llsq, a Python code which solves the linear least squares problem of finding the formula of a straight line y=a*x or y=a*x+b which minimizes the root-mean-square error to a set of N data points.
The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.
llsq is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version and a Python version.
test_lls, a Python code which implements linear least squares (LLS) test problems of the form A*x=b.