About igraph releases and other things

C/igraph 0.4

C/igraph 0.4

May 21, 2007

The major new additions in this release is a bunch of community detection algorithms and support for the GML file format. Here is the complete list of changes:

New in the C library

  • internal representation changed
  • igraph_neighbors always returns an ordered list
  • igraph_is_loop and igraph_is_multiple added

  • topological sorting
  • VF2 isomorphism algorithm
  • support for reading the file format of the Graph Database for isomorphism
  • igraph_mincut cat calculate the actual minimum cut
  • girth calculation added, thanks to Keith Briggs
  • support for reading and writing GML files

  • Walktrap community detection algorithm added, thanks to Matthieu Latapy and Pascal Pons
  • edge betweenness based community detection algorithm added
  • fast greedy algorithm for community detection by Clauset et al. added thanks to Aaron Clauset for sharing his code
  • leading eigenvector community detection algorithm by Mark Newman added
  • igraph_community_to_membership supporting function added, creates a membership vector from a community structure merge tree
  • modularity calculation added


  • proper support for Debian packages (re)added
  • many functions benefit from the new internal representation and are faster now: transitivity, reciprocity, graph operator functions like intersection and union, etc.
  • igraph compiles with Microsoft Visual C++ now
  • there were some internal changes to make igraph a real graph algorithm platform in the near future, but these are undocumented now

Bugs corrected

  • corrected a bug when reading Pajek files: directed graphs were read as undirected