GRASS GIS 8 Programmer's Manual 8.4.1(2025)-45ca3179ab
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c_begin.c
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1/*!
2 \file cluster/c_begin.c
3
4 \brief Cluster library - Begin clusterring
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 <stdlib.h>
15#include <grass/glocale.h>
16#include <grass/cluster.h>
17
18/*!
19 \brief Initialize the cluster routines for nbands
20
21 \param C pointer to Cluster structure
22 \param nbands number of bands
23
24 \return 0 ok
25 \return -1 out of memory
26 \return 1 illegal number of bands
27 */
28int I_cluster_begin(struct Cluster *C, int nbands)
29{
30 int band;
31
32 if (C->points != NULL) {
33 for (band = 0; band < C->nbands; band++)
34 if (C->points[band] != NULL)
35 free(C->points[band]);
36 free(C->points);
37 }
38 if (C->band_sum != NULL)
39 free(C->band_sum);
40 if (C->band_sum2 != NULL)
41 free(C->band_sum2);
42
43 C->points = NULL;
44 C->band_sum = NULL;
45 C->band_sum2 = NULL;
46
47 I_free_signatures(&C->S);
48
49 /* record the number of bands */
50 C->nbands = nbands;
51 if (nbands <= 0)
52 return 1;
53
54 /* prepare the signatures for nbands */
55
56 I_init_signatures(&C->S, nbands);
57 sprintf(C->S.title, _("produced by i.cluster"));
58
59 /* allocate the data (points) arrays */
60 C->points = (DCELL **)malloc(C->nbands * sizeof(DCELL *));
61 if (C->points == NULL)
62 return -1;
63 for (band = 0; band < C->nbands; band++)
64 C->points[band] = NULL;
65
66 C->np = 128;
67 for (band = 0; band < C->nbands; band++) {
68 C->points[band] = (DCELL *)malloc(C->np * sizeof(DCELL));
69 if (C->points[band] == NULL)
70 return -1;
71 }
72
73 /* initialize the count to zero */
74 C->npoints = 0;
75
76 /* allocate the band sums and means */
77 C->band_sum = (double *)malloc(C->nbands * sizeof(double));
78 if (C->band_sum == NULL)
79 return -1;
80 C->band_sum2 = (double *)malloc(C->nbands * sizeof(double));
81 if (C->band_sum2 == NULL)
82 return -1;
83 for (band = 0; band < C->nbands; band++) {
84 C->band_sum[band] = 0;
85 C->band_sum2[band] = 0;
86 }
87
88 return 0;
89}
int I_cluster_begin(struct Cluster *C, int nbands)
Initialize the cluster routines for nbands.
Definition c_begin.c:28
#define NULL
Definition ccmath.h:32