Subject: Re: System clock resolution and random numbers
To: Perry E. Metzger <perry@piermont.com>
From: John C. Hayward <John.C.Hayward@wheaton.edu>
List: current-users
Date: 05/01/1997 01:24:00
On Wed, 30 Apr 1997, Perry E. Metzger wrote:

> 
> "John C. Hayward" writes:
> > Use random - it has a larger facility than 2^32 (from man 3 random)
> > ===
> >      The random() function uses a non-linear additive feedback random number
> >      generator employing a default table of size 31 long integers to return
> >      successive pseudo-random numbers in the range from 0 to (2**31)-1.
> >      The period of this random number generator is very large, approximately
> >      16*((2**31)-1).
> > ===
> > This should be large enough for _any_ application.
I should have said for the 256 long integer which has a period of > 2^69.
> 
> Not for cryptography. Not by a long shot.
> 
> Also, that random number generator pretty much sucks for many classes
> of monte carlo simulations.
If you compute at the rate of 1 billion events per second (~2^30) for
a year (~2^25 seconds) it would take 2^14 years to cycle for the 256 long
integer state.

johnh...
> 
> Perry
>