/// <summary>
/// Returns a probability based on those given in 3.8
/// </summary>
/// <param name="u"></param>
/// <param name="eta"></param>
/// <returns></returns>
private double probability(int u, double eta)
{
int l;
double sum, p;
if (u == 0)
{
p = Math.Exp(-eta);
}
else
{
sum = 0.0;
for (l = 1; l <= u; l++)
{
sum += Math.Exp(-eta - u * Math.Log(2) + l * Math.Log(eta) - Cephes.lgam(l + 1) + Cephes.lgam(u) - Cephes.lgam(l) - Cephes.lgam(u - l + 1));
}
p = sum;
}
return(p);
}
