aggregativecomparator.java

关于多目标优化的代码

/**
 * AggregativeComparator.java
 *
 * @author Juan J. Durillo
 * @version 1.0
 */
package jmetal.base.operator.comparator;

import jmetal.base.Solution;
import java.util.Comparator;

/**
 * This class implements a <code>Comparator</code> (a method for comparing
 * <code>Solution</code> objects) based on the aggregative sum of the objective
 * values.
 */
public class AggregativeComparator implements Comparator{            
   
 /**
  * Compares two solutions.
  * @param o1 Object representing the first <code>Solution</code>.
  * @param o2 Object representing the second <code>Solution</code>.
  * @return -1, or 0, or 1 if o1 is less than, equal, or greater than o2,
  * respectively.
  */
  public int compare(Object o1, Object o2) {
    if (o1==null) {
      return 1;
    } else if (o2 == null) {
      return -1;
    }
    
    double value1, value2;
    Solution solution1 = (Solution)o1;
    Solution solution2 = (Solution)o2;    
    
    value1 = solution1.getAggregativeValue();
    value2 = solution2.getAggregativeValue();        
    if (value1 < value2)
      return -1;
    else if (value2 < value1)
      return 1;
    else 
      return 0;
  } // compare
} // AgregativeComparator