// LexicoGraphicalComparator.java
//
// Author:
// Antonio J. Nebro <antonio@lcc.uma.es>
// Juan J. Durillo <durillo@lcc.uma.es>
//
// Copyright (c) 2011 Antonio J. Nebro, Juan J. Durillo
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package jmetal.qualityIndicator.util;
import java.util.Comparator;
/**
* This class implements the <code>Comparator</code> interface. It is used
* to compare points given as <code>double</code>.
* The order used is the lexicograhphical.
*/
public class LexicoGraphicalComparator implements Comparator{
/**
* The compare method compare 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;
//To determine the first i, that pointOne[i] != pointTwo[i];
int index = 0;
while ((index < pointOne.length) && (index < pointTwo.length) &&
pointOne[index] == pointTwo[index]) {
index++;
}
if ((index >= pointOne.length) || (index >= pointTwo.length )) {
return 0;
} else if (pointOne[index] < pointTwo[index]) {
return -1;
} else if (pointOne[index] > pointTwo[index]) {
return 1;
}
return 0;
} // compare
} // LexicoGraphicalComparator