Function to evaluate the complement of the RegularizedBeta

The RegularizedBeta class computes the regularized beta function I(x, a, b). There is a functional identity for this:

1 - I(x, a, b) = I(1 - x, b, a)

See Wolfram Regularized Incomplete Beta Identities

The RegularizedBeta class currently exploits this identity to compute the value by switching to call '1.0 - value(1 - x, b, a)' depending on the parameters.

I suggest a complement for this function to compute 1 - I(x, a, b):

public class RegularizedBetac {
    public static double value(double x,
                               final double a,
                               final double b,
                               double epsilon,
                               int maxIterations);     
}

This can call RegularizedBeta.value using the same inversion logic and avoid a potential computation of the complement using multiple inversions with loss of precision:

1 - I(x, a, b) == 1 - [ 1 - I(1 - x, b, a) ] = I(1 - x, b, a)

or

I(1 - x, b, a) == 1 - I(x, a, b) = 1 - [ 1 - I(1 - x, b, a) ]