C/igraph 0.9.4

C/igraph 0.9.4 is now released. This is likely to be the last release of the 0.9.x series, with development efforts shifting to 0.10.

As usual, the source code can be obtained from the GitHub releases page.

igraph is also included in many package managers and Linux distros. To see if your favourite package manager has the latest version, check igraph package versions - Repology

Additionally, now a Dash docset is available for C/igraph. It can be viewed with documentation browsers such as Dash, Zeal, Velocity or Emacs Helm-Dash. This is provided for convenience. As before, the latest version of the documentation is available on the website, and version-specific documentation is included in the source tarballs.


  • Unweighted transitivity (i.e. clustering coefficient) calculations now ignore multi-edges and edge directions instead of rejecting multigraphs and directed graphs.
  • igraph_transitivity_barrat() now returns an error code if the input graph has multiple edges (which is not handled correctly by the implementation yet).


  • igraph_local_scan_k_ecount() now handles loops correctly.
  • igraph_transitivity_avglocal_undirected() is no longer slower than igraph_transitivity_local_undirected().
  • Worked around an invalid warning issued by Clang 9.0 when compiling with OpenMP.


  • Documentation improvements.