[igraph] Converting between the iGraph (edge-list) and Metis file format

[Alan Labouseur]

I would like to use Metis (http://glaros.dtc.umn.edu/gkhome/views/metis) to 
partition iGraph graphs. Is there an existing tool to export an iGraph graph in 
the Metis graph file format? I didn't see anything in the help for this, and a 
quick look online also yielded nothing. It's a fairly simple conversion but I 
want to ask the community before I go and write it myself.

Thanks!

-Alan

PS: Here's the Metis format:

%  This is a sample graph from page 11 of the METIS manual.
%  The first non-comment line lists the number of vertices (7) and edges (11).
%  The next non-comment line notes that vertex 1 is connected to vertices 5, 3 
and 2.
%  The next non-comment line notes that vertex 2 is connected to vertices 1, 3 
and 4.
%  ... and so on.
 7 11
% The following lines: adjacencies for vertex
 5 3 2
 1 3 4
 5 4 2 1
 2 3 6 7
 1 3 6
 5 4 7
 6 4