1 /* statistics/wabsdev_source.c
3 * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2007 Jim Davies, Brian Gough
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 3 of the License, or (at
8 * your option) any later version.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
21 FUNCTION(gsl_stats,wabsdev) (const BASE w[], const size_t wstride, const BASE data[], const size_t stride, const size_t n)
23 const double wmean = FUNCTION(gsl_stats,wmean)(w, wstride, data, stride, n);
24 return FUNCTION(gsl_stats,wabsdev_m)(w, wstride, data, stride, n, wmean);
28 FUNCTION(gsl_stats,wabsdev_m) (const BASE w[], const size_t wstride, const BASE data[], const size_t stride, const size_t n, const double wmean)
30 /* Compute the weighted absolute deviation of a dataset */
32 long double wabsdev = 0;
37 /* find the sum of the absolute deviations */
38 for (i = 0; i < n; i++)
40 BASE wi = w[i * wstride];
43 const long double delta = fabs(data[i * stride] - wmean);
45 wabsdev += (delta - wabsdev) * (wi / W);