NEWS

About igraph releases and other things

February 24, 2013

The version number is not a mistake, we jump to 0.6.5 from 0.6, for technical reasons.

Release Notes

igraph 0.6.5 is a minor release that contains only few big changes, and fixes a number of very annoying bugs.

See at the end for the complete list of changes. First let's see the most important new features and changes.

Convert lists of tuples to graphs in Python

The Graph.TupleList() static method in Python now allows easy conversion of lists of tuples (such as database records or contents of CSV files) into graphs with named vertices and edge attributes.

Pajek reader supports bipartite graphs

See more in the documentation.

Graphical degree sequences

We added some new functions if a sequence of integers is graphial, i.e. it can be the degree sequence of a simple graph. See more in the documentation.

k-regular random graphs

It is possible now to generate regular random graphs, faster than the general degree sequence based generator. See more in the documentation.

Fitting power law distributions

This release includes the plfit library to maximum likelihood fit power laws to discrete or contiouous data. See more in the documentation.

Python news and fixes

  • Added bipartite support to the Pajek reader and writer, closes bug #1042298.
  • Graph.Degree_Sequence() has a new method now: no_multiple.
  • Added the is_degree_sequence() and is_graphical_degree_sequence() functions.
  • rewire() has a new mode: loops, that can create loop edges.
  • Walktrap community detection now handles isolates.
  • Added Graph.K_Regular().
  • power_law_fit() now uses a C implementation.
  • Added support for setting the frame (stroke) width of vertices using the frame_width attribute or the vertex_frame_width keyword argument in plot()
  • Improved Inkscape-friendly SVG output from Graph.write_svg(), thanks to drlog
  • Better handling of named vertices in Graph.delete_vertices()
  • Added experimental Gephi graph streaming support; see igraph.remote.gephi and igraph.drawing.graph.GephiGraphStreamingDrawer
  • Nicer __repr__ output for Flow and Cut instances
  • Arrows are now placed correctly around diamond-shaped nodes on plots
  • Added Graph.TupleList, a function that allows one to create graphs with edge attributes quickly from a list of tuples.
  • plot() now also supports .eps as an extension, not only .ps

  • Fixed overflow issues in centralization calculations.

  • Fixed a bug that mishandled vertex colors in VF2 isomorphism functions. Bug #1032819.

  • Pajek exporter now always quotes strings, thanks to Elena Tea Russo.

  • Fixed a bug with handling small edge weights in shortest paths calculation in Graph.shortest_paths() (Dijkstra's algorithm.) Thanks to Martin J Reed.

  • Fixed a bug in the NCV setting for ARPACK functions. It cannot be bigger than the matrix size.

  • Fixed a bug in Graph.layout_mds() that resulted vertices on top of each other.

  • Motif finding functions return nan for isomorphism classes that are not motifs (i.e. not connected). Fixes bug #1050859.

  • Fixed a bug when calculating the largest cliques of a directed graph. Bug #1073800.

  • Warn for negative weights when calculating PageRank.

  • Fixed a bug in Graph.eccentricity() and Graph.radius(), the results were often simply wrong.

  • Fixed a bug in Graph.get.all.shortest.paths() when some edges had zero weight.

  • Fixed some potential crashes in the DrL layout generator.

  • Fixed a bug in the Reingold-Tilford layout when the graph is directed and mode != ALL.

  • Fixed a bug in Graph.layout_sugiyama() when the graph had no edges.

  • Fixed a bug in Graph.community_label_propagation() when initial labels contained -1 entries. Issue #1105460.

  • Repaired the DescartesCoordinateSystem class (which is not used too frequently anyway)

  • Fixed a bug that caused segfaults when an igraph Graph was used in a thread forked from the main Python interpreter thread

  • Fixed a bug that affected file handles created from Python strings in the C layer

  • Fixed a bug in has_multiple() that resulted in false negatives for some undirected graphs.

  • Fixed a crash in weighted betweenness calculation.