polyreg - Data Points Nth Order Polynomial Regression

This function fits a polynomial of order n to a given data points (x,y) using regression techniques

% polyreg
% This function fits a polynomial of order n to a given data points (x,y)
% using regression techniques
% ----------------------------------------------
% inputs
% x x points
% y f(x)
% n polynomial order; 1 for linear
% ----------------------------------------------
% output
% sol.constants constants that need to be found
% sol.fn curve fittin-g function
% sol.syx the standard erro of the estimate
% sol.sr the best fit criterion
% sol.r2 the coefficient of determination; 1 is the best value
% sol.std standard deviation
% ----------------------------------------------
% Example
% x=[1,4,2,4];
% y=[.9 3 10 15];
% n=1;
% sol = polyreg(x,y,n);
% ----------------------------------------------
%
% All copyrights goes to Mohammad Al-Fetyani
% University of Jordan