NAME
     wnrndd -- random distribution

SYNOPSIS
     #include "wnrndd.h"

     bool wn_true_with_probability(double prob)

     int wn_random_int_between(int low,int high)

     double wn_random_double_between(double low,double high)

     double wn_flat_distribution(void)

     double wn_normal_distribution(void)

     double wn_exponential_distribution(void)

     int wn_poisson_distribution(double mean)

DESCRIPTION
     These routines generate random numbers with various probability
     distributions, using wnrnd.

     "wn_true_with_probability" returns (randomly) TRUE with probability "prob"
     and FALSE with probability 1-prob.

     "wn_random_int_between" returns a randomly chosen integer in the
     range [low,high).  "low" is in the range; "high" is not.

     "wn_random_double_between" returns a randomly chosen double in the
     range (low,high).  It will never return "low" or "high".

     "wn_flat_distribution" is equivalent to 
     "wn_random_double_between(0.0,1,0)".

     "wn_normal_distribution" returns a double randomly chosen according
     to a normal (gaussian) probability density with mean = 0 and
     standard deviation = 1.

     "wn_exponential_distribution" returns a double randomly chosen according
     to an exponential probability density with mean = 1.  An exponential
     probability density function has values 

       p(x) = exp(-x)    for all x >= 0

       p(x) = 0          for all x <  0

     "wn_poisson_distribution" returns an integer randomly chosen according
     to a Poisson distribution with mean "mean".

BUGS

SEE ALSO
     wnrnd

AUTHOR
     Will Naylor