1 /* leastsqs.h -- Implements a simple linear least squares best fit routine
3 * Written by Curtis Olson, started September 1997.
5 * Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 * (Log is kept at end of this file)
31 n*sum(xi*yi) - (sum(xi)*sum(yi))
32 b1 = --------------------------------
33 n*sum(xi^2) - (sum(xi))^2
36 b0 = sum(yi)/n - b1*(sum(xi)/n)
39 void least_squares(double *x, double *y, int n, double *m, double *b);
43 return the least squares error:
49 double least_squares_error(double *x, double *y, int n, double m, double b);
53 return the maximum least squares error:
57 double least_squares_max_error(double *x, double *y, int n, double m, double b);
61 /* Revision 1.1 1998/03/19 02:54:48 curt
62 /* Reorganized into a class lib called fgDEM.
64 * Revision 1.1 1997/10/13 17:02:35 curt