IGraph/M 0.5

IGraph/M, the Mathematica interface to igraph, just had version 0.5 released.

You will find installation/upgrade instructions here.

New functions

  • IGSplitQ recognizes split graphs and their degree sequences.
  • IGThresholdQ recognizes threshold graphs and their degree sequences.
  • IGPotentiallyConnectedQ recognizes the degree sequences of connected graphs.
  • IGBigraphicalQ recognizes the degree sequence pairs of bipartite graphs.
  • IGEulerianQ tests if a graph has an Eulerian path; IGEulerianPath and IGEulerianPathVertices find it.

Changes to existing functions

  • IGGraphicalQ and IGRealizeDegreeSequence now support some types of non-simple graphs.
  • IGRealizeDegreeSequence now takes arguments in the order indegrees, outdegrees for consistency with other functions (previously it was outdegrees, indegrees).
  • IGEigenvectorCentrality sometimes returned incorrect values for isolated vertices in weighted graphs.
  • IGColoredSimpleGraph no longer discards vertex names.
  • IGModularity now supports directed graphs.
  • IGModularity and IGCommunitiesMultilevel now have a resolution parameter.
  • IGAdjacencyMatrixPlot now allows None to be specified as the colour representing non-existing edges.
  • IGEigenvectorCentrality assumes the adjacency matrix of undirected graphs to have twice the number of self-loops for each vertex on the diagonal. This makes the results consistent between an undirected graph and its directed equivalent when each edge is replaced by a mutual edge pair.


  • IGLayoutReingoldTilford no longer flips the layout.
  • IGLayoutReingoldTilford no longer draws overlapping tree branches.
  • IGBarabasiAlbertGame now allows negative values for β.
  • IGBetweennessEstimate sometimes returned incorrect results with finite cutoffs. This is now corrected.
  • IGCommunitiesLeiden: fix incorrect results when self-loops are present.
  • IGEigenvectorCentrality: fix incorrect results for isolated vertices and for vertices with self-loops.
  • IGGraphicalQ would return incorrect results when the second argument was {}. This is now corrected.

Other changes

  • IGDegreeSequenceGame's "ConfigurationModelSimple" method is now much faster.
  • More robust error handling.


  • IGraph/M 0.5 has been tested with Mathematica 10.3 and later only. Some effort has been made to allow it to work with Mathematica 10.0.2, but it has not been tested and compatibility is not guaranteed.