[Avida-SVN] r1817 - branches/dkdev/source/main

[dknoester at myxo.css.msu.edu]

Author: dknoester
Date: 2007-07-18 11:08:57 -0400 (Wed, 18 Jul 2007)
New Revision: 1817

Modified:
   branches/dkdev/source/main/cPopulation.cc
Log:
Fixed bug in calculation of clustering coefficient.

Modified: branches/dkdev/source/main/cPopulation.cc
===================================================================
--- branches/dkdev/source/main/cPopulation.cc	2007-07-18 13:50:06 UTC (rev 1816)
+++ branches/dkdev/source/main/cPopulation.cc	2007-07-18 15:08:57 UTC (rev 1817)
@@ -1002,19 +1002,24 @@
           for(; adjacent.first!=adjacent.second; ++adjacent.first) {
             neighbors.insert(*adjacent.first);
           }
-          // Now, count the edges between vertices in the neighborhood.
-          unsigned int neighborhood_edge_count=0;
-          for(neighborhood::iterator i=neighbors.begin(); i!=neighbors.end(); ++i) {
-            typedef cDeme::Network::out_edge_iterator out_edge_iterator;
-            std::pair<out_edge_iterator,out_edge_iterator> oe = out_edges(*i,network);
-            for(; oe.first!=oe.second; ++oe.first) {
-              if(neighbors.find(target(*oe.first,network))!=neighbors.end()) {
-                ++neighborhood_edge_count;
+
+          if(neighbors.size() > 1) {
+            // Now, count the edges between vertices in the neighborhood.
+            unsigned int neighborhood_edge_count=0;
+            for(neighborhood::iterator i=neighbors.begin(); i!=neighbors.end(); ++i) {
+              typedef cDeme::Network::out_edge_iterator out_edge_iterator;
+              std::pair<out_edge_iterator,out_edge_iterator> oe = out_edges(*i,network);
+              for(; oe.first!=oe.second; ++oe.first) {
+                if(neighbors.find(target(*oe.first,network))!=neighbors.end()) {
+                  ++neighborhood_edge_count;
+                }
               }
             }
+            neighborhood_edge_count /= 2;
+            cluster_coeffs.push_back((double)neighborhood_edge_count / (neighbors.size()*(neighbors.size()-1)/2));
+          } else {
+            cluster_coeffs.push_back(1.0);
           }
-          neighborhood_edge_count /= 2;
-          cluster_coeffs.push_back((double)neighborhood_edge_count / (neighbors.size()*(neighbors.size()-1)/2));
         }
         
         // Clustering coefficient: