Beta function
B = beta(Z,W)
B = beta(Z,W)
computes
the beta function for corresponding elements of arrays Z
and W
.
The arrays must be real and nonnegative. They must be the same size,
or either can be scalar.
In this example, which uses integer arguments,
beta(n,3) = (n-1)!*2!/(n+2)! = 2/(n*(n+1)*(n+2))
is the ratio of fairly small integers, and the rational format is able to recover the exact result.
format rat beta((0:10)',3) ans = 1/0 1/3 1/12 1/30 1/60 1/105 1/168 1/252 1/360 1/495 1/660
beta(z,w) = exp(gammaln(z)+gammaln(w)-gammaln(z+w))