8.7 least-sq-test

The purpose of this program is debugging finding the coefficients of a least-squares regression function y=aa[0]+aa[1]*x+aa[2]*x*x for a set of points <xx[1],yy[1]>, ..., <xx[n],yy[n]> and a solution of this function for y=x. The program topdown (see topdown) uses this solution as variable length of the cycle event history window and grammar event history window. Use the option --ww=INT of topdown to forcibly set the length (width) of those windows to a constant value.

Invoke the program least-sq-test using the following command-line format:

$ least-sq-test xx[1]:yy[1] xx[2]:yy[2] ... xx[n]:yy[n]

Example:

$ least-sq-test 1:8 2:17 8:29 9:24 11:8
"aa" : [
    -3.000000000000114,
    12.000000000000062,
    -1.000000000000005
],
"xx" : 0.279846745544734

This output means that the least-squares regression function for the set of points <1, 8>, <2, 17>, <8, 29>, <9, 24>, and <11, 8> is y=-3+12x-x², and that -3+12x-x² is approximately equal to 0.279846745544734 for x=0.279846745544734.