ZDT3.h
Go to the documentation of this file.
1 //===========================================================================
2 /*!
3  *
4  *
5  * \brief Multi-objective optimization benchmark function ZDT3
6  *
7  * The function is described in
8  *
9  * Eckart Zitzler, Kalyanmoy Deb, and Lothar Thiele. Comparison of
10  * Multiobjective Evolutionary Algorithms: Empirical
11  * Results. Evolutionary Computation 8(2):173-195, 2000
12  *
13  *
14  *
15  * \author -
16  * \date -
17  *
18  *
19  * \par Copyright 1995-2017 Shark Development Team
20  *
21  * <BR><HR>
22  * This file is part of Shark.
23  * <http://shark-ml.org/>
24  *
25  * Shark is free software: you can redistribute it and/or modify
26  * it under the terms of the GNU Lesser General Public License as published
27  * by the Free Software Foundation, either version 3 of the License, or
28  * (at your option) any later version.
29  *
30  * Shark is distributed in the hope that it will be useful,
31  * but WITHOUT ANY WARRANTY; without even the implied warranty of
32  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
33  * GNU Lesser General Public License for more details.
34  *
35  * You should have received a copy of the GNU Lesser General Public License
36  * along with Shark. If not, see <http://www.gnu.org/licenses/>.
37  *
38  */
39 //===========================================================================
40 
41 #ifndef SHARK_OBJECTIVEFUNCTIONS_BENCHMARK_ZDT3_H
42 #define SHARK_OBJECTIVEFUNCTIONS_BENCHMARK_ZDT3_H
43 
44 #include <shark/ObjectiveFunctions/AbstractObjectiveFunction.h>
45 #include <shark/ObjectiveFunctions/BoxConstraintHandler.h>
46 
47 namespace shark {
48 /*! \brief Multi-objective optimization benchmark function ZDT3
49 *
50 * The function is described in
51 *
52 * Eckart Zitzler, Kalyanmoy Deb, and Lothar Thiele. Comparison of
53 * Multiobjective Evolutionary Algorithms: Empirical
54 * Results. Evolutionary Computation 8(2):173-195, 2000
55 */
56 struct ZDT3 : public MultiObjectiveFunction
57 {
58  ZDT3(std::size_t numVariables = 0) : m_handler(numVariables,0,1){
59  announceConstraintHandler(&m_handler);
60  }
61 
62  /// \brief From INameable: return the class name.
63  std::string name() const
64  { return "ZDT3"; }
65 
66  std::size_t numberOfVariables()const{
67  return m_handler.dimensions();
68  }
69 
70  bool hasScalableDimensionality()const{
71  return true;
72  }
73 
74  /// \brief Adjusts the number of variables if the function is scalable.
75  /// \param [in] numberOfVariables The new dimension.
76  void setNumberOfVariables( std::size_t numberOfVariables ){
77  m_handler.setBounds(numberOfVariables,0,1);
78  }
79 
80  std::size_t numberOfObjectives()const{
81  return 2;
82  }
83 
84  ResultType eval( const SearchPointType & x ) const {
85  m_evaluationCounter++;
86 
87  ResultType value( 2 );
88 
89  value[0] = x( 0 );
90 
91  double g = 1.0 + 9.0 *(sum(x)-x(0))/(numberOfVariables() - 1.0);
92  double h = 1.0 - std::sqrt(x(0) / g) - (x(0) / g) * std::sin(10 * M_PI * x(0));
93 
94  value[1] = g * h;
95 
96  return value;
97  }
98 
99 private:
100  BoxConstraintHandler<SearchPointType> m_handler;
101 };
102 }
103 #endif