directed-graph

I have two lists of vertices: V and S . I would like to generate all possible directed graphs from V and S so, that each vertex from V has only one out-edge and exactly one in-edge, and each vertex from S can have any number of in- and out- edges. Each graph in the result should contain exactly all vertices from V and from S . The result can contain both connected and disconnected graphs. First I thought it was a powerset-related problem, but powerset has many other sets that may contain just one element (and I do not need those). My current strategy is to: find all pairs between vertices from

I am reading Introduction to Algorithms. In 22.5 Strongly Connected Component, the algorithm STRONGLY-CONNECTED-COMPONENT(G) is defined as: Call DFS(G) to compute finishing times u.f for each vertex u Compute G transpose Call DFS(G transpose), but in the main loop of DFS, consider the vertices in order of decreasing u.f(as computed in line 1) Output the vertices of each tree in the depth-first forest formed in line 3 as a separate strongly connected component If I change the alogrithm to just using G, without calculating G transpose. Also consider the vertices in order of Increasing u.f

I'm looking for a way to draw directed graphs in PHP. (as in http://upload.wikimedia.org/wikipedia/commons/0/08/Directed_acyclic_graph.png ). I want it to create an image of the graph just like GD can output an image. I've googled a lot on this, but I only can find a lot of libraries for drawing graphs in general (with bars etc), not directed graphs. P.S. I've tried using dot (the linux program) via system(), but unfortunately I have no permission to do that on the server. Also, I have no rights to install PHP extensions and stuff like that on the server, so it should work with normal PHP

Using the dot directed graph language, is it possible to create subgraphs with a different rankdir? I tried the following, which didn't work. Both graphs were left to right, despite the presence of rankdir="TB" in the subgraph. digraph g { rankdir="LR"; LEFT->RIGHT; clusterrank="local"; subgraph cluster1 { rankdir="TB"; node[style=filled]; color=black; TOP->BOTTOM; } } Is there some other syntax to get a Top/Bottom and Left/Right graph in the same diagram, or is this not possible? Seems like this is a long standing feature request: http://www.graphviz.org/bugs/b1279.html Desperately wanting

when I am ploting a directed graph with NetworkD3 , The edges are not directed , how can I fix it ? an Example : library(networkD3) data(MisLinks) data(MisNodes) forceNetwork(Links = MisLinks, Nodes = MisNodes, Source = "source", Target = "target", Value = "value", NodeID = "name", Group = "group", opacity = 0.8) I want the result to be directed This is the definetion of directed Graph: "A directed graph is graph, i.e., a set of objects (called vertices or nodes) that are connected together, where all the edges are directed from one vertex to another. A directed graph is sometimes called a

I have a directed graph and my problem is to enumerate all the minimal (cycles that cannot be constructed as the union of other cycles) directed cycles of this graph. This is different from what the Tarjan algorithm outputs. For instance, for the directed graph at this wikipedia page , I would like to get c <-> d and d <-> h as two separated directed cycles. I don't if this problem is polynomial or not. I ran over a paper "Enumerating Minimal Dicuts and Strongly Connected Subgraphs" that seems to conclude that this problem is incremental polynomial (I don't know what it means), but I am unable