public static double binomialCoefficientLn(int n, int k)
{
QL_REQUIRE(n >= k, () => "n<k not allowed");
return(Factorial.ln(n) - Factorial.ln(k) - Factorial.ln(n - k));
}
private double calcSummand(uint index)
{
return(Math.Exp(-lambda_) * Math.Pow(lambda_, index) / Factorial.get(index));
}