using graph.adjacency() in R

Question

I have a sample code in R as follows:

library(igraph)
rm(list=ls())
dat=read.csv(file.choose(),header=TRUE,row.names=1,check.names=T) # read .csv file
m=as.m         


        

Answer 1

The problem seems to be due to the data-type of the matrix elements. graph.adjacency expects elements of type numeric. Not sure if its a bug.

After you do,

m <- as.matrix(dat)

set its mode to numeric by:

mode(m) <- "numeric"

And then do:

net <- graph.adjacency(m, mode = "undirected", weighted = TRUE, diag = FALSE)
> E(net)$weight
[1]  8  1 10  1 15  1  1  5  7  1