// CEC2009_UF3.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.cec2009Competition;
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 CEC2009_UF3
*/
public class UF3 extends Problem {
/**
* Constructor.
* Creates a default instance of problem CEC2009_UF3 (30 decision variables)
* @param solutionType The solution type must "Real" or "BinaryReal".
*/
public UF3(String solutionType) throws ClassNotFoundException {
this(solutionType, 30); // 30 variables by default
} // CEC2009_UF3
/**
* Creates a new instance of problem CEC2009_UF3.
* @param numberOfVariables Number of variables.
* @param solutionType The solution type must "Real" or "BinaryReal".
*/
public UF3(String solutionType, Integer numberOfVariables) {
numberOfVariables_ = numberOfVariables;
numberOfObjectives_ = 2;
numberOfConstraints_= 0;
problemName_ = "CEC2009_UF3";
upperLimit_ = new double[numberOfVariables_];
lowerLimit_ = new double[numberOfVariables_];
// Establishes upper and lower limits for the variables
for (int var = 0; var < numberOfVariables_; var++)
{
lowerLimit_[var] = 0.0;
upperLimit_[var] = 1.0;
} // 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) ;
}
} // CEC2009_UF3
/**
* Evaluates a solution.
* @param solution The solution to evaluate.
* @throws JMException
*/
public void evaluate(Solution solution) throws JMException {
Variable[] decisionVariables = solution.getDecisionVariables();
double [] x = new double[numberOfVariables_] ;
for (int i = 0; i < numberOfVariables_; i++)
x[i] = decisionVariables[i].getValue() ;
int count1, count2;
double sum1, sum2, prod1, prod2, yj, pj;
sum1 = sum2 = 0.0;
count1 = count2 = 0;
prod1 = prod2 = 1.0;
for (int j = 2 ; j <= numberOfVariables_; j++) {
yj = x[j-1]-Math.pow(x[0],0.5*(1.0+3.0*(j-2.0)/(numberOfVariables_-2.0)));
pj = Math.cos(20.0*yj*Math.PI/Math.sqrt(j));
if (j % 2 == 0) {
sum2 += yj*yj;
prod2 *= pj;
count2++;
} else {
sum1 += yj*yj;
prod1 *= pj;
count1++;
}
}
solution.setObjective(0, x[0] + 2.0*(4.0*sum1 - 2.0*prod1 + 2.0) / (double)count1);
solution.setObjective(1, 1.0 - Math.sqrt(x[0]) + 2.0*(4.0*sum2 - 2.0*prod2 + 2.0) / (double)count2);
} // evaluate
} // CEC2009_UF3