// DTLZ3.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.DTLZ;
import jmetal.core.Problem;
import jmetal.core.Solution;
import jmetal.core.Variable;
import jmetal.encodings.solutionType.BinaryRealSolutionType;
import jmetal.encodings.solutionType.RealSolutionType;
import jmetal.util.JMException;
/**
* Class representing problem DTLZ3
*/
public class DTLZ3 extends Problem{
/**
* Creates a default DTLZ3 problem (12 variables and 3 objectives)
* @param solutionType The solution type must "Real" or "BinaryReal".
*/
public DTLZ3(String solutionType) throws ClassNotFoundException {
this(solutionType, 12, 3);
} // DTLZ3
/**
* Creates a new DTLZ3 problem instance
* @param numberOfVariables Number of variables
* @param numberOfObjectives Number of objective functions
* @param solutionType The solution type must "Real" or "BinaryReal".
*/
public DTLZ3(String solutionType,
Integer numberOfVariables,
Integer numberOfObjectives) {
numberOfVariables_ = numberOfVariables;
numberOfObjectives_ = numberOfObjectives;
numberOfConstraints_ = 0;
problemName_ = "DTLZ3";
lowerLimit_ = new double[numberOfVariables_];
upperLimit_ = new double[numberOfVariables_];
for (int var = 0; var < numberOfVariables_; var++){
lowerLimit_[var] = 0.0;
upperLimit_[var] = 1.0;
}
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) ;
}
}
/**
* Evaluates a solution
* @param solution The solution to evaluate
* @throws JMException
*/
public void evaluate(Solution solution) throws JMException {
Variable[] gen = solution.getDecisionVariables();
double [] x = new double[numberOfVariables_];
double [] f = new double[numberOfObjectives_];
int k = numberOfVariables_ - numberOfObjectives_ + 1;
for (int i = 0; i < numberOfVariables_; i++)
x[i] = gen[i].getValue();
double g = 0.0;
for (int i = numberOfVariables_ - k; i < numberOfVariables_; i++)
g += (x[i] - 0.5)*(x[i] - 0.5) - Math.cos(20.0 * Math.PI * (x[i] - 0.5));
g = 100.0 * (k + g);
for (int i = 0; i < numberOfObjectives_; i++)
f[i] = 1.0 + g;
for (int i = 0; i < numberOfObjectives_; i++){
for (int j = 0; j < numberOfObjectives_ - (i + 1); j++)
f[i] *= java.lang.Math.cos(x[j]*0.5*java.lang.Math.PI);
if (i != 0){
int aux = numberOfObjectives_ - (i + 1);
f[i] *= java.lang.Math.sin(x[aux]*0.5*java.lang.Math.PI);
} // if
} //for
for (int i = 0; i < numberOfObjectives_; i++)
solution.setObjective(i,f[i]);
} //evaluate
}