valuecomparator.java

关于多目标优化的代码

/**
 * ValueComparator.java
 *
 * @author Juan j.durillo
 * @version 1.0
 *
*/
package jmetal.qualityIndicator.util;

import java.util.Comparator;

/**
 * This class implemnents the <code>Comparator</code> interface. It is used
 * to compare points given as <code>double</code>. The points are compared
 * taken account the value of a index
 */
public class ValueComparator implements Comparator {
  
  /**
   * Stores the value of the index to compare
   */
  private int index_;               
  
  /**
   *  Constructor. 
   *  Creates a new instance of ValueComparator 
   */
  public ValueComparator(int index) {
    index_ = index;
  }
  
  /** 
   * Compares the objects o1 and o2.
   * @param o1 An object that reference a double[]
   * @param o2 An object that reference a double[]
   * @return -1 if o1 < o1, 1 if o1 > o2 or 0 in other case.
   */
  public int compare(Object o1, Object o2) {
    //Cast to double [] o1 and o2.
    double [] pointOne = (double [])o1;
    double [] pointTwo = (double [])o2;
    
    if (pointOne[index_] < pointTwo[index_]) {
      return -1;
    } else if (pointOne[index_] > pointTwo[index_]) {
      return 1;
    } else {
      return 0;
    }
  } // compare
} // ValueComparator