asa245, a MATLAB code which evaluates the logarithm of the gamma function, by Allan Mcleod;

This is a version of Applied Statistics Algorithm 245.


The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.


asa245 is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version.

Related Data and Programs:


fn, a MATLAB code which approximates elementary and special functions using Chebyshev polynomials, by Wayne Fullerton.

test_values, a MATLAB code which contains sample values for a number of distributions.

toms291, a MATLAB code which evaluates the logarithm of the Gamma function.


Original FORTRAN77 version by Allan Mcleod; Matlab version by John Burkardt.


  1. Cornelius Lanczos,
    A precision approximation of the gamma function,
    SIAM Journal on Numerical Analysis, B,
    Volume 1, 1964, pages 86-96.
  2. Allan Mcleod,
    Algorithm AS 245: A Robust and Reliable Algorithm for the Logarithm of the Gamma Function,
    Applied Statistics,
    Volume 38, Number 2, 1989, pages 397-402.

Source Code:

Last revised on 27 November 2018.