Repast Java: Creating a custom edge agent to schedule specific actions

问题

I have a model with a lot of edges (links) between different sorts of other agents (objects). I would like to model these edges as agents where I could add attributes and schedule actions. It is helpful to see a simple example of how to do this job?

update: I followed your instructions and get an error when running the model:

FATAL [Thread-2] 12:45:02,901 repast.simphony.ui.GUIScheduleRunner - RunTimeException when running the schedule
Current tick (1.0)
java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
    at repast.simphony.engine.schedule.DynamicTargetAction.execute(DynamicTargetAction.java:72)
    at repast.simphony.engine.controller.ScheduledMethodControllerAction$ScheduleMethodAllAction.execute(ScheduledMethodControllerAction.java:333)
    at repast.simphony.engine.schedule.DefaultAction.execute(DefaultAction.java:38)
    at repast.simphony.engine.schedule.ScheduleGroup.executeList(ScheduleGroup.java:205)
    at repast.simphony.engine.schedule.ScheduleGroup.execute(ScheduleGroup.java:231)
    at repast.simphony.engine.schedule.Schedule.execute(Schedule.java:352)
    at repast.simphony.ui.GUIScheduleRunner$ScheduleLoopRunnable.run(GUIScheduleRunner.java:52)
    at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.reflect.InvocationTargetException
    at jzombies.Zombie$$FastClassByCGLIB$$6141f31.invoke(<generated>)
    at net.sf.cglib.reflect.FastMethod.invoke(FastMethod.java:53)
    at repast.simphony.engine.schedule.DynamicTargetAction.execute(DynamicTargetAction.java:69)
    ... 7 more
Caused by: java.lang.NullPointerException
    at repast.simphony.query.PropertyGreaterThan.createPredicate(PropertyGreaterThan.java:72)
    at repast.simphony.query.AbstractPropertyQuery.query(AbstractPropertyQuery.java:83)
    at jzombies.Zombie.query_energy(Zombie.java:141)
    at jzombies.Zombie.step(Zombie.java:67)
    ... 10 more

I think it's affected by this method in Zombie: (but I have no idea where is wrong since the error message does not provide specific instruction)

    public void query_energy() {
//      Zombie this_zombie = new Zombie (space, grid, 9999);
        Context<Object> context = ContextUtils.getContext(this);
        Query<Object> query = new PropertyGreaterThan<Object>(context, "id", 2);
        for (Object o : query.query()) {
            Zombie h = (Zombie)o;
            System.out.println("zombie id: " + h.getID());
        }

    }

回答1:

Here's an example based on the JZombies_Demo model.

First create a CustomEdge class.

package jzombies;

import repast.simphony.space.graph.RepastEdge;

public class CustomEdge<T> extends RepastEdge<T> {

    private double customProperty;

    public double getCustomProperty() {
        return customProperty;
    }

    public void setCustomProperty(double customProperty) {
        this.customProperty = customProperty;
    }

    public CustomEdge(T source, T target, boolean directed, double weight) {
        super(source, target, directed, weight);
    }

    public CustomEdge(T source, T target, boolean directed) {
        super(source, target, directed);
    }

    public void customAction() {
        // define custom action here
    }
}

Then a CustomEdgeCreator class:

package jzombies;

import repast.simphony.space.graph.EdgeCreator;

public class CustomEdgeCreator<T> implements EdgeCreator<CustomEdge<T>, T> {

    public Class<CustomEdge> getEdgeType() {
        return CustomEdge.class;
    }

    public CustomEdge<T> createEdge(T source, T target, boolean isDirected, double weight) {
        return new CustomEdge<T>(source, target, isDirected, weight);
    }

}

Then when you define the NetworkBuilder in the JZombiesBuilder class you provide a CustomEdgeCreator instance:

NetworkBuilder<Object> netBuilder = new NetworkBuilder<Object>(
                "infection network", context, true).setEdgeCreator(new CustomEdgeCreator());
        netBuilder.buildNetwork();

At this point whenever you add an edge to the network you will be able to access the edge instance and schedule any custom action you define, for example like this in the Zombie class:

    Network<Object> net = (Network<Object>)context.getProjection("infection network");
    CustomEdge edge = (CustomEdge)net.addEdge(this, zombie);
    RunEnvironment.getInstance().getCurrentSchedule().schedule(
            ScheduleParameters.createOneTime(RunEnvironment.getInstance().getCurrentSchedule().getTickCount() + 20), edge, "customAction");

I hope this helps.

来源：https://stackoverflow.com/questions/57601451/repast-java-creating-a-custom-edge-agent-to-schedule-specific-actions

标签

repast-simphony