Griewangk.java

/*
  Copyright 2006 by Ankur Desai, Sean Luke, and George Mason University
  Licensed under the Academic Free License version 3.0
  See the file "LICENSE" for more information
*/

package sim.app.pso;

/**
   @author Ankur Desai and Joey Harrison
*/
public class Griewangk implements Evaluatable 
    {
    private static final long serialVersionUID = 1;

    public double calcFitness(double x, double y) 
        {
        return (1000 - (1 + (x*x) / 4000 + (y*y) / 4000 - Math.cos(x) * Math.cos(y / Math.sqrt(2))));
        }
    }