//  CEC2009_UF7.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_UF7
 */
public class UF7 extends Problem {
    
 /** 
  * Constructor.
  * Creates a default instance of problem CEC2009_UF7 (30 decision variables)
  * @param solutionType The solution type must "Real" or "BinaryReal".
  */
  public UF7(String solutionType) throws ClassNotFoundException {
    this(solutionType, 30); // 30 variables by default
  } // CEC2009_UF7
  
 /**
  * Creates a new instance of problem CEC2009_UF7.
  * @param numberOfVariables Number of variables.
  * @param solutionType The solution type must "Real" or "BinaryReal".
  */
  public UF7(String solutionType, Integer numberOfVariables) {
    numberOfVariables_  = numberOfVariables;
    numberOfObjectives_ =  2;
    numberOfConstraints_=  0;
    problemName_        = "CEC2009_UF7";

    upperLimit_ = new double[numberOfVariables_];
    lowerLimit_ = new double[numberOfVariables_];

        lowerLimit_[0] = 0.0 ;
     upperLimit_[0] = 1.0 ;
     for (int var = 1; var < numberOfVariables_; var++){
       lowerLimit_[var] = -1.0;
       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_UF7
    
  /** 
   * 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, yj;
		sum1   = sum2   = 0.0;
		count1 = count2 = 0;
    
    for (int j = 2 ; j <= numberOfVariables_; j++) {
			yj = x[j-1] - Math.sin(6.0*Math.PI*x[0]+j*Math.PI/numberOfVariables_);
			if (j % 2 == 0) {
				sum2  += yj*yj;
				count2++;
			} else {
				sum1  += yj*yj;
				count1++;
			}
    }
    yj = Math.pow(x[0],0.2);
    
    solution.setObjective(0, yj + 2.0*sum1 / (double)count1);
    solution.setObjective(1, 1.0 - yj + 2.0*sum2 / (double)count2);
  } // evaluate
} // CEC2009_UF7