First commit on github -- NetBunch 1.0

1 files changed, 130 insertions, 0 deletions

diff --git a/src/graph_info/graph_info.c b/src/graph_info/graph_info.c
new file mode 100644
index 0000000..3fc0ec6
--- /dev/null
+++ b/src/graph_info/graph_info.c
@@ -0,0 +1,130 @@
+/**
+ *  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
+ *
+ ***********************************************************************
+ *
+ *  Compute and print the basic properties of the undirected graph on
+ *  input, i.e., the number of nodes, the number of edges, and the
+ *  first two uncentered moments of the degree sequence (<k> and
+ *  <k^2>).
+ * 
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "utils.h"
+
+
+void usage(char *argv[]){
+
+    printf("********************************************************************\n"
+         "**                                                                **\n"
+         "**                        -*- graph_info -*-                      **\n"
+         "**                                                                **\n"
+         "**  Compute basic information about the 'graph_in', namely the    **\n"
+         "**  number of nodes, number of edges, average degree, and the     **\n"
+         "**  average squared degree.                                        **\n"
+         "**                                                                **\n"
+         "**   The input file 'graph_in' is an edge-list:                   **\n"
+         "**                                                                **\n"
+         "**                            I_1 J_1                             **\n"
+         "**                            I_2 J_2                             **\n"
+         "**                            I_3 J_3                             **\n"
+         "**                            ... ...                             **\n"
+         "**                            I_K J_K                             **\n"
+         "**                                                                **\n"
+         "**    If 'graph_in' is equal to '-' (dash), read the file from    **\n" 
+         "**    the standard input (STDIN).                                 **\n"
+         "**                                                                **\n"
+         "**    The output is a single line containing in the format:       **\n"
+         "**                                                                **\n"
+         "**       N K avg_k avg_k2                                         **\n"
+         "**                                                                **\n"
+         "**    where 'N' is the number of nodes, 'K' is the number of      **\n"
+         "**    edges, 'avg_k' is the average degree, and 'avg_k2' is the   **\n"
+         "**    average of the squared degree.                              **\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"
+         " Please visit http://www.complex-networks.net for more information\n\n"
+         " (c) Vincenzo Nicosia 2009-2017 (v.nicosia@qmul.ac.uk)\n"
+         "********************************************************************\n\n"
+         );
+  printf("Usage: %s <graph_in>\n", argv[0]);
+}
+
+
+
+double ksquare_mean(unsigned int N, unsigned int *r_slap){
+  
+  double sum = 0;
+  unsigned int i;
+  unsigned int k;
+  for(i=0; i<N; i++){
+    k = r_slap[i+1] - r_slap[i];
+    sum += k*k;
+  }
+  sum /= N;
+  return sum;
+}
+
+
+int main(int argc, char *argv[]){
+  
+  unsigned int N, K;
+  unsigned int *J_slap, *r_slap;
+  FILE *filein;
+  double k2mean;
+
+  if(argc < 2){
+    usage(argv);
+    exit(1);
+  }
+  
+  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);
+
+  fclose(filein);
+  
+  k2mean = ksquare_mean(N, r_slap);
+  printf("%d %d %2.6f %2.6f\n", N, K/2, 1.0*K / N, k2mean);
+  free(J_slap);
+  free(r_slap);
+  
+}