Re: Displaying large graphs

[Stefan Balev <stefan.balev AT gmail.com>]

Hi,

My best guess is that you are reaching some limits: of your hardware, of Java2D or of the layout algorithm. When you see a single dot the layout runs, but it just takes too long. There are several things you can try without warranty of success.

 - Activate Java2D hardware acceleration.

 - Simplify your stylesheets as much as possible, the best will be no styling at all, but at least avoid dynamic colors. Btw, why you assign "ui.class" attribute twice?

 - Be patient. Run your application in the evening, if you are lucky you will see something the next morning.

If you are impatient and want to see some action, try to display the graph before the loop. In the loop, add something like

int edges = 0;

for (...) {

    ....

    if (strength > 0) {

        ....

        edges++;

    }

    if (edges % a == 0) Thread.sleep(b);

}

Adjust a and b for best results.

However, sorry to repeat myself, but I keep thinking that displaying directly graphs of this size is pointless, all you will see is probably a big messy ball.

Cheers,

--

Stefan

2016-04-12 17:19 GMT+02:00 Cherie Pun <cherie.cy.pun AT gmail.com>:

Hi,

I am trying to display a graph with 457555 edges but it shows up as a single dot on my computer. If I limit to 5000 edges, it shows a graph as attached below. Is there a reason why it's doing this? I am using a hashmap to store the edges and the following code to construct the graph. Thank you very much for your help.

private static void displayGraph(HashMap<UserPair, TrustRelation> map) {
    Graph graph = new SingleGraph("Trust");
    graph.setStrict(false);
    graph.setAutoCreate( true );
    graph.addAttribute("ui.stylesheet", STYLE_SHEET);
    for(Map.Entry<UserPair, TrustRelation> entry : map.entrySet()){
        UserPair up = entry.getKey();
        TrustRelation tr = entry.getValue();
        double strengthOfTrust = tr.computeConversationalTrust();
        if (strengthOfTrust > 0) {
            Edge edge = graph.addEdge(up.toString(), Integer.toString(up.getUserA()), Integer.toString(up.getUserB()));
            edge.addAttribute("weight", strengthOfTrust);
            edge.addAttribute("ui.class", "untrustworthy");
            edge.addAttribute("ui.class", "trustworthy");
            edge.setAttribute("ui.color", strengthOfTrust/4.0);
        }

    }

    graph.display();
}

Kind regards,

Cherie