Simple linear regression finction for Scilab

Scilab linear regression

function [a,b]=linlsq(X,Y)
    [n,m]=size(X);
    n=n*m;
    sumx = sum(X);
    sumy = sum(Y);
    sumxx = sum(X.*X);
    sumxy = sum(X.*Y);
    a=(sumx*sumy-n*sumxy)/(sumx*sumx-n*sumxx);
    b=(sumy-a*sumx)/n;
endfunction