Hi, Consider the following GraphML file (attached). According to the GraphML file, it represents an undirected graph. Therefore, I would expect that as I set it to directed graph: gtGraph=gt.load_graph("yeast.graphml") gtGraph.set_directed(1) I would obtain two directed edges for every undirected edge. In particular, the in degree of every node should be equal to the out degree. However, this is not the case, for example: v=gtGraph.vertex(1834) v.in_degree() Out[3]: 5 v.out_degree() Out[4]: 2 I'm a bit puzzled. A) Is the source file corrupted? B) When I set the directedness flag to 1, am I guaranteed that every undirected edge would be converted to two directed edges? If not, how can I perform this operation (A = A + A', assuming the adjacency matrix is triangular) or validate it? yeast.graphml <http://main-discussion-list-for-the-graph-tool-project.982480.n3.nabble.com/file/n4026916/yeast.graphml> -- View this message in context: http://main-discussion-list-for-the-graph-tool-project.982480.n3.nabble.com/... Sent from the Main discussion list for the graph-tool project mailing list archive at Nabble.com.