About igraph releases and other things

December 19, 2006

This is a new major release, it contains many new things: geometric random graphs, local transitivity, etc.

Changes in the C library

  • igraph_maxdegree added, calculates the maximum degree in the graph
  • igraph_grg_game, geometric random graphs
  • igraph_density, graph density calculation
  • push-relabel maximum flow algorithm added, igraph_maxflow_value
  • minimum cut functions added based on maximum flow: igraph_st_mincut_value, igraph_mincut_value, the Stoer-Wagner algorithm is implemented for undirected graphs
  • vertex connectivity functions, usually based on maximum flow: igraph_st_vertex_connectivity, igraph_vertex_connectivity
  • edge connectivity functions, usually based on maximum flow: igraph_st_edge_connectivity, igraph_edge_connectivity
  • other functions based on maximum flow: igraph_edge_disjoint_paths, igraph_vertex_disjoint_paths, igraph_adhesion, igraph_cohesion
  • dimacs file format added
  • igraph_to_directed handles attributes
  • igraph_constraint calculation corrected, it handles weighted graphs
  • spinglass-based community structure detection, the Joerg Reichardt -- Stefan Bornholdt algorithm added: igraph_spinglass_community, igraph_spinglass_my_community
  • igraph_extended_chordal_ring, it creates extended chordal rings
  • no argument added to igraph_clusters, it is possible to calculate the number of clusters without calculating the clusters themselves
  • minimum spanning tree functions keep attributes now and also the direction of the edges is kept in directed graphs
  • there are separate functions to calculate different types of transitivity now
  • igraph_delete_vertices rewritten to allocate less memory for the new graph
  • neighborhood related functions added: igraph_neighborhood, igraph_neighborhood_size, igraph_neighborhood_graphs
  • two new games added based on different node types: igraph_preference_game and igraph_asymmetric_preference_game
  • Laplacian of a graph can be calculated by the igraph_laplacian function

Bugs corrected

  • attribute handling bug when deleting edges corrected
  • GraphML escaping and NaN handling corrected
  • a bug in Erdos-Renyi graph generation corrected: it had problems with generating large directed graphs
  • bug in constraint calculation corrected, it works well now
  • fixed memory leaks in igraph_read_graph_graphml
  • error handling bug corrected in igraph_read_graph_graphml