>>> -0.1 ** 0.1
> -0.7943282347242815
>>>> a = -0.1; b = 0.1
>>>> a ** b
> (0.7554510437117542+0.2454609236416552j)
>>>> -abs(a ** b)
> -0.7943282347242815
>
> Why does the literal version return the signed magnitude and the
> variable version return a complex?

It's an issue of precedence of operators:

-0.1 ** 0.1

is interpreted as

-(0.1 ** 0.1)

and not as

(-0.1) ** 0.1






-- 
André Engels, andreengels at gmail.com