search for: adjmatrix

...e unexpected results from some functions of igraph and it is possible that I am misinterpreting the vertex numbers. Eg., the max betweenness measure seems to be from a vertex that is not connected to a single other vertex. Below if my code snippet: require(igraph) my.graph <- graph.adjacency(adjmatrix = my.adj.matrix, mode=c("undirected")) most.between.vert <- colnames(my.adj.matrix)[which(betweenness(graph = my.graph, v=V(my.graph), directed = FALSE) == max(betweenness(graph = my.graph, v=V(my.graph), directed = FALSE))) + 1] sum(my.adj.matrix[most.between.vertext,]) 0 Is the...

....csv",sep=",",skip=1) arr=array(0,dim=c(4,4)) a<-1 while(a<=length(matrixmy)) { i=matrixmy[a] a<-a+1 j=matrixmy[a] a<-a+1 k=matrixmy[a] arr[i,j]<-k arr[j,i]<-k a<-a+1 } Created matrix mat1<-matrix(data=arr,nrow=4,ncol=4) g<-graph.adjacency(adjmatrix=mat1,mode=c("undirected")) betweenness(g) The answer I get is 0 0 0 0 I was expecting Node 1 will have high value. Can someone tell me why it is happening like this. Thanks in advance. Nathna -- View this message in context: http://www.nabble.com/Weighted-Graph-Link-strength-%...

...rbind,mat_adj) Error in do.call(rbind, mat_adj) : object 'mat_adj' not found > library(igraph) Attaching package: ?igraph? The following object(s) are masked from ?package:R.oo?: hierarchy > g<-graph.adjacency(adj, mode=c("directed"), weighted=T) Error in inherits(adjmatrix, "Matrix") : object 'adj' not found

I have created an adjacency matrix but have not been able to figure something out. I need to put zeros on the diagonal of the adjacency matrix. For instance, location (i,i) to equal 0. Please help. Thanks -- View this message in context: http://r.789695.n4.nabble.com/Adjacency-Matrix-help-tp3740946p3740946.html Sent from the R help mailing list archive at Nabble.com.

Hi all, I'm very new to R and read a few tutorials, however I'm having difficulty trying to figure out how to plot a minimum spanning tree. I have a csv file that contains an n-by-n matrix of distances between strains of bacteria called matrix.csv. Looks like: id,strain1, strain2,strain3 strain1,0,.2,.8 strain2,.3,0,.7 strain3,.4,.6,0 I've been messing around with some information