// Viennet2.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.problems;
import jmetal.core.Problem;
import jmetal.core.Solution;
import jmetal.encodings.solutionType.BinaryRealSolutionType;
import jmetal.encodings.solutionType.RealSolutionType;
import jmetal.util.JMException;
/**
* Class representing problem Viennet2
*/
public class Viennet2 extends Problem{
/**
* Constructor.
* Creates a default instance of the Viennet2 problem
* @param solutionType The solution type must "Real" or "BinaryReal".
*/
public Viennet2(String solutionType) {
numberOfVariables_ = 2 ;
numberOfObjectives_ = 3 ;
numberOfConstraints_ = 0;
problemName_ = "Viennet4";
upperLimit_ = new double[numberOfVariables_];
lowerLimit_ = new double[numberOfVariables_];
for (int var = 0; var < numberOfVariables_; var++){
lowerLimit_[var] = -4.0;
upperLimit_[var] = 4.0;
} // for
if (solutionType.compareTo("BinaryReal") == 0)
solutionType_ = new BinaryRealSolutionType(this) ;
else if (solutionType.compareTo("Real") == 0)
solutionType_ = new RealSolutionType(this) ;
else {
System.out.println("Error: solution type " + solutionType + " invalid") ;
System.exit(-1) ;
}
} //Viennet2
/**
* Evaluates a solution
* @param solution The solution to evaluate
* @throws JMException
*/
public void evaluate(Solution solution) throws JMException {
double [] x = new double[numberOfVariables_];
double [] f = new double[numberOfObjectives_];
for (int i = 0; i < numberOfVariables_; i++)
x[i] = solution.getDecisionVariables()[i].getValue();
// First function
f[0] = (x[0]-2)*(x[0]-2)/2.0 + (x[1]+1)*(x[1]+1)/13.0 + 3.0 ;
// Second function
f[1] = (x[0]+x[1]-3.0)*(x[0]+x[1]-3.0)/36.0 +
(-x[0]+x[1]+2.0)*(-x[0]+x[1]+2.0)/8.0 - 17.0;
// Third function
f[2] = (x[0]+2*x[1]-1)*(x[0]+2*x[1]-1)/175.0 +
(2*x[1]-x[0])*(2*x[1]-x[0])/17.0 - 13.0 ;
for (int i = 0; i < numberOfObjectives_; i++)
solution.setObjective(i,f[i]);
} // evaluate
} // Viennet2