Hello Fabien,

## Advertising

> On 5 Aug 2017, at 12:15, Fabien COELHO <coe...@cri.ensmp.fr> wrote:
>
>
> Hello Alik,
>
> I've done some math investigations, which consisted in spending one hour with
> Christian, a statistician colleague of mine. He took an old book out of a
> shelf, opened it to page 550 (roughly in the middle), and explained to me how
> to build a real zipfian distribution random generator.
>
> The iterative method is for parameter a>1 and works for unbounded values. It
> is simple to add a bound. In practice the iterative method is quite
> effective, i.e. number of iterations is typically small, at least if the
> bound is large and if parameter a is not too close to 1.
> I've attached a python3 script which implements the algorithm. It looks like
> magic. Beware that a C implementation should take care of float and int
> overflows.
>
Thank you for the script. I will rewrite it to C and add to the patch soon.
—
Thanks and Regards,
Alik Khilazhev
Postgres Professional:
http://www.postgrespro.com
The Russian Postgres Company
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers