Logarithm of gamma function
Y = gammaln(A)
Y = gammaln(A) returns the logarithm of the gamma function, gammaln(A)
= log(gamma(A)). Input A must be nonnegative
and real. The gammaln command avoids the underflow
and overflow that may occur if it is computed directly using log(gamma(A)).
gamma | gammainc | gammaincinv | psi