4. Miscellaneous ‐ Stand‐alone Graph Manipulation

Stand-alone Graph Manipulation with ChronoGraph

Users are able to use ChronoGraph in a stand-alone mode. Here is the example to create a temporal property graph and analyze its information diffusion over time.

• Example: temporal information diffusion

• Users can use either in-memory graph or persistent graph

Graph g = new MChronoGraph();
Graph g = new PChronoGraph("mongodb://localhost:27017", "test");

• Create a graph

Vertex jack = g.addVertex("Jack");
Vertex sarah = g.addVertex("Sarah");
Vertex david = g.addVertex("David");
Vertex mary = g.addVertex("Mary");
Vertex emma = g.addVertex("Emma");

Edge js = g.addEdge(jack, sarah, "contact");
Edge sj = g.addEdge(sarah, jack, "contact");

Edge jm = g.addEdge(jack, mary, "contact");
Edge mj = g.addEdge(mary, jack, "contact");

Edge sd = g.addEdge(sarah, david, "contact");
Edge ds = g.addEdge(david, sarah, "contact");

Edge sm = g.addEdge(sarah, mary, "contact");
Edge ms = g.addEdge(mary, sarah, "contact");

Edge dm = g.addEdge(david, mary, "contact");
Edge md = g.addEdge(mary, david, "contact");

Edge de = g.addEdge(david, emma, "contact");
Edge ed = g.addEdge(emma, david, "contact");

jm.addEvent(1);
mj.addEvent(1);

sd.addEvent(2);
ds.addEvent(2);

js.addEvent(3);
sj.addEvent(3);

sm.addEvent(4);
ms.addEvent(4);

dm.addEvent(5);
md.addEvent(5);

de.addEvent(6);
ed.addEvent(6);

sd.addEvent(7);
ds.addEvent(7);

• Temporal Reachability (Allen Temporal Relation: 'isAfter')

HashMap<Vertex, Long> gamma = new HashMap<Vertex, Long>();
gamma.put(jack, 0l);
HashSet<VertexEvent> traversers = new HashSet<VertexEvent>();
traversers.add(jack.getEvent(0));
while (true) {
	HashSet<VertexEvent> newTraversers = new HashSet<VertexEvent>();
	for (VertexEvent t : traversers) {
		for (VertexEvent ot : t.getVertexEvents(Direction.OUT, TemporalRelation.isAfter, "contact")) {
			if (ot == null)
				continue;
			Vertex o = (Vertex) ot.getElement();
			if (gamma.containsKey(o) && (gamma.get(o) > ot.getTime())) {
					gamma.put(o, ot.getTime());
				newTraversers.add(ot);
			} else if (!gamma.containsKey(o)) {
				gamma.put(o, ot.getTime());
				newTraversers.add(ot);
			}
		}
	}
	if (newTraversers.isEmpty())
		break;
	else
		traversers = newTraversers;
	}
	System.out.println("Reachable from Jack: " + gamma);
    }
}