Layout subgraphs with different algorithms

hi,

1. have you tried to run your different Layouts just for a special group? For example use m_vis.addFocusGroup("firstGroup"); ... m_vis.getFocusGroup("firstGroup").addTuple(item)
to build your FocusGroups (also called secondary groups).
Later when creating your Layouts use new XYLayout("firstGroup"). The layout should just consider the items contained in the group "firstGroup"...
I'm doing this too and it works fine. A nice sideeffect: If you have this FocusGroups, its very easy to assign different renderers, colors, etc. to each FocusGroup.

2. Using this approach you better add multiple graphs to one visualization, using a different name each time you add a graph to the visualization. But again, you can't have edges between nodes of different graphs in a straightforward way.

greetz Björn

Thanks Bjoern,
  I should have mentioned that this was the first method I tried.  I'm intrigued that it works for you, because it doesn't work for me.  I think the problem ss that layouts like ForceDirectedLayout are expecting a composite tuple set with a node and edge subset, wheras addFocusGroup just creates a defaultTupleSet.

  Here's a small example where I tried to layout half the graph with ForceDirectedLayout.  Nothing happens at all when I pass in the focus group, but of course it lays out fine when I pass in the full graph.

import javax.swing.JFrame;
import prefuse.Display;
import prefuse.Visualization;
import prefuse.action.ActionList;
import prefuse.action.RepaintAction;
import prefuse.action.assignment.ColorAction;
import prefuse.action.layout.graph.ForceDirectedLayout;
import prefuse.activity.Activity;
import prefuse.controls.DragControl;
import prefuse.controls.PanControl;
import prefuse.data.Graph;
import prefuse.data.Table;
import prefuse.data.tuple.TupleSet;
import prefuse.render.DefaultRendererFactory;
import prefuse.util.ColorLib;
import prefuse.visual.VisualItem;

public class Example {

    public static void main(String[] argv) {
       
        Table nodes = new Table ();
        for (int i=0; i < 10; i++){
            nodes.addRow();
        }
       
        Table edges = new Table ();
        edges.addColumn (Graph.DEFAULT_SOURCE_KEY, int.class);
        edges.addColumn (Graph.DEFAULT_TARGET_KEY, int.class);
        for (int i=0; i <9; i++){
            int row =edges.addRow();
            edges.setInt (row,Graph.DEFAULT_SOURCE_KEY, i);
            edges.setInt (row, Graph.DEFAULT_TARGET_KEY, i+1);
        }
        Graph graph = new Graph(nodes,edges, false);
       
        Visualization vis = new Visualization();
        vis.addGraph("graph", graph);
        vis.addFocusGroup("subgraph");
        TupleSet subgraph = vis.getFocusGroup("subgraph");
     
        for (int i=0; i < 5; i++)
                subgraph.addTuple( nodes.getTuple(i));
       
        for (int i=0; i < 4; i++)
            subgraph.addTuple(edges.getTuple(i));
       
        vis.setRendererFactory(new DefaultRendererFactory());
        Display d = new Display(vis);
        d.setSize(720, 500);
        d.addControlListener(new DragControl());
        d.addControlListener(new PanControl());
       
        ColorAction fill = new ColorAction ("graph.nodes", VisualItem.FILLCOLOR, ColorLib.color(ColorLib.getColor(0,0,255,255)));
        ColorAction edgecolor = new ColorAction("graph.edges", VisualItem.STROKECOLOR, ColorLib.gray(200));
        ColorAction nStroke = new ColorAction("graph.nodes", VisualItem.STROKECOLOR,ColorLib.gray(100));
      
        ActionList color = new ActionList();
        color.add(nStroke);
        color.add(edgecolor);
        color.add(fill);
       
        ActionList layout = new ActionList(Activity.INFINITY);
        //Everything works fine...
        //layout.add (new ForceDirectedLayout("graph"));
       
        //Nothing happens
        layout.add (new ForceDirectedLayout("subgraph"));
        layout.add(new RepaintAction());
        vis.putAction("color", color);
        vis.putAction("layout", layout);

        JFrame frame = new JFrame("prefuse example");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(d);
        frame.pack();          
        frame.setVisible(true);
        vis.run("color");
        vis.run("layout");
    }   
}

I would love to see some sample code where you ran a layout on a focus group!  Thanks for the help,

Aaron