/* Copyright 2009-2015 David Hadka
*
* This file is part of the MOEA Framework.
*
* The MOEA Framework 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.
*
* The MOEA Framework 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 the MOEA Framework. If not, see <http://www.gnu.org/licenses/>.
*/
package org.moeaframework.problem.ZDT;
import org.moeaframework.core.Solution;
import org.moeaframework.core.variable.EncodingUtils;
/**
* The ZDT4 test problem.
*/
public class ZDT4 extends ZDT {
/**
* Constructs a ZDT4 test problem with 10 decision variables.
*/
public ZDT4() {
super(10);
}
/**
* Constructs a ZDT4 test problem with the specified number of decision
* variables.
*
* @param numberOfVariables the number of decision variables
*/
public ZDT4(int numberOfVariables) {
super(numberOfVariables);
}
@Override
public void evaluate(Solution solution) {
double[] x = EncodingUtils.getReal(solution);
double g = 0.0;
for (int i = 1; i < numberOfVariables; i++) {
g += Math.pow(x[i], 2.0) - 10.0 * Math.cos(4.0 * Math.PI * x[i]);
}
g += 1.0 + 10.0 * (numberOfVariables - 1);
double h = 1.0 - Math.sqrt(x[0] / g);
solution.setObjective(0, x[0]);
solution.setObjective(1, g * h);
}
}