// OKA1.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.core.Variable;
import jmetal.encodings.solutionType.BinaryRealSolutionType;
import jmetal.encodings.solutionType.RealSolutionType;
import jmetal.util.JMException;
/**
* Class representing problem OKA1
*/
public class OKA1 extends Problem {
/**
* Constructor.
* Creates a new instance of the OKA2 problem.
* @param solutionType The solution type must "Real" or "BinaryReal".
*/
public OKA1(String solutionType) {
numberOfVariables_ = 2 ;
numberOfObjectives_ = 2 ;
numberOfConstraints_ = 0 ;
problemName_ = "OKA1" ;
upperLimit_ = new double[numberOfVariables_] ;
lowerLimit_ = new double[numberOfVariables_] ;
lowerLimit_[0] = 6 * Math.sin(Math.PI/12.0) ;
upperLimit_[0] = 6 * Math.sin(Math.PI/12.0) + 2 * Math.PI * Math.cos(Math.PI/12.0) ;
lowerLimit_[1] = -2 * Math.PI * Math.sin(Math.PI/12.0) ;
upperLimit_[1] = 6 * Math.cos(Math.PI/12.0) ;
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) ;
}
} // OKA1
/**
* Evaluates a solution
* @param solution The solution to evaluate
* @throws JMException
*/
public void evaluate(Solution solution) throws JMException {
Variable[] decisionVariables = solution.getDecisionVariables();
double [] fx = new double[numberOfObjectives_] ; // 2 functions
double [] x = new double[numberOfVariables_] ; // 2 variables
for (int i = 0; i < numberOfVariables_; i++)
x[i] = decisionVariables[i].getValue() ;
double x0 = Math.cos(Math.PI/12.0)*x[0] - Math.sin(Math.PI/12.0)*x[1] ;
double x1 = Math.sin(Math.PI/12.0)*x[0] + Math.cos(Math.PI/12.0)*x[1] ;
fx[0] = x0 ;
fx[1] = Math.sqrt(2 * Math.PI) - Math.sqrt(Math.abs(x0)) +
2 * Math.pow(Math.abs(x1 - 3 * Math.cos(x0) - 3), 1.0/3.0) ;
solution.setObjective(0, fx[0]);
solution.setObjective(1, fx[1]);
} // evaluate
} // OKA1