1 /* PSPP - a program for statistical analysis.
2 Copyright (C) 2004, 2008, 2009, 2011 Free Software Foundation, Inc.
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation, either version 3 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
19 #include "math/histogram.h"
21 #include <gsl/gsl_histogram.h>
24 #include "libpspp/assertion.h"
25 #include "libpspp/cast.h"
26 #include "math/chart-geometry.h"
28 #include "gl/xalloc.h"
31 histogram_add (struct histogram *h, double y, double c)
33 struct statistic *stat = &h->parent;
34 stat->accumulate (stat, NULL, c, 0, y);
40 acc (struct statistic *s, const struct ccase *cx UNUSED, double c, double cc UNUSED, double y)
42 struct histogram *hist = UP_CAST (s, struct histogram, parent);
44 gsl_histogram_accumulate (hist->gsl_hist, y, c);
49 destroy (struct statistic *s)
51 struct histogram *h = UP_CAST (s, struct histogram, parent);
52 gsl_histogram_free (h->gsl_hist);
58 histogram_create (double bin_width, double min, double max)
61 struct histogram *h = xmalloc (sizeof *h);
62 struct statistic *stat = &h->parent;
63 const short max_sign = max >= 0;
64 const short min_sign = min >= 0;
66 double upper_limit, lower_limit;
70 lower_limit = trunc (2 * abs (min) / bin_width) - 1;
71 lower_limit *= bin_width / 2;
72 lower_limit *= min_sign;
74 upper_limit = trunc (2 * abs(max) / bin_width) + 1;
75 upper_limit *= bin_width / 2;
76 upper_limit *= max_sign;
78 bins = (upper_limit - lower_limit) / bin_width;
80 h->gsl_hist = gsl_histogram_alloc (bins);
82 gsl_histogram_set_ranges_uniform (h->gsl_hist, lower_limit, upper_limit);
84 stat->accumulate = acc;
85 stat->destroy = destroy;