Cigar.h
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1 /*!
2  *
3  *
4  * \brief Convex quadratic benchmark function with single dominant axis
5 
6  *
7  *
8  * \author -
9  * \date -
10  *
11  *
12  * \par Copyright 1995-2015 Shark Development Team
13  *
14  * <BR><HR>
15  * This file is part of Shark.
16  * <http://image.diku.dk/shark/>
17  *
18  * Shark is free software: you can redistribute it and/or modify
19  * it under the terms of the GNU Lesser General Public License as published
20  * by the Free Software Foundation, either version 3 of the License, or
21  * (at your option) any later version.
22  *
23  * Shark is distributed in the hope that it will be useful,
24  * but WITHOUT ANY WARRANTY; without even the implied warranty of
25  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
26  * GNU Lesser General Public License for more details.
27  *
28  * You should have received a copy of the GNU Lesser General Public License
29  * along with Shark. If not, see <http://www.gnu.org/licenses/>.
30  *
31  */
32 #ifndef SHARK_OBJECTIVEFUNCTIONS_BENCHMARKS_CIGAR_H
33 #define SHARK_OBJECTIVEFUNCTIONS_BENCHMARKS_CIGAR_H
34 
36 #include <shark/Rng/GlobalRng.h>
37 
38 namespace shark {
39 /**
40  * \brief Convex quadratic benchmark function with single dominant axis
41  */
42 struct Cigar : public SingleObjectiveFunction {
43 
44  Cigar(std::size_t numberOfVariables = 5, double alpha=1.E-3) : m_alpha(alpha) {
46  m_numberOfVariables = numberOfVariables;
47  }
48 
49  /// \brief From INameable: return the class name.
50  std::string name() const
51  { return "Cigar"; }
52 
53  std::size_t numberOfVariables()const{
54  return m_numberOfVariables;
55  }
56 
58  return true;
59  }
60 
62  m_numberOfVariables = numberOfVariables;
63  }
64 
66  RealVector x(numberOfVariables());
67 
68  for (std::size_t i = 0; i < x.size(); i++) {
69  x(i) = Rng::uni(0, 1);
70  }
71  return x;
72  }
73 
74  double eval(const SearchPointType &p) const {
76 
77  double sum = m_alpha * sqr(p(0));
78  for (std::size_t i = 1; i < p.size(); i++)
79  sum += sqr(p(i));
80 
81  return sum;
82  }
83 
84  double alpha() const {
85  return m_alpha;
86  }
87 
88  void setAlpha(double alpha) {
89  m_alpha = alpha;
90  }
91 
92 private:
93  double m_alpha;
94  std::size_t m_numberOfVariables;
95 };
96 }
97 
98 #endif // SHARK_EA_CIGAR_H