[igraph] creating a graph from special piece of data

[Dominik Santner (CRIE)]

Hello,

I just started working with igraph in R, so I'm a kind of newbie. Maybe 
my problem is easy to solve, but I don't know how.

I want to create a graph from a piece of data. I just found on the 
internet information on how to create graphs from edge lists or 
adjacency matrices and how to add the attribute information from a 
separated list. Unfortunately my data are different. A simplified 
fictitious example is shown here:

Actor        Project    Type        Country
Miller Inc.        A1    Company        Canada
Bremen University    B6    University    Germany
Tokyo University    A1    University    Japan
Schulze GmbH        B2    Company        Germany
Miller Inc.        B2    Company        Canada
School authority London    B6    Authority    England
Meier AG        A1    Company        Austria
Meier AG        P7    Company        Austria
Athens University    K6    University    Greece


I want to receive a graph with edges indicating that actors work 
together in the same project (e.g. Miller Inc. and Tokyo University 
working together in project A1). Some actors are listed repeatedly 
(Miller Inc.) and some projects are run by only one actor (P7 by Meier 
AG). Some actors don't have any project partners at all (Athens 
University). Attribute data (type, country) are already included in this 
data frame.

How can I get an igraph graph from this kind of data including edge 
information and attribute data?

Thanks a lot in advance!
Dominik