TOMS291
Approximate Log(Gamma(X))

TOMS291 is a MATLAB program, using double precision arithmetic, which approximates the logarithm of the Gamma function.

The text of many ACM TOMS algorithms is available online through ACM: http://www.acm.org/pubs/calgo or NETLIB: http://www.netlib.org/toms/index.html.

Related Data and Programs:

ASA245 is a MATLAB library which evaluates the logarithm of the Gamma function.

GSL is a C++ library which evaluates many special functions, including the logarithm of the Gamma function.

POLPAK is a MATLAB library which evaluates a variety of special functions.

SPECFUN is a FORTRAN77 library which evaluates a variety of special functions.

TEST_VALUES is a MATLAB library which tabulates several values of a variety of special functions.

TOMS291 is also available in a C++ version and a FORTRAN77 version and a FORTRAN90 version.

TOMS708 is a FORTRAN90 library which evaluates several special functions, including the logarithm of the Gamma function.

Reference:

1. Malcolm Pike, David Hill,
   Algorithm 291: Logarithm of Gamma Function,
   Communications of the ACM,
   Volume 9, Number 9, September 1966, page 684.

Source Code:

• alogam.m computes the logarithm of the Gamma function.
• gamma_log_values.m returns some values of the Log Gamma function.
• timestamp.m prints out the current YMDHMS date as a timestamp.

Examples and Tests:

• toms291_test.m, a sample calling program.
• toms291_test01.m, tests ALOGAM.
• toms291_prb_output.txt, the output file.

You can go up one level to the FORTRAN90 source codes.