public static double Binomial(params double[] arguments)
{
double n = arguments[0];
double k = arguments[1];
return(DoOperators.Factorial(n) / (DoOperators.Factorial(k) * DoOperators.Factorial(n - k)));
}
public static double Gamma(params double[] arguments)
{
//If args[0] is an integer use factorials
if ((int)arguments[0] == arguments[0])
{
return(DoOperators.Factorial(arguments[0] - 1));
}
//Gergő Nemes Approximation
//https://en.wikipedia.org/wiki/Stirling%27s_approximation
double z = arguments[0];
return(Math.Sqrt((2 * Math.PI) / z) * Math.Pow((1 / Math.E) * (z + 1 / (12 * z - 1 / (10 * z))), z));
}