#define	PROBMAXVIZ	(50)

double	pmuteviz[PROBMAXVIZ];



to initialize:

	VizProbs(pmuteviz,beta);



to get a number:

	nviz = ProbEvent(pmuteviz);




VizProbs(dist,mean)
double mean, dist[PROBMAXVIZ];
{
	int i;
	double	term;
	
	dist[0] = term = exp(-mean);
	for(i=1;i<PROBMAXVIZ-1;i++)
	{
		term *= (mean / (double)i);
		dist[i] = dist[i-1]  + term;
	}
	dist[PROBMAXVIZ-1] = 1.0;
}

int ProbEvent(dist)
double dist[PROBMAXVIZ];
{
	int i=0;
	double	term;
	
	term = drand48();
	while(dist[i]<term) i++;
	return(i);
}