1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
|
/* -*- mode: C -*- */
/*
IGraph library.
Copyright (C) 2006-2013 Gabor Csardi <csardi.gabor@gmail.com>
334 Harvard street, Cambridge, MA 02139 USA
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
*/
#include <igraph.h>
void test_density(const igraph_t *graph, igraph_bool_t loops) {
igraph_real_t density;
if (igraph_density(graph, &density, loops)) {
printf("FAILED!\n");
return;
}
if (igraph_is_nan(density)) {
printf("nan\n");
} else {
printf("%.4f\n", density);
}
}
int main() {
igraph_t g;
igraph_vector_t v;
igraph_vector_init(&v, 0);
/* Test graphs with no vertices and no edges */
igraph_create(&g, &v, 0, IGRAPH_UNDIRECTED);
test_density(&g, 0); test_density(&g, 1);
igraph_destroy(&g);
igraph_create(&g, &v, 0, IGRAPH_DIRECTED);
test_density(&g, 0); test_density(&g, 1);
igraph_destroy(&g);
printf("======\n");
/* Test graphs with one vertex and no edges */
igraph_create(&g, &v, 1, IGRAPH_UNDIRECTED);
test_density(&g, 0); test_density(&g, 1);
igraph_destroy(&g);
igraph_create(&g, &v, 1, IGRAPH_DIRECTED);
test_density(&g, 0); test_density(&g, 1);
igraph_destroy(&g);
printf("======\n");
/* Test graphs with one vertex and a loop edge */
igraph_vector_resize(&v, 2);
VECTOR(v)[0] = 0; VECTOR(v)[1] = 0;
igraph_create(&g, &v, 1, IGRAPH_UNDIRECTED);
test_density(&g, 1);
igraph_destroy(&g);
igraph_create(&g, &v, 1, IGRAPH_DIRECTED);
test_density(&g, 1);
igraph_destroy(&g);
printf("======\n");
/* Test graphs with one vertex and two loop edges */
igraph_vector_resize(&v, 4);
VECTOR(v)[0] = 0; VECTOR(v)[1] = 0;
VECTOR(v)[2] = 0; VECTOR(v)[3] = 0;
igraph_create(&g, &v, 1, IGRAPH_UNDIRECTED);
test_density(&g, 1);
igraph_destroy(&g);
igraph_create(&g, &v, 1, IGRAPH_DIRECTED);
test_density(&g, 1);
igraph_destroy(&g);
printf("======\n");
/* Test graphs with two vertices and one edge between them */
igraph_vector_resize(&v, 2);
VECTOR(v)[0] = 0; VECTOR(v)[1] = 1;
igraph_create(&g, &v, 2, IGRAPH_UNDIRECTED);
test_density(&g, 0); test_density(&g, 1);
igraph_destroy(&g);
igraph_create(&g, &v, 1, IGRAPH_DIRECTED);
test_density(&g, 0); test_density(&g, 1);
igraph_destroy(&g);
printf("======\n");
/* Test graphs with two vertices, one edge between them and a loop on one
* of them */
igraph_vector_resize(&v, 4);
VECTOR(v)[0] = 0; VECTOR(v)[1] = 1;
VECTOR(v)[2] = 1; VECTOR(v)[3] = 1;
igraph_create(&g, &v, 2, IGRAPH_UNDIRECTED);
test_density(&g, 1);
igraph_destroy(&g);
igraph_create(&g, &v, 1, IGRAPH_DIRECTED);
test_density(&g, 1);
igraph_destroy(&g);
printf("======\n");
/* Test graphs with two vertices, one edge between them and a loop on both
* of them */
igraph_vector_resize(&v, 6);
VECTOR(v)[0] = 0; VECTOR(v)[1] = 1;
VECTOR(v)[2] = 1; VECTOR(v)[3] = 1;
VECTOR(v)[4] = 0; VECTOR(v)[5] = 0;
igraph_create(&g, &v, 2, IGRAPH_UNDIRECTED);
test_density(&g, 1);
igraph_destroy(&g);
igraph_create(&g, &v, 1, IGRAPH_DIRECTED);
test_density(&g, 1);
igraph_destroy(&g);
printf("======\n");
/* Zachary karate club graph */
igraph_famous(&g, "zachary");
test_density(&g, 0); test_density(&g, 1);
igraph_destroy(&g);
igraph_vector_destroy(&v);
}
|
