ASA147
the Incomplete Gamma Function

ASA147 is a MATLAB library which evaluates the incomplete Gamma function, by Chi Leung Lau.

ASA147 is Applied Statistics Algorithm 147. Source code for many Applied Statistics Algorithms is available through STATLIB.

Licensing:

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

Languages:

ASA147 is available in a C version and a C++ version and a FORTRAN77 version and a FORTRAN90 version and a MATLAB version.

Related Data and Programs:

ASA032, a MATLAB library which evaluates the incomplete Gamma function.

ASA239, a MATLAB library which evaluates the incomplete Gamma function.

DCDFLIB, a FORTRAN90 library which evaluates and inverts a number of statistical distributions.

GSL, a C++ library which includes many routines for evaluating probability distributions.

PROB, a MATLAB library which evaluates and inverts a number of probabilistic distributions.

TEST_VALUES, a MATLAB library which contains sample values for a number of distributions.

TOMS435, a FORTRAN77 library which evaluates the modified incomplete Gamma function.

TOMS708, a FORTRAN90 library which includes routines to evaluate the incomplete Gamma function.

Author:

Original FORTRAN77 version by Chi Leung Lau; MATLAB version by John Burkardt.

Reference:

1. Chi Leung Lau,
   Algorithm AS 147: A Simple Series for the Incomplete Gamma Integral,
   Applied Statistics,
   Volume 29, Number 1, 1980, pages 113-114.

Source Code:

• alngam.m computes the logarithm of the gamma function.
• gamma_inc_values.m returns some values of the incomplete Gamma function.
• gammds.m computes the incomplete Gamma integral.
• timestamp.m prints out the current YMDHMS date as a timestamp.

Examples and Tests:

• asa147_test.m, a sample calling program.
• asa147_test01.m, tests GAMMDS.
• asa147_test_output.txt, the output file.

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