IcoLearner.java

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package sim.app.socialsystem;

import sim.util.MutableDouble3D;
import sim.util.MutableInt3D;

/**
 *
 * @author epokh
 * This class only compute the output generated by the distal error
 */
public class IcoLearner {


    private boolean noLearning=false;
    private double output;
    private MutableDouble3D derivReflex;
    private MutableDouble3D reflex;
    private MutableDouble3D Wdistal;
    private MutableDouble3D Wtemp;
    //this define the learning rate
    private double mu=0.01;
    //private MutableDouble3D Wreflex;
    //initialize with initial weights
    public IcoLearner()
    {
        Wdistal=new MutableDouble3D(1.0, 1.0, 1.0);
        Wtemp=new MutableDouble3D();
        reflex=new MutableDouble3D();
        derivReflex=new MutableDouble3D();
        derivReflex.zero();
        reflex.zero();
        Wtemp.zero();
    }

    //input is the distal error
    public double calculate(MutableInt3D reflex_int,MutableInt3D distal_int)
    {
     /*! decrease the energy of the robot */
    MutableDouble3D reflex_double=new MutableDouble3D(reflex_int);
    MutableDouble3D distal_double=new MutableDouble3D(distal_int);
	// if there's no learning the agent is only reactive
	  if(noLearning)
	  {
		/*! compute the next output */									
   	 	output=Wdistal.dot(distal_double);
	  }
	  else
	  {								
          //compute output
    	  output =Wdistal.dot(distal_double);
          //compute derivative of reflex dr=r(t)-r(t-1)
          derivReflex=reflex_double.subtract(reflex_double, reflex);
          //update r(t-1)
		  reflex.setTo(reflex_int);
		  // Learn and update the distal synaptic weights
          Wtemp.zero();
          Wtemp=derivReflex.multiply(derivReflex, mu);
          Wtemp.multiplyDot(Wtemp, distal_double);
		  Wdistal.addIn(Wtemp);
	  }
      return output;
    }

    public double getWeight(int type) {
        switch(type)
        {
            case DecisionMaker.B_AGENT:
                return Wdistal.x;
            case DecisionMaker.B_FOOD:
                return Wdistal.y;
            case DecisionMaker.B_AGENTFOOD:
                return Wdistal.z;
            default:
                return 0;
        }
    }
}