ASA032
the Incomplete Gamma Function

ASA032 is a FORTRAN90 library which evaluates the incomplete Gamma function, by G Bhattacharjee.

ASA032 is Applied Statistics Algorithm 32.

Languages:

ASA032 is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version.

Related Data and Programs:

ASA147, 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 G Bhattacharjee; FORTRAN90 version by John Burkardt.

Reference:

1. G Bhattacharjee,
   Algorithm AS 32: The Incomplete Gamma Integral,
   Applied Statistics,
   Volume 19, Number 3, 1970, pages 285-287.

Source Code:

• asa032.f90, the source code.

Examples and Tests:

• asa032_test.f90, a sample calling program.
• asa032_test.txt, the output file.

List of Routines:

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

You can go up one level to the FORTRAN77 source codes.