GRASS GIS 7 Programmer's Manual  7.7.svn(2018)-r73679
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c_distinct.c
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1 /*!
2  \file cluster/c_distinct.c
3 
4  \brief Cluster library - Distinct value
5 
6  (C) 2001-2009 by the GRASS Development Team
7 
8  This program is free software under the GNU General Public License
9  (>=v2). Read the file COPYING that comes with GRASS for details.
10 
11  \author Original author CERL
12 */
13 
14 #include <grass/cluster.h>
15 
16 /*!
17  \brief Get distinct value
18 
19  \param C pointer to Cluster structure
20  \param separation separation value
21 
22  \return distinction value
23 */
24 int I_cluster_distinct(struct Cluster *C, double separation)
25 {
26  int class1, class2;
27  int distinct;
28  double dmin;
29  double dsep;
30 
31  /* compute sum of squares for each class */
32  I_cluster_sum2(C);
33 
34  /* find closest classes */
35  distinct = 1;
36  dmin = separation;
37  for (class1 = 0; class1 < (C->nclasses - 1); class1++) {
38  if (C->count[class1] < 2)
39  continue;
40  for (class2 = class1 + 1; class2 < C->nclasses; class2++) {
41  if (C->count[class2] < 2)
42  continue;
43  dsep = I_cluster_separation(C, class1, class2);
44 
45  if (dsep >= 0.0 && dsep < dmin) {
46  distinct = 0;
47  C->merge1 = class1;
48  C->merge2 = class2;
49  dmin = dsep;
50  }
51  }
52  }
53 
54  return distinct;
55 }
int merge1
Definition: cluster.h:28
int nclasses
Definition: cluster.h:27
Definition: cluster.h:7
int * count
Definition: cluster.h:19
int I_cluster_sum2(struct Cluster *C)
Compute sum of squares for each class.
Definition: c_sum2.c:23
double I_cluster_separation(struct Cluster *C, int class1, int class2)
?
Definition: c_sep.c:26
int merge2
Definition: cluster.h:28
int I_cluster_distinct(struct Cluster *C, double separation)
Get distinct value.
Definition: c_distinct.c:24