/* 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.misc; import org.moeaframework.core.Solution; import org.moeaframework.core.variable.RealVariable; import org.moeaframework.problem.AbstractProblem; /** * The Viennet (4) problem. * <p> * Properties: * <ul> * <li>Connected and asymmetric Pareto set * <li>Curved Pareto front * <li>Constrained * </ul> * <p> * References: * <ol> * <li>Viennet, R., et al (1996). "Multicriteria Optimization Using a * Genetic Algorithm for Determining a Pareto Set." International * Journal of Systems Science, 27(2):255-260. * <li>Van Veldhuizen, D. A (1999). "Multiobjective Evolutionary Algorithms: * Classifications, Analyses, and New Innovations." Air Force Institute * of Technology, Ph.D. Thesis, Appendix B. * </ol> */ public class Viennet4 extends AbstractProblem { /** * Constructs the Viennet (4) problem. */ public Viennet4() { super(2, 3, 3); } @Override public void evaluate(Solution solution) { double x = ((RealVariable)solution.getVariable(0)).getValue(); double y = ((RealVariable)solution.getVariable(1)).getValue(); double f1 = Math.pow(x - 2.0, 2.0) / 2.0 + Math.pow(y + 1.0, 2.0) / 13.0 + 3.0; double f2 = Math.pow(x + y - 3.0, 2.0) / 175.0 + Math.pow(2.0*y - x, 2.0) / 17.0 - 13.0; double f3 = Math.pow(3.0*x - 2.0*y + 4.0, 2.0) / 8.0 + Math.pow(x - y + 1.0, 2.0) / 27.0 + 15.0; //subtract Double.MIN_VALUE so that the constraint is satisfied only if //its values is strictly greater than 0 double c1 = -4.0*x + 4.0 - y - Double.MIN_VALUE; double c2 = x + 1 - Double.MIN_VALUE; double c3 = y - x + 2.0 - Double.MIN_VALUE; solution.setObjective(0, f1); solution.setObjective(1, f2); solution.setObjective(2, f3); solution.setConstraint(0, c1 >= 0.0 ? 0.0 : c1); solution.setConstraint(1, c2 >= 0.0 ? 0.0 : c2); solution.setConstraint(2, c3 >= 0.0 ? 0.0 : c3); } @Override public Solution newSolution() { Solution solution = new Solution(2, 3, 3); solution.setVariable(0, new RealVariable(-4.0, 4.0)); solution.setVariable(1, new RealVariable(-4.0, 4.0)); return solution; } }