1 /* histogram/init.c
2  *
3  * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2007 Brian Gough
4  *
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.
9  *
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.
14  *
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.
18  */
19 
20 #include "gsl__config.h"
21 #include <stdlib.h>
22 #include "gsl_errno.h"
23 #include "gsl_histogram.h"
24 
25 gsl_histogram *
26 gsl_histogram_alloc (size_t n)
27 {
28   gsl_histogram *h;
29 
30   if (n == 0)
31     {
32       GSL_ERROR_VAL ("histogram length n must be positive integer",
33                         GSL_EDOM, 0);
34     }
35 
36   h = (gsl_histogram *) malloc (sizeof (gsl_histogram));
37 
38   if (h == 0)
39     {
40       GSL_ERROR_VAL ("failed to allocate space for histogram struct",
41                         GSL_ENOMEM, 0);
42     }
43 
44   h->range = (double *) malloc ((n + 1) * sizeof (double));
45 
46   if (h->range == 0)
47     {
48       free (h);         /* exception in constructor, avoid memory leak */
49 
50       GSL_ERROR_VAL ("failed to allocate space for histogram ranges",
51                         GSL_ENOMEM, 0);
52     }
53 
54   h->bin = (double *) malloc (n * sizeof (double));
55 
56   if (h->bin == 0)
57     {
58       free (h->range);
59       free (h);         /* exception in constructor, avoid memory leak */
60 
61       GSL_ERROR_VAL ("failed to allocate space for histogram bins",
62                         GSL_ENOMEM, 0);
63     }
64 
65   h->n = n;
66 
67   return h;
68 }
69 
70 static void
71 make_uniform (double range[], size_t n, double xmin, double xmax)
72 {
73   size_t i;
74 
75   for (i = 0; i <= n; i++)
76     {
77       double f1 = ((double) (n-i) / (double) n);
78       double f2 = ((double) i / (double) n);
79       range[i] = f1 * xmin +  f2 * xmax;
80     }
81 }
82 
83 gsl_histogram *
84 gsl_histogram_calloc_uniform (const size_t n, const double xmin,
85                               const double xmax)
86 {
87   gsl_histogram *h;
88 
89   if (xmin >= xmax)
90     {
91       GSL_ERROR_VAL ("xmin must be less than xmax", GSL_EINVAL, 0);
92     }
93 
94   h = gsl_histogram_calloc (n);
95 
96   if (h == 0)
97     {
98       return h;
99     }
100 
101   make_uniform (h->range, n, xmin, xmax);
102 
103   return h;
104 }
105 
106 gsl_histogram *
107 gsl_histogram_calloc (size_t n)
108 {
109   gsl_histogram * h = gsl_histogram_alloc (n);
110 
111   if (h == 0)
112     {
113       return h;
114     }
115 
116   {
117     size_t i;
118 
119     for (i = 0; i < n + 1; i++)
120       {
121         h->range[i] = i;
122       }
123 
124     for (i = 0; i < n; i++)
125       {
126         h->bin[i] = 0;
127       }
128   }
129 
130   h->n = n;
131 
132   return h;
133 }
134 
135 
136 void
137 gsl_histogram_free (gsl_histogram * h)
138 {
139   free (h->range);
140   free (h->bin);
141   free (h);
142 }
143 
144 /* These initialization functions suggested by Achim Gaedke */
145 
146 int
147 gsl_histogram_set_ranges_uniform (gsl_histogram * h, double xmin, double xmax)
148 {
149   size_t i;
150   const size_t n = h->n;
151 
152   if (xmin >= xmax)
153     {
154       GSL_ERROR ("xmin must be less than xmax", GSL_EINVAL);
155     }
156 
157   /* initialize ranges */
158 
159   make_uniform (h->range, n, xmin, xmax);
160 
161   /* clear contents */
162 
163   for (i = 0; i < n; i++)
164     {
165       h->bin[i] = 0;
166     }
167 
168   return GSL_SUCCESS;
169 }
170 
171 int
172 gsl_histogram_set_ranges (gsl_histogram * h, const double range[], size_t size)
173 {
174   size_t i;
175   const size_t n = h->n;
176 
177   if (size != (n+1))
178     {
179       GSL_ERROR ("size of range must match size of histogram", GSL_EINVAL);
180     }
181 
182   /* initialize ranges */
183 
184   for (i = 0; i <= n; i++)
185     {
186       h->range[i] = range[i];
187     }
188 
189   /* clear contents */
190 
191   for (i = 0; i < n; i++)
192     {
193       h->bin[i] = 0;
194     }
195 
196   return GSL_SUCCESS;
197 }
198 
199