From: Gabor Csardi <csardi_at_rmki.kfki.hu>

Date: Wed, 20 Feb 2008 21:11:10 +0100

Date: Wed, 20 Feb 2008 21:11:10 +0100

igraph is a package for graphs and networks. It has a C core and
uses a simple and fast graph representation allowing millions
of vertices and edges.

**NEW FEATURES:
**

- We use the ARPACK library for graph related eigenvalue problems, like Page Rank calculation, Kleinberg's hub and authority scores, eigenvector centrality, etc. There is also a generic interface if someone wants to use ARPACK for a different (not necessarily graph-related) problem.
- We support the BLISS graph isomorphism algorithm, and the implementation of the VF2 algorithm can calculate subgraph isomorphisms now.
- We include a collection of "famous" graphs, these can be created by referring to their name.
- We have a new 'graph.formula' function, for creating small graphs using symbolic names, by giving simple R formulae.
- Many functions support weighted graphs now: Page Rank, modularity calculation, the fast greedy community finding algorithm, etc.
- We have a new graph layout algorithm called 'graphopt'.
- A bunch of new functions are added: biconnected components and articulation points, dyad and triad census, functions for vertex similarity, functions for estimating closeness, betweenness and edge betweenness, etc.
- igraph can write files in the DOT format now.
- Some graphics improvements, e.g. it is possible to draw graphs on top of each other, etc.
- Many bugs were fixed, the most important one is probably that now memory is always properly deallocated when CTRL+C (ESC) is used to interrupt a computation.

**PACKAGE DESCRIPTION:
**
igraph is originally a C library for graphs, but has interfaces
to high level languages like R, Python and Ruby. The R package
contains BOTH the C library and its R interface.

igraph supports:

- graph generators, creating both regular structures like trees, lattices, etc. and various random graphs.
- a rich set of functions calculating structural properties of graphs, like vertex centrality (degree, betweenness, closeness, page rank, eigenvector centrality, Burt's constraints, etc.), shortest paths, dyad and triad census, network motifs, girth, K-core decomposition, etc.
- attributes can be associated with the vertices/edges of the graph, or the graph itself. The attributes can be arbitrary R objects.
- graph visualization using regular R devices, interactive visualization using Tcl/Tk, 3D visualization using RGL.
- graph layout generators, the standard Kamada-Kawai and Fruchterman-Reingold algorithms are included, plus many more.
- Functions for graph and subgraph isomorphism, the BLISS and the VF2 algorithms are included.
- Functions for maximal network flows, minimal cuts, vertex and edge connectivity.
- igraph can read and write many popular file formats used for storing graph data: GraphML, Pajek, GML and others.
- igraph contains implementations of many community structure detection algorithms proposed recently.

See more at the igraph homepage:

http://cneurocvs.rmki.kfki.hu/igraph/index.html

-- Csardi Gabor <csardi_at_rmki.kfki.hu> _______________________________________________ R-packages mailing list R-packages_at_r-project.org https://stat.ethz.ch/mailman/listinfo/r-packagesReceived on Thu 21 Feb 2008 - 07:26:23 EST

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