[igraph] weighted graph

[Simone Gabbriellini]

dear list,

I have an igraph object with multiple edges.
I would like to simplify it, using simplify(), but I don't like to  
loose all that information;
I have all my data in edgelist format, so I am wondering if it's  
possible, while I read it with read.graph(), to convert multiple  
edges into one weighted edge.

I'm thinking about something like:

1 2
1 2
1 3
1 5

into

1 2 weight=2
1 3
1 5

thank you,
Simone