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[igraph] betweeness centrality for a directed weighted graph
From: |
Jonas Richhardt |
Subject: |
[igraph] betweeness centrality for a directed weighted graph |
Date: |
Wed, 02 Jul 2014 11:56:50 +0200 |
User-agent: |
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 |
Hi,
Fist of all I use the igraph package in R.
I struggle with the betweeness centrality funciton. First question is
does that function resbects the weights of a graph.
I think it does not. If i use the general formula to calculate the
betweeness centrality with the betweeness for the single knotes my
results differ form what the
betweeness centrality function returns.
#### begin code
patchmat =
cbind(c(0,0,0,0,0,1),c(0,0,1,0,0,0),c(0,1,0,0,0,1),c(0,0,0,0,1,1),c(0,0,0,1,0,1),c(1,0,1,1,1,0))
for (row in seq (1:6)){ ### some sort of normalising
patchmat[row,] <- dat.raw[row,]/sum(dat.raw[row,])
patchmat = matrix(data = patchmat, ncol = 6, nrow = 6)
}
graph <- graph.adjacency(as.matrix(patchmat), mode="directed",
weighted=TRUE) ### here we transform the adjacency
matrix into a graph-object
betweenness(graph, v=V(graph), directed = TRUE, normalized = TRUE) ###
returns 0.72
### but using the general formula
6*max(betweenness(graph, v=V(graph), directed = TRUE, normalized =
TRUE))-sum(betweenness(graph, v=V(graph), directed = TRUE, normalized =
TRUE)) ### returns 3.6
#### end code
Please help me to understand what happens here. The results differ by a
factor of 5.
Thanks in review
Jonas
- [igraph] betweeness centrality for a directed weighted graph,
Jonas Richhardt <=