// Viennet4.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 Viennet4
*/
public class Viennet4 extends Problem{
/**
* Constructor.
* Creates a default instance of the Viennet4 problem.
* @param solutionType The solution type must "Real" or "BinaryReal".
*/
public Viennet4(String solutionType) {
numberOfVariables_ = 2 ;
numberOfObjectives_ = 3 ;
numberOfConstraints_ = 3 ;
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) ;
}
} //Viennet4
/**
* 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();
}
f[0] = (x[0]-2.0)*(x[0]-2.0)/2.0 +
(x[1]+1.0)*(x[1]+1.0)/13.0 + 3.0;
f[1] = (x[0]+ x[1]-3.0)*(x[0]+x[1]-3.0)/175.0 +
(2.0*x[1]-x[0])*(2.0*x[1]-x[0])/17.0 -13.0;
f[2] = (3.0*x[0]-2.0*x[1]+4.0)*(3.0*x[0]-2.0*x[1]+4.0)/8.0 +
(x[0]-x[1]+1.0)*(x[0]-x[1]+1.0)/27.0 + 15.0;
for (int i = 0; i < numberOfObjectives_; i++) {
solution.setObjective(i,f[i]);
}
} // evaluate
/**
* Evaluates the constraint overhead of a solution
* @param solution The solution
* @throws JMException
*/
public void evaluateConstraints(Solution solution) throws JMException {
double [] constraint = new double[numberOfConstraints_];
double x1 = solution.getDecisionVariables()[0].getValue();
double x2 = solution.getDecisionVariables()[1].getValue();
constraint[0] = -x2 - (4.0 * x1) + 4.0 ;
constraint[1] = x1 + 1.0 ;
constraint[2] = x2 - x1 + 2.0 ;
int number = 0;
double total = 0.0;
for (int i = 0; i < numberOfConstraints_; i++) {
if (constraint[i]<0.0){
number++;
total+=constraint[i];
}
}
solution.setOverallConstraintViolation(total);
solution.setNumberOfViolatedConstraint(number);
} // evaluateConstraints
} // Viennet4