/* Copyright 2009-2016 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.BBOB2016;
import org.moeaframework.core.Solution;
import org.moeaframework.core.variable.EncodingUtils;
/*
* The following source code is derived from the Coco Framework available at
* <https://github.com/numbbo/coco> under the 3-clause BSD license. The
* original code is copyright 2013 by the NumBBO/CoCO team. See the AUTHORS
* file located in the Coco Framework repository for more details.
*/
/**
* The Different Powers function. It is not intended for this function to be
* used directly since the BBOB test suite applies additional transformations
* to the test functions.
* <p>
* Properties:
* <ul>
* <li>High conditioning
* <li>Unimodal
* <li>Rotated
* <li>Small solution volume
* </ul>
*/
public class DifferentPowers extends BBOBFunction {
/**
* Constructs a new instance of the Different Powers function.
*
* @param numberOfVariables the number of decision variables
*/
public DifferentPowers(int numberOfVariables) {
super(numberOfVariables);
}
@Override
public void evaluate(Solution solution) {
double[] x = EncodingUtils.getReal(solution);
double sum = 0.0;
for (int i = 0; i < x.length; i++) {
double exponent = 2.0 + (4.0 * i / (x.length - 1.0));
sum += Math.pow(Math.abs(x[i]), exponent);
}
solution.setObjective(0, Math.sqrt(sum));
}
}