Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!iguana.cis.ohio-state.edu!adkins
From: adkins@iguana.cis.ohio-state.edu (Brian Adkins)
Newsgroups: comp.lang.c
Subject: Re: Normal distribution random number generator -- WANTED
Keywords: random number generator
Message-ID: <86482@tut.cis.ohio-state.edu>
Date: 2 Dec 90 19:13:19 GMT
References: <1015@qusung.queensu.CA>
Sender: news@tut.cis.ohio-state.edu
Reply-To: Brian Adkins <adkins@cis.ohio-state.edu>
Organization: Ohio State University Computer and Information Science
Lines: 20

>I am looking for C source code to generate normal distribution
>random numbers. I want to be able to generate random numbers
>in the range of 0 - N (N could be equal to 9999, 99999 or 999999) that 
>have normal distribution with mean, say, u and standard deviation s.

I'm not sure if this is exactly what you want, but the Box-Muller method
takes a pair of independent uniform variables ("regular random numbers") 
and creates a pair of standard normal variables:

   z1 = sqrt(-ln(u2)) * cos(2*PI*u1)
   z2 = sqrt(-ln(u2)) * sin(2*PI*u1)

where the angle is expressed in radians.  You probably can convert from 
standard normal variables to the specific case, but for completeness:

   x1 = u + s * z1,  x2 = u + s * z2   where u is mean, s is std. dev.

this method is almost universally preferred over solving for r = F(z)

most of this info is from "Probability & Statistics for Engineers" Miller...


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