Add graph references

2026-06-28 13:49:01 +01:00
parent 0a9807e448
commit a11edf0c53
2578 changed files with 868045 additions and 0 deletions
@@ -0,0 +1,79 @@
+/*
+   igraph library.
+   Copyright (C) 2009-2012  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>
+
+int main(void) {
+
+    igraph_t graph;
+    igraph_real_t cent;
+
+    /* Initialize the library. */
+    igraph_setup();
+
+    /* Create an undirected star graph, which is the most centralized graph
+     * with several common centrality scores. */
+    printf("undirected star graph:\n");
+    igraph_star(&graph, 10, IGRAPH_STAR_UNDIRECTED, /*center=*/ 0);
+
+    igraph_centralization_degree(&graph, /*res=*/ NULL,
+                                 /*mode=*/ IGRAPH_ALL, IGRAPH_NO_LOOPS,
+                                 &cent, /*theoretical_max=*/ NULL,
+                                 /*normalized=*/ true);
+    printf("degree centralization: %g\n", cent);
+
+    igraph_centralization_betweenness(&graph, /*res=*/ NULL,
+                                      IGRAPH_UNDIRECTED, &cent,
+                                      /*theoretical_max=*/ NULL,
+                                      /*normalized=*/ true);
+    printf("betweenness centralization: %g\n", cent);
+
+
+    igraph_centralization_closeness(&graph, /*res=*/ NULL,
+                                    IGRAPH_ALL, &cent,
+                                    /*theoretical_max=*/ NULL,
+                                    /*normalized=*/ true);
+    printf("closeness centralization: %g\n", cent);
+
+    igraph_destroy(&graph);
+
+    /* With eigenvector centrality, the most centralized structure is
+     * a graph containing a single edge. */
+    printf("\ngraph with single edge:\n");
+    igraph_small(&graph, /*n=*/ 10, IGRAPH_UNDIRECTED,
+                 0,1, -1);
+
+    igraph_centralization_eigenvector_centrality(
+                &graph,
+                /*vector=*/ NULL,
+                /*value=*/ NULL,
+                /*mode=*/ IGRAPH_ALL,
+                /*options=*/ NULL,
+                &cent,
+                /*theoretical_max=*/ NULL,
+                /*normalized=*/ true);
+    printf("eigenvector centralization: %g\n", cent);
+
+    igraph_destroy(&graph);
+
+    return 0;
+}