ZDT1.h
Go to the documentation of this file.
1//===========================================================================
2/*!
3 *
4 *
5 * \brief Multi-objective optimization benchmark function ZDT1
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 * <https://shark-ml.github.io/Shark/>
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
42#ifndef SHARK_OBJECTIVEFUNCTIONS_BENCHMARK_ZDT1_H
43#define SHARK_OBJECTIVEFUNCTIONS_BENCHMARK_ZDT1_H
44
45#include <shark/ObjectiveFunctions/AbstractObjectiveFunction.h>
46#include <shark/ObjectiveFunctions/BoxConstraintHandler.h>
47
48namespace shark {namespace benchmarks{
49/*! \brief Multi-objective optimization benchmark function ZDT1
50*
51* The function is described in
52*
53* Eckart Zitzler, Kalyanmoy Deb, and Lothar Thiele. Comparison of
54* Multiobjective Evolutionary Algorithms: Empirical
55* Results. Evolutionary Computation 8(2):173-195, 2000
56* \ingroup benchmarks
57*/
58struct ZDT1 : public MultiObjectiveFunction
59{
60
61 ZDT1(std::size_t numVariables = 0) : m_handler(numVariables,0,1) {
62 announceConstraintHandler(&m_handler);
63 }
64
65 /// \brief From INameable: return the class name.
66 std::string name() const
67 { return "ZDT1"; }
68
69 std::size_t numberOfObjectives()const{
70 return 2;
71 }
72
73 std::size_t numberOfVariables()const{
74 return m_handler.dimensions();
75 }
76
77 bool hasScalableDimensionality()const{
78 return true;
79 }
80
81 /// \brief Adjusts the number of variables if the function is scalable.
82 /// \param [in] numberOfVariables The new dimension.
83 void setNumberOfVariables( std::size_t numberOfVariables ){
84 m_handler.setBounds(numberOfVariables,0,1);
85 }
86
87 ResultType eval( const SearchPointType & x ) const {
88 m_evaluationCounter++;
89
90 ResultType value( 2 );
91
92 value[0] = x( 0 );
93
94 double g = 1.0 + 9.0 *(sum(x)-x(0))/(numberOfVariables() - 1.0);
95 double h = 1.0 - std::sqrt(x( 0 ) / g);
96
97 value[1] = g * h;
98
99 return value;
100 }
101
102private:
103 BoxConstraintHandler<SearchPointType> m_handler;
104};
105
106}}
107#endif