Actually, library(igraph)
tab <- read.csv("http://www.nabble.com/file/p22957493/sp_matrix.csv") tab <- tab[,-1] g <- graph.adjacency(as.matrix(tab), weighted=TRUE) V(g)$label <- V(g)$name mst <- as.undirected(minimum.spanning.tree(g)) lay <- layout.reingold.tilford(mst, root=which.max(degree(mst))-1) lay <- cbind(lay[,2], lay[,1]) # rotate x11(width=15, height=8) plot(mst, layout=lay, vertex.size=25, vertex.size2=10, vertex.shape="rectangle", asp=FALSE, vertex.label.cex=0.7, vertex.color="white") works relatively well for me on your graph. It doesn't for you? Best, Gabor On Wed, Apr 8, 2009 at 9:14 PM, jpearl01 <joshea...@hotmail.com> wrote: > > > Make the graph undirected first and then choose the right plotting > parameters. E.g. the following works fine for me: > > set.seed(2) > g <- erdos.renyi.game(100, 300, type="gnm", directed=TRUE) > E(g)$weight <- runif(ecount(g)) > mst <- minimum.spanning.tree(g) > > mst <- simplify(as.undirected(mst)) > lay <- layout.reingold.tilford(mst, root=which.max(degree(mst))-1) > plot(mst, layout=lay, vertex.size=5, asp=FALSE, vertex.color=NA, > vertex.frame.color=NA) > > G. > > > Thanks for all your help Gabor, However, I'm unable to get a display in R > which is at all readable. I'm not sure why that is (if the data is > generated randomly, like in your example the tree builds/reads fine... > however on my dataset whichever node is picked as the root just completely > over powers the rest of the nodes which all clump together in a manner that > is unreadable). My dataset is: > http://www.nabble.com/file/p22957493/sp_matrix.csv sp_matrix.csv > If you would like to take a look. However, as it stands I think I'll have > to find another option. Thanks again for all your efforts. > > ~josh > -- > View this message in context: > http://www.nabble.com/Minimum-Spanning-Tree-tp22934813p22957493.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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. > -- Gabor Csardi <gabor.csa...@unil.ch> UNIL DGM ______________________________________________ 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.