[igraph] Betweenness in weighted adjacency matrix

[Antoniazzi Marco]

I have recently generated the following code to perform a social network analysis with R in igraph. I am not sure whether the results are correct because I don't know how to check using other programs. Any help is appreciated! thanks. here is the code:

Import the txt file which looks as following (The first row specifies the code for the different nodes, the other rows specifies the weights of edges).

'A','B','C','D','E','F','G','H',

0,0,5,0,0,0,4,0,4,8,2,1,5

0,0,4,0,0,0,0,0,1,0,1,0,0

5,3,0,0,10,2,7,1,0,4,3,10,3

2,0,1,0,6,0,2,4,2,1,3,0,5

2,0,10,5,0,2,8,2,4,0,4,3,3

0,2,2,0,1,0,5,0,1,0,1,1,1

2,0,8,3,9,1,0,2,5,1,5,10,11

1,1,7,2,4,1,1,0,1,0,3,0,1

Once imported I want to transform it in an adjacency matrix taking into consideration the direction of communication and the weights.

ABC = read.table (filename, header = TRUE, sep = ",")
n <- as.matrix ( ABC )
ng <- graph.adjacency ( n, weighted = TRUE )
betw <- betweenness ( ng, directed = TRUE, weights = E ( ng )$weight )

IS it ok for igraph to have the name of the nodes just in the first row and not in the first column to generate an adjacency matrix? i have read somewhere it is the same as having the first column with 'A','B','C',etc

I want then to calculate the betweenness, that will return a result for each node, but I am not sure whether the weights are inserted correctly in the function. Can somebody pls help?

Is there a way I can check the results using other programs?

Thanks!