Hypergeometric distribution

[Raven]

Travis E. Oliphant wrote:

> Notice the keyword for the comb function (in scipy) lets you use it to
> compute exact values.   SciPy does not just automatically use the long
> integer because this will always slow you down.
>
> comb(N, k, exact=0)
>
> Combinations of N things taken k at a time.
>
> If exact==0, then floating point precision is used, otherwise
> exact long integer is computed.
>
> Notes:
>    - Array arguments accepted only for exact=0 case.
>    - If k > N, N < 0, or k < 0, then a 0 is returned.
> 
> -Travis Oliphant

Great, thanks Travis.
Ale