Re: IdAlreadyInUseException While Using BarabasiAlbertGenerator

["Jacob M. H. Smith" <jacob.m.h.smith AT gmail.com>]

Thank you for the reply, Stefan.

After having broken down my code to a minimal working example, I suspect that 
it has something to do with attributes and the layout or rendering algorithm. 
Here is code that produces the problem on my end.

/* ================================================== */
public static void main(String[] args) {
    Graph graph = new SingleGraph("graph");
    graph.display(true);

    graph.addAttribute("ui.quality");
    graph.addAttribute("ui.antialias");

    Generator generator = new BarabasiAlbertGenerator();
    generator.addSink(graph);
    generator.begin();
    for (int i = 0; i < 100; i++) {
        generator.nextEvents();
    }
    generator.end();

    graph.clear();

    graph.addAttribute("ui.quality");
    graph.addAttribute("ui.antialias");

    generator = new BarabasiAlbertGenerator();
    generator.addSink(graph);
    generator.begin();
    for (int i = 0; i < 100; i++) {
        generator.nextEvents();
    }
    generator.end();
}
/* ================================================== */

And here is the stacktrace it produces.

Exception in thread "Thread-1" org.miv.pherd.IdAlreadyInUseException: a 
particle with the same identifier already exists (0)
    at org.miv.pherd.ParticleBox.addParticle(ParticleBox.java:103)
    at 
org.graphstream.ui.layout.springbox.BarnesHutLayout.addNode(BarnesHutLayout.java:519)
    at 
org.graphstream.ui.layout.springbox.BarnesHutLayout.nodeAdded(BarnesHutLayout.java:680)
    at org.graphstream.stream.SourceBase.sendNodeAdded(SourceBase.java:323)
    at 
org.graphstream.stream.thread.ThreadProxyPipe.processMessage(ThreadProxyPipe.java:481)
    at 
org.graphstream.stream.thread.ThreadProxyPipe.pump(ThreadProxyPipe.java:264)
    at org.graphstream.ui.layout.LayoutRunner.run(LayoutRunner.java:179)

Best regards,
Jacob


On Sep 13, 2013, at 10:29 AM, Stefan Balev 
<stefan.balev AT gmail.com>
 wrote:

> Hi Jacob,
> 
> I could not reproduce this exception. I used the following code:
> 
>       public static void main(String[] args) {
>               Graph graph = new SingleGraph("test");
>               
>               Generator generator = new BarabasiAlbertGenerator();
>               generator.addSink(graph);
>               generator.begin();
>               for (int i = 0; i < 100; i++) {
>                   generator.nextEvents();
>               }
>               generator.end();
>               
>               graph.clear();
>               
>               generator = new BarabasiAlbertGenerator();
>               generator.addSink(graph);
>               generator.begin();
>               for (int i = 0; i < 100; i++) {
>                   generator.nextEvents();
>               }
>               generator.end();
>       }
> 
> which executes without exception. Are you sure that you really call 
> graph.clear()? If this is the case, could you provide more details, such as 
> a minimal code reproducing the exception and the stack trace?
> 
> Best,
> 
> --
> Stefan
> 
> 
> 2013/9/13 Jacob M. H. Smith 
> <jacob.m.h.smith AT gmail.com>
> Hello.
> 
> I'm using GraphStream 1.2 and I'm having the following problem.
> 
> I use the BarabasiAlbertGenerator to populate my graph like this:
> 
> /* ============================================== */
> Generator generator = new BarabasiAlbertGenerator();
> generator.addSink(graph);
> generator.begin();
> for (int i = 0; i < 100; i++) {
>     generator.nextEvents();
> }
> generator.end();
> /* ============================================== */
> 
> Later in my program I call the graph's clear() method and do the same thing 
> again. The second time I get an IdAlreadyInUseException.
> 
> What am I doing wrong? Am I using the generator or the graph in a way that 
> wasn't intended?
> 
> Best regards,
> Jacob
> 
>