From 3aee2fd43e3059a699af2b63c6f2395e5a55e515 Mon Sep 17 00:00:00 2001
From: KatolaZ <katolaz@freaknet.org>
Date: Wed, 27 Sep 2017 15:06:31 +0100
Subject: First commit on github -- NetBunch 1.0

---
 src/betweenness/bet_dependency.c | 224 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 224 insertions(+)
 create mode 100644 src/betweenness/bet_dependency.c

(limited to 'src/betweenness/bet_dependency.c')

diff --git a/src/betweenness/bet_dependency.c b/src/betweenness/bet_dependency.c
new file mode 100644
index 0000000..2b55543
--- /dev/null
+++ b/src/betweenness/bet_dependency.c
@@ -0,0 +1,224 @@
+/**
+ *  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 3 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, see
+ *  <http://www.gnu.org/licenses/>.
+ *
+ *  (c) Vincenzo Nicosia 2009-2017 -- <v.nicosia@qmul.ac.uk>
+ * 
+ *  This file is part of NetBunch, a package for complex network
+ *  analysis and modelling. For more information please visit:
+ *
+ *             http://www.complex-networks.net/
+ *
+ *  If you use this software, please add a reference to 
+ *
+ *               V. Latora, V. Nicosia, G. Russo             
+ *   "Complex Networks: Principles, Methods and Applications"
+ *              Cambridge University Press (2017) 
+ *                ISBN: 9781107103184
+ *
+ ***********************************************************************
+ *
+ *  This program computes the betweenness dependency of all the nodes
+ *  of a graph, using Brandes' algorithm, and counting all the
+ *  shortest paths originating from a set of nodes (potentially the
+ *  whole set of vertices).
+ *
+ *  References: 
+ *     U. Brandes. "A Faster Algorithm for Betweenness 
+ *     Centrality". J. Math. Sociol. 25 (2001), 163-177.  
+ *
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "utils.h"
+
+
+void usage(char *argv[]){
+  printf("********************************************************************\n"
+         "**                                                                **\n"
+         "**                  -*-  bet_dependency  -*-                      **\n"
+         "**                                                                **\n"
+         "**  Compute the betweenness dependency of all the nodes of a      **\n"
+         "**  network due to the shortest paths originating from a set      **\n"
+         "**  of initial nodes. If no start node is specified, compute      **\n"
+         "**  the dependency due to all the nodes of the graph. If no end   **\n"
+         "**  node is specified, compute the dependency due to the nodes    **\n"
+         "**  between node_start and the last node of the graph.            **\n"
+         "**                                                                **\n"
+         "**  The dependency of each node is printed on standard output.    **\n"
+         "**                                                                **\n"
+         "**                                                                **\n"
+         "********************************************************************\n"
+         "\n\n"
+         " This is Free Software - You can use and distribute it under \n"
+         " the terms of the GNU General Public License, version 3 or later\n\n"
+         " (c) Vincenzo Nicosia 2009-2017 (katolaz@yahoo.it)\n\n");
+  printf("Usage: %s <graph_in> [<node_start> [<node_end>]]\n\n" , argv[0]);
+}
+
+void add_predecessor(unsigned int **pred, unsigned int k){
+  
+  (*pred)[0] += 1;
+  *pred = realloc(*pred, ((*pred)[0] + 1)  * sizeof(unsigned int));
+  (*pred)[ (*pred)[0] ] = k;
+}
+
+
+
+/*
+ * Returns a list of dependencies
+ */
+double* compute_bet_dependency(unsigned int N, unsigned int *J_slap, unsigned int *r_slap, 
+                                      unsigned int n_start, unsigned int n_end){
+  
+  int i, j, k, w, idx, cur_node;
+  unsigned int  *marked, **preds, *dist, *nj;
+  double  *delta, *cB;
+  unsigned int d;
+  unsigned int n, nd, ndp;
+  
+  dist = malloc(N * sizeof(unsigned int));
+  marked = malloc(N * sizeof(unsigned int));
+  preds = malloc(N * sizeof(unsigned int *));
+  
+  nj = malloc(N * sizeof(unsigned int));
+  delta = malloc(N * sizeof(double));
+  cB = malloc(N * sizeof(double));
+  
+  for (i=0; i<N; i++){
+    cB[i] = 0;
+    preds[i] = NULL;
+  }
+
+  for (j=n_start; j<=n_end && j<N; j++){
+    for(i=0; i<N; i ++){
+      dist[i] = N;
+      if (! preds[i]){
+        preds[i] = malloc(sizeof(unsigned int));
+      }
+      preds[i][0] = 0; /* The list of predecessors is now empty! */
+      
+      nj[i] = 0;
+      delta[i]= 0;
+    }
+    dist[j] = 0;
+    nj[j] = 1;
+    marked[0] = j;
+    d = 0;
+    n = 0;
+    nd = 1;
+    ndp = 0;
+    while (d<N && nd > 0){
+      for(i = n; i< n+nd; i ++){
+        cur_node = marked[i];
+        for (k=r_slap[cur_node]; k<r_slap[cur_node +1] ; k++){
+          w = J_slap[k];
+          if ( dist[w] == d+1){
+            add_predecessor((unsigned int **)(preds + w), cur_node);
+            nj[w] += nj[cur_node];
+          }
+          if ( dist[w] == N){
+            dist[w] = d+1;
+            marked[n + nd + ndp] = w;
+            add_predecessor(preds + w, cur_node);
+            ndp +=1;
+            nj[w] += nj[cur_node];
+          }
+        }
+      }
+      n = n + nd;
+      nd = ndp;
+      ndp = 0;
+      d += 1; 
+    }
+    for (k= n-1; k>=1; k--){
+      w = marked[k];
+      for (idx=1; idx <= preds[w][0]; idx ++ ){
+        i = preds[w][idx];
+        delta[i] += 1.0 * nj[i] / nj[w] * (1 + delta[w]);
+      }
+      cB[w] += delta[w];
+    }
+  }
+  free(dist);
+  free(marked);
+  for (i=0; i<N; i++){
+    free(preds[i]);
+  }
+  free(preds);
+  free(nj);
+  free(delta);
+  
+  return cB;
+}
+
+
+
+void dump_cB(double *cB, unsigned int N){
+
+  unsigned int i;
+  for (i=0; i<N; i++){
+    printf("%g\n", cB[i]);
+  }
+}
+
+
+int main(int argc, char *argv[]){
+  
+  unsigned int *J_slap=NULL, *r_slap=NULL;
+  unsigned int K, N;
+  unsigned int n_start, n_end;
+  double *cB;
+  FILE *filein;
+  
+  n_start = 0;
+  n_end = -1;
+
+  switch (argc){
+
+  case 4:
+    n_end = atoi(argv[3]);
+  case 3:
+    n_start = atoi(argv[2]);
+  case 2:
+    break;
+  default:     
+    usage(argv);
+    exit(1);
+    break;
+  }
+  
+  if (!strcmp(argv[1], "-")){
+    /* take the input from STDIN */
+    filein = stdin;
+  }
+  else {
+    filein = openfile_or_exit(argv[1], "r", 2);
+  }
+
+  read_slap(filein, &K, &N, &J_slap, &r_slap);
+  if (n_end == -1)
+    n_end = N-1;
+  cB = compute_bet_dependency(N, J_slap, r_slap, n_start, n_end);
+  dump_cB(cB, N);
+
+  free(cB);
+  free(J_slap);
+  free(r_slap);
+  
+}
-- 
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