ASA032
the Incomplete Gamma Function

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

ASA032 is Applied Statistics Algorithm 32. 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:

ASA032 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:

ASA147, a C++ library which evaluates the incomplete Gamma function.

ASA239, a C++ library which evaluates the incomplete Gamma function.

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

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

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

TEST_VALUES, a C++ 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; C++ 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.cpp, the source code.
• asa032.hpp, the include file.
• asa032.sh, commands to compile the source code.

Examples and Tests:

• asa032_prb.cpp, a sample calling program.
• asa032_prb.sh, commands to compile and run the sample program.
• asa032_prb_output.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 C++ source codes.