Example: Line Fit (continued)
/* Compute coefficients. */ { double sx_over_n = sx / n; double stt = 0.0; double b = 0.0; double a; { int i; for ( i = 0; i < n; i++ ) { double ti = x[i] - sx_over_n; stt += ti * ti; b += ti * y[i]; } } b /= stt; a = (sy - sx*b) / n; free (x); free (y); if ( b >= 0 ) { printf ("Solution: y = %e + %e*x\n", a, b); } else { printf ("Solution: y = %e - %e*x\n", a, -b); } } } int main () { linefit (); return 0; }