Probabilities.Beta Method

function Beta(x: Double; y: Double): Double;

Beta function B.

#NameDescription
1xx in the Beta function definition
2real.
3yy in the Beta function definition
4real.

Returns: Double - beta function B for given parameters x and y.

Remarks:

The (complete) Euler beta function is defined by:

B(x,y)=integral _0^1 t^(x-1)(1-t)^(y-1) dt = (Gamma(x) Gamma(y))/(Gamma(x+y)) .

Domain: x, y real, neither a non-positive integer (poles of the Gamma function). Defined behavior: computed as sgn*exp(lnGamma(x)+lnGamma(y)-lnGamma(x+y)),
carrying the combined sign of the three Gamma factors; the function is symmetric, B(x,y)=B(y,x)B(x,y)=B(y,x). When lnGamma(x+y) overflows the result is 0; when lnGamma(x) or lnGamma(y) overflows the result saturates to the signed maximum value.

See Also: Math387.IGamma