Looks like I turned an "off my one error" into an "off by two error" by adding rather than subtracting. Clearly a logic error on my part.
Also, which.max is clearly superior as it results in half as many function calls. Thanks guys! As an aside, although igraph may use the C indexing convention, R users and their code, is much more in tune with indexing beginning at 1. Adjusting this in the R interface to igraph may solve many headaches down the road. Mark Mark W. Kimpel MD ** Neuroinformatics ** Dept. of Psychiatry Indiana University School of Medicine 15032 Hunter Court, Westfield, IN 46074 (317) 490-5129 Work, & Mobile & VoiceMail (317) 204-4202 Home (no voice mail please) mwkimpel<at>gmail<dot>com ****************************************************************** Gabor Csardi wrote: > On Wed, Mar 05, 2008 at 02:27:21AM -0500, Charilaos Skiadas wrote: > [...] >> Btw, you will likely want to take the betweenness call out, and call >> it once and store the result, instead of calling it twice (well, >> assuming the graph is largish). Or even better, use which.max: >> >> which.max(betweenness(graph = my.graph, v=V(my.graph), directed = >> FALSE)) > > This is almost good, but there is a catch, in igraph vertices are > numbered from zero. So if you want an igraph vertex id, then you > need to subtract one from this, i.e.: > > maxb <- which.max(betweennness(my.graph, directed=FALSE))-1 > > You can double check it: > > betweenness(my.graph, maxb, directed=FALSE) > > Gabor > > PS. there is also an igraph mailing list, see the igraph homepage > at igraph.sf.net > >> Haris Skiadas >> Department of Mathematics and Computer Science >> Hanover College >> > [...] > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
