ASA243 is a C library which computes the cumulative density function (CDF) of the noncentral Student's T probability density function, by Russell Lenth.
ASA243 is Applied Statistics Algorithm 243. Source code for many Applied Statistics Algorithms is available through STATLIB.
The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.
ASA243 is available in a C version and a C++ version and a FORTRAN77 version and a FORTRAN90 version and a MATLAB version
ASA005, a C library which evaluates the CDF of the noncentral T distribution.
ASA076, a C library which evaluates the Owen's T function, needed to compute the CDF of the noncentral T distribution.
OWENS, a C library which evaluates Owen's T function.
Original FORTRAN77 version by Russell Lenth; C version by John Burkardt.
You can go up one level to the C source codes.