jburkardt

ASA091\ Percentage Points of the Chi-Squared Distribution {#asa091-percentage-points-of-the-chi-squared-distribution align=”center”} =================================================

---

ASA091 is a C++ library which computes the percentage points of the Chi-Squared probability distribution, by Best and Roberts.

ASA091 is Applied Statistics Algorithm 91. Source code for many Applied Statistics Algorithms is available through STATLIB.

Licensing: {#licensing align=”center”}

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

Languages: {#languages align=”center”}

ASA091 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: {#related-data-and-programs align=”center”}

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.

NORMAL, a C++ library which samples the normal distribution.

PROB, a FORTRAN90 library which evaluates and inverts many probability distibutions.

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

UNIFORM, a C++ library which samples the uniform distribution.

Author: {#author align=”center”}

Original FORTRAN77 version by Donald Best and DE Roberts; C++ version by John Burkardt.

Reference: {#reference align=”center”}

1. Donald Best, DE Roberts,\ Algorithm AS 91: The Percentage Points of the Chi-Squared Distribution,\ Applied Statistics,\ Volume 24, Number 3, 1975, pages 385-390.
2. William Cody, Kenneth Hillstrom,\ Chebyshev Approximations for the Natural Logarithm of the Gamma Function,\ Mathematics of Computation,\ Volume 21, Number 98, April 1967, pages 198-203.
3. John Hart, Ward Cheney, Charles Lawson, Hans Maehly, Charles Mesztenyi, John Rice, Henry Thacher, Christoph Witzgall,\ Computer Approximations,\ Wiley, 1968,\ LC: QA297.C64.
4. BL Shea,\ Algorithm AS 239: Chi-squared and Incomplete Gamma Integral,\ Applied Statistics,\ Volume 37, Number 3, 1988, pages 466-473.
5. Michael Wichura,\ Algorithm AS 241: The Percentage Points of the Normal Distribution,\ Applied Statistics,\ Volume 37, Number 3, 1988, pages 477-484.

Source Code: {#source-code align=”center”}

• asa091.cpp, the source code.
• asa091.hpp, the include file.

Examples and Tests: {#examples-and-tests align=”center”}

• asa091_prb.cpp, a sample calling program.
• asa091_prb_output.txt, the output file.

List of Routines: {#list-of-routines align=”center”}

• CHI_SQUARE_CDF_VALUES returns some values of the Chi-Square CDF.
• GAMMAD computes the Incomplete Gamma Integral
• PPCHI2 evaluates the percentage points of the Chi-squared PDF.
• R8_NORMAL_CDF_INVERSE inverts the normal CDF.
• R8POLY_VALUE evaluates a double precision polynomial.
• TIMESTAMP prints the current YMDHMS date as a time stamp.

You can go up one level to the C++ source codes.

---

Last revised on 05 February 2008.