/**
* @param n total elements
* @param k chosen elements
* @return Binomial coefficient n choose k
*/
public static double choose(double n, double k) {
n = Math.floor(n + 0.5);
k = Math.floor(k + 0.5);
final double lchoose =
GammaFunction.lnGamma(n + 1.0)
- GammaFunction.lnGamma(k + 1.0)
- GammaFunction.lnGamma(n - k + 1.0);
return Math.floor(Math.exp(lchoose) + 0.5);
}
public static double logChoose(final int n, final int k) {
return GammaFunction.lnGamma(n + 1.0)
- GammaFunction.lnGamma(k + 1.0)
- GammaFunction.lnGamma(n - k + 1.0);
}
