I don't know why I can't use R script for igraph any more that worked before. I would really appreciate it if you could help me with this. The script I used here is:
library(igraph)
matrix1<-as.matrix(data)
matrix1
     var1 var2 var3 var4 var5 var6 var7 var8
[1,] 1.00 0.04 0.21 0.39 0.06 0.37 0.03 0.44
[2,] 0.04 1.00 0.34 0.36 0.63 0.25 0.66 0.18
[3,] 0.21 0.34 1.00 0.44 0.41 0.57 0.72 0.62
[4,] 0.39 0.36 0.44 1.00 0.28 0.14 0.51 0.10
[5,] 0.06 0.63 0.41 0.28 1.00 0.50 0.73 0.39
[6,] 0.37 0.25 0.57 0.14 0.50 1.00 0.50 0.65
[7,] 0.03 0.66 0.72 0.51 0.73 0.50 1.00 0.52
[8,] 0.44 0.18 0.62 0.10 0.39 0.65 0.50 1.00
graph.adjacency(matrix1,mode='undirected',weighted=TRUE)
"then I get error message below"
Error in d[i, ] : incorrect number of dimensions Warning: stack imbalance in '.Call', 51 then 50
More information below:
> str(matrix1)
 num [1:8, 1:8] 1 0.04 0.21 0.39 0.06 0.37 0.03 0.44 0.04 1 ...
 - attr(*, "dimnames")=List of 2
  ..$ : NULL
  ..$ : chr [1:8] "var1" "var2" "var3" "var4" ...
> sessionInfo()
R version 3.0.2 (2013-09-25)
Platform: x86_64-w64-mingw32/x64 (64-bit)
locale:
[1] LC_COLLATE=English_Australia.1252  LC_CTYPE=English_Australia.1252   
[3] LC_MONETARY=English_Australia.1252 LC_NUMERIC=C                      
[5] LC_TIME=English_Australia.1252    
attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     
other attached packages:
[1] igraph_0.6.5-2
loaded via a namespace (and not attached):
 [1] colorspace_1.2-4   dichromat_2.0-0    digest_0.6.3       ggplot2_0.9.3.1   
 [5] grid_3.0.2         gtable_0.1.2       labeling_0.2       lattice_0.20-23   
 [9] MASS_7.3-29        Matrix_1.0-14      mgcv_1.7-26        munsell_0.4.2     
[13] nlme_3.1-111       plyr_1.8           proto_0.3-10       RColorBrewer_1.0-5
[17] reshape2_1.2.2     scales_0.2.3       stringr_0.6.2      tools_3.0.2    
> traceback()
4: c(list(), list(logical(0)))
3: .Call("R_igraph_weighted_adjacency", adjmatrix, as.numeric(mode), 
       weighted, diag, PACKAGE = "igraph")
2: graph.adjacency.dense(adjmatrix, mode = mode, weighted = weighted, 
       diag = diag)
1: graph.adjacency(matrix1, mode = "undirected", weighted = TRUE)
Thanks!
 
    