Hi given a graph G I want to compute a corresponding reachability graph; that is, for a given distance r, if the distance between two vertices is less than r they are joined by an edge. The shortest_distance function with the Johnson algorithm works fine but returns the distances between all pairs of vertices's and not just those with a distance less than r. Iterating through all distances and finding those with distance less than r is one solution but this is incredibly slow due to the size of my graph. Have you any suggestions? I’m considering using the breath first search functionality but I don’t think there is an option to terminate the search on parts the search tree with distance greater than r. thanks in advance -- 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.