asa005, a Python code which evaluates the lower tail of the noncentral T distribution, by BE Cooper.

asa005() is a version of Applied Statistics Algorithm 5.


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


asa005 is available in a C version and a C++ version and a Fortran90 version and a MATLAB version and a Python version.

Related Data and Programs:

owen, a Python code which evaluates Owen's T function.


Original FORTRAN77 version by BE Cooper; Python version by John Burkardt.


  1. BE Cooper,
    Algorithm AS 5: The Integral of the Non-Central T-Distribution,
    Applied Statistics,
    Volume 17, Number 2, 1968, page 193.

Source Code:

Last revised on 12 August 2022.