About igraph releases and other things

R/igraph 0.4

R/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 R interface

  • as the internal representation changed, graphs stored with ‘save’ with an older igraph version cannot be read back with the new version reliably.
  • neighbors returns ordered lists

  • topological sorting
  • VF2 isomorphism algorithm
  • support for reading graphs from the Graph Database for isomorphism
  • 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
  • functions for creating denrdograms from the output of the community detection algorithms added
  • supporting function added, creates a membership vector from a community structure merge tree
  • modularity calculation added

  • graphics parameter handling is completely rewritten, uniform handling of colors and fonts, make sure you read ?igraph.plotting
  • new plotting parameter for edges: arrow.mode
  • a bug corrected when playing a nonlinear
  • better looking plotting in 3d using rglplot: edges are 3d too
  • rglplot layout is allowed to be two dimensional now
  • rglplot suspends updates while drawing, this makes it faster
  • loop edges are correctly plotted by all three plotting functions

  • better printing of attributes when printing graphs
  • summary of a graph prints attribute names
  • is.igraph rewritten to make it possible to inherit from the igraph class
  • somewhat better looking progress meter for functions which support it


  • 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