Hello, The bug is triggered by the presence of edges with zero weight. As a workaround, remove the zero-weight edges from the graph before proceeding with the community detection.
-- T. On Wednesday, 25 April 2012 at 20:55, Tamás Nepusz wrote: > Hello, > > Seems to be a bug on our side; I have added a bug report and I am looking > into this right now. You can follow the issue here: > > https://bugs.launchpad.net/igraph/+bug/988480 > > -- > T. > > > On Wednesday, 25 April 2012 at 18:00, R N wrote: > > > Hello, > > > > I'm using igraph-0.6 build 2694-20120421. I'm trying to use the edge > > betweenness community detection > > function with weighted graphs. I tried out a couple of graphs that I > > have, with 1000 vertices and ~2200 edges. > > The function crashes on both of them if edge weights are used, but > > works if the edge weights are not used. > > It seems that it crashes at line 866 of file 'heap.c', in function > > 'igraph_i_2wheap_switch'. > > Is there some (hopefully small) error in igraph or my negligence in using > > it? > > > > Here are the crashy graphs: > > http://www.sendspace.com/filegroup/WXCyAHR%2F28xEv21G0LQm8A > > > > And here is the full proggy that I used. > > > > ---8<--- > > > > #include <igraph.h> > > #include <string.h> > > #include <stdlib.h> > > > > int cd_edge_betweenness (igraph_t *g, igraph_vector_t *weights, > > igraph_vector_t *cm, double *Q) > > { > > > > igraph_vector_t modularity_eb; > > igraph_vector_t eb, edges; > > > > igraph_vector_init (&modularity_eb, 0); > > igraph_vector_init (&eb, 0); > > igraph_vector_init (&edges, 0); > > > > igraph_community_edge_betweenness( > > g, > > &edges, > > &eb, > > 0, // merges > > 0, // bridges > > &modularity_eb, // modularity > > cm, //membership > > IGRAPH_UNDIRECTED, > > weights); > > > > long int i_eb_max_mod = igraph_vector_which_max (&modularity_eb); > > *Q = VECTOR (modularity_eb)[i_eb_max_mod]; > > > > igraph_vector_destroy (&modularity_eb); > > igraph_vector_destroy (&eb); > > igraph_vector_destroy (&edges); > > > > return 0; > > } > > > > int main(int argc, char *argv[]) > > { > > > > igraph_t g; > > FILE *ifile, *ofile; > > long int i; > > long int num_vertex, num_edge; > > double Q; > > > > igraph_vector_t gtypes, vtypes, etypes; > > igraph_strvector_t gnames, vnames, enames; > > > > if (argc < 3) > > { > > printf ("Usage: %s (IN)in.graphml (OUT)comm_membership_file\n", argv[0]); > > return -1; > > } > > > > ifile=fopen(argv[1], "r"); > > if (ifile == 0) > > { > > printf ("File opening error: %s\n", argv[1]); > > return -1; > > } > > > > ofile = fopen (argv[2], "w"); > > if (ofile == 0) > > { > > printf ("File opening error: %s\n", argv[2]); > > return -1; > > } > > > > igraph_i_set_attribute_table(&igraph_cattribute_table); > > igraph_read_graph_graphml (&g, ifile, 0); > > fclose(ifile); > > > > igraph_vector_init(>ypes, 0); > > igraph_vector_init(&vtypes, 0); > > igraph_vector_init(&etypes, 0); > > igraph_strvector_init(&gnames, 0); > > igraph_strvector_init(&vnames, 0); > > igraph_strvector_init(&enames, 0); > > > > igraph_cattribute_list(&g, &gnames, >ypes, &vnames, &vtypes, > > &enames, &etypes); > > > > num_vertex = igraph_vcount (&g); > > num_edge = igraph_ecount (&g); > > > > igraph_vector_t weights; > > igraph_vector_t cm; // community membership vector > > > > igraph_vector_init (&weights, num_edge); > > igraph_vector_init (&cm, num_vertex); > > > > for (i=0; i < num_edge; i++) > > { > > //printf ("%d: Edge id=%s, weight=%f\n", i, EAS (g, "id", i), EAN > > (g, "weight", i)); > > VECTOR(weights) [i] = EAN (&g, "weight", i); > > } > > > > int ires = cd_edge_betweenness (&g, &weights, &cm, &Q); > > > > fprintf (ofile, "# modularity: Q=%g\n", Q); > > for (i = 0; i < num_vertex; ++i) > > { > > fprintf (ofile, "%d\t", (int) VECTOR (cm) [i]); > > } > > fprintf (ofile, "\n"); > > > > igraph_vector_destroy (&weights); > > igraph_vector_destroy (&cm); > > > > igraph_vector_destroy (>ypes); > > igraph_vector_destroy (&vtypes); > > igraph_vector_destroy (&etypes); > > igraph_strvector_destroy (&gnames); > > igraph_strvector_destroy (&vnames); > > igraph_strvector_destroy (&enames); > > > > igraph_destroy(&g); > > > > return 0; > > } > > > > _______________________________________________ > > igraph-help mailing list > > igraph-help@nongnu.org (mailto:igraph-help@nongnu.org) > > https://lists.nongnu.org/mailman/listinfo/igraph-help > _______________________________________________ igraph-help mailing list igraph-help@nongnu.org https://lists.nongnu.org/mailman/listinfo/igraph-help
