[igraph] Saving in Pajek with colors with igraph

[Richard O. Legendi]

Hi all,

I'm trying to figure out how do I save a simple graph in Pajek with 
defined color values. When I try it, I get the following error message:

        > g <- graph.ring(10)
        > V(g)$color <- "red"
        > write.graph(g, format="pajek", file="C:\\tmp\\test.net")
        Error in write.graph.pajek(graph, file, ...) :
          At rinterface.c:761 : No such attribute, Invalid value
        Error during wrapup:
        >

I guess I'm having some trivial error here, could you help me a bit?

I Googled the message but haven't found anything.

I found the list archives, and found some hints to update to the most 
recent version of igraph. I've just updated to igraph_0.5.5-3 rj_0.5.5-4 
(based on the sessionInfo()), but still no change.

I've also tried some alternatives like using set.vertex.attribute and ' 
and ` characters to define the color values, but wasn't able to make it 
work.

http://lists.gnu.org/archive/html/igraph-help/2011-02/msg00021.html
http://lists.gnu.org/archive/html/igraph-help/2011-02/msg00022.html
http://lists.gnu.org/archive/html/igraph-help/2011-02/msg00078.html

Based on the documentation I found in ?read.graph, there are two tables 
stating that the color values should work (if I got it right).

The issue is not a big concern, the format is very simple so I could 
write a small R function that does the job, but I didn't get what do I 
wrong here.

I also found that the result may contain the " characters, but ain't 
sure how to define the color values without them:

http://lists.gnu.org/archive/html/igraph-help/2011-02/msg00043.html

I'm using R version 2.12.1 (2010-12-16), Platform: x86_64-pc-mingw32/x64 
(64-bit).

I also wanted to thank you for your efforts creating this cool tool for us!

Thank you in advance for your kind help.

All the best,
Richard
--
Richard O. Legendi
PhD Student
Eötvös Loránd University, Faculty of Informatics
Department of Programming Languages and Compilers
http://people.inf.elte.hu/legendi/