ASA147
the Incomplete Gamma Function

ASA147 is a FORTRAN90 library which evaluates the incomplete Gamma function, by Chi Leung Lau.

ASA147 is Applied Statistics Algorithm 147.

Languages:

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

Related Data and Programs:

ASA032, a FORTRAN90 library which evaluates the incomplete Gamma function.

ASA239, a FORTRAN90 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 FORTRAN90 library which evaluates and inverts a number of probabilistic distributions.

TEST_VALUES, a FORTRAN90 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; FORTRAN90 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:

• asa147.f90, the source code.

Examples and Tests:

• asa147_test.f90, a sample calling program.
• asa147_test.txt, the output file.

List of Routines:

• ALNGAM computes the logarithm of the gamma function.
• GAMMA_INC_VALUES returns some values of the incomplete Gamma function.
• GAMMDS computes the incomplete Gamma integral.
• TIMESTAMP prints out the current YMDHMS date as a timestamp.

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