asa121, a MATLAB code which evaluates the trigamma function, by BE Schneider. This is a version of Applied Statistics Algorithm 121.
The computer code and data files described and made available on this web page are distributed under the MIT license
asa121 is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version.
asa103, a MATLAB code which evaluates the digamma function.
test_values, a MATLAB code which contains sample values for a number of special functions.
Original FORTRAN77 version by BE Schneider; MATLAB version by John Burkardt.