I thought the modularity score is already a comparison to a null model? Best wishes,
Gang Su Bioinformatics PhD candidate Statistics MA University of Michigan, Ann Arbor Michigan 48109 On Thu, Jun 14, 2012 at 3:02 PM, Tamás Nepusz <[email protected]> wrote: >> What exactly is "community significance"? Any literature? --Moses > > Start here, these papers are open access and relatively recent: > > [1] http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0018961 > [2] http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0033721 > > -- > T. >> >> On Thu, Jun 14, 2012 at 9:58 PM, Tamás Nepusz <[email protected] >> (mailto:[email protected])> wrote: >> > Dear Filipe, >> > >> > None of the community significance algorithms are implemented in igraph >> > yet and I am not aware of any such implementations yet. A relatively >> > simple approach is to take each vertex in the community, calculate their >> > internal and external degrees (i.e. the number of edges incident on them >> > that lead inside the community and outside the community, respectively), >> > and then run a Mann-Whitney U-test. The null hypothesis is that the >> > distribution of internal and external degrees is the same (in other words, >> > the community is not a real one because it is just as dense "inside" as >> > "outside"), and the test will reject it if the community is a significant >> > one. I'm sure that there are far better methods than this, but this is >> > relatively easy to implement both in R and in Python using igraph. >> > >> > Best,-- >> > T. >> > >> > >> > On Thursday, 14 June 2012 at 20:55, Filipe Alberto wrote: >> > >> > > Dear list, >> > > >> > > I have been using igraph to detect communities in networks. However, I >> > > would like to use some method to get significance of the derived >> > > communities. I see that there are several algorithms published, but I >> > > don't know if they are available in igraph or if some of the users have >> > > implemented them using R and igraph? >> > > >> > > >> > > Thanks you for your help, >> > > >> > > All the best, >> > > Filipe Alberto >> > > >> > > _______________________________________________ >> > > igraph-help mailing list >> > > [email protected] (mailto:[email protected]) >> > > https://lists.nongnu.org/mailman/listinfo/igraph-help >> > >> > >> > >> > >> > >> > >> > _______________________________________________ >> > igraph-help mailing list >> > [email protected] (mailto:[email protected]) >> > https://lists.nongnu.org/mailman/listinfo/igraph-help >> >> >> >> _______________________________________________ >> igraph-help mailing list >> [email protected] (mailto:[email protected]) >> https://lists.nongnu.org/mailman/listinfo/igraph-help > > > > > _______________________________________________ > igraph-help mailing list > [email protected] > https://lists.nongnu.org/mailman/listinfo/igraph-help _______________________________________________ igraph-help mailing list [email protected] https://lists.nongnu.org/mailman/listinfo/igraph-help
