Г(x) – gamma function:
When x ≥ 12 natural logarithm of Gamma function is calculated by partial sum of the series:
When x ϵ (0; 12) function calculation is reduced to the case x > 12 due to consistent application of the rule Г(x) = Г(x + 1)/x or ln(Г(x)) =ln(Г(x + 1)) - ln(x).
See also:
IStatistics.GammaFunc | IStatistics.GammaLn | Library of Methods and Models