[Using igraph ‘0.6.5.1’ under R] I noticed that cohesive blocks (with cohesion equal to 2) and biconnected components of a graph might differ (to my knowledge, they should be the same). Here's an example:
# Load Newman's network science collaboration graph # (http://www-personal.umich.edu/~mejn/netdata/netscience.zip) g = read.graph(file="netscience.gml", format="gml") # Get the giant component of the graph cl = clusters(g) g = induced.subgraph(g, which(cl$membership == which.max(cl$csize))) # Get cohesive blocks cb = cohesive.blocks(g) b = blocks(cb) # Get the largest cohesive block with cohesion 2 (number 69, should be the largest biconnected component) g1 = induced.subgraph(g, b[[69]]) # Get biconnected components bc = biconnected.components(g) c = bc$components # Get the largest biconnected component (number 86) g2 = induced.subgraph(g, c[[86]]) > graph.cohesion(g1) [1] 2 > graph.cohesion(g2) [1] 2 Now, g1 and g2 should be the same graph, but: > g1 IGRAPH U--- 56 171 -- + attr: id (v/n), label (v/c), value (e/n) > g2 IGRAPH U--- 134 372 -- + attr: id (v/n), label (v/c), value (e/n) Thanks, Massimo Franceschet _______________________________________________ igraph-help mailing list [email protected] https://lists.nongnu.org/mailman/listinfo/igraph-help
