| 1 | gezelter | 1741 | /* -*- mode: c++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ | 
| 2 |  |  |  | 
| 3 |  |  | /* | 
| 4 |  |  | Copyright (C) 2001, 2002, 2003 Sadruddin Rejeb | 
| 5 |  |  |  | 
| 6 |  |  | This file is part of QuantLib, a free-software/open-source library | 
| 7 |  |  | for financial quantitative analysts and developers - http://quantlib.org/ | 
| 8 |  |  |  | 
| 9 |  |  | QuantLib is free software: you can redistribute it and/or modify it | 
| 10 |  |  | under the terms of the QuantLib license.  You should have received a | 
| 11 |  |  | copy of the license along with this program; if not, please email | 
| 12 |  |  | <quantlib-dev@lists.sf.net>. The license is also available online at | 
| 13 |  |  | <http://quantlib.org/license.shtml>. | 
| 14 |  |  |  | 
| 15 |  |  | This program is distributed in the hope that it will be useful, but WITHOUT | 
| 16 |  |  | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS | 
| 17 |  |  | FOR A PARTICULAR PURPOSE.  See the license for more details. | 
| 18 |  |  | */ | 
| 19 |  |  |  | 
| 20 |  |  | /*! \file constraint.hpp | 
| 21 |  |  | \brief Abstract constraint class | 
| 22 |  |  | */ | 
| 23 |  |  |  | 
| 24 |  |  | #ifndef quantlib_optimization_constraint_h | 
| 25 |  |  | #define quantlib_optimization_constraint_h | 
| 26 |  |  | #include "config.h" | 
| 27 |  |  | #include "math/DynamicVector.hpp" | 
| 28 |  |  |  | 
| 29 |  |  | using namespace OpenMD; | 
| 30 |  |  | namespace QuantLib { | 
| 31 |  |  |  | 
| 32 |  |  | //! Base constraint class | 
| 33 |  |  | class Constraint { | 
| 34 |  |  | protected: | 
| 35 |  |  | //! Base class for constraint implementations | 
| 36 |  |  | class Impl { | 
| 37 |  |  | public: | 
| 38 |  |  | virtual ~Impl() {} | 
| 39 |  |  | //! Tests if params satisfy the constraint | 
| 40 |  |  | virtual bool test(const DynamicVector<RealType>& params) const = 0; | 
| 41 |  |  | }; | 
| 42 |  |  | Impl* impl_; | 
| 43 |  |  | public: | 
| 44 |  |  | bool empty() const { return !impl_; } | 
| 45 |  |  | bool test(const DynamicVector<RealType>& p) const { return impl_->test(p); } | 
| 46 |  |  | RealType update(DynamicVector<RealType>& p, | 
| 47 |  |  | const DynamicVector<RealType>& direction, | 
| 48 |  |  | RealType beta); | 
| 49 |  |  | Constraint(Impl* impl = NULL); | 
| 50 |  |  | }; | 
| 51 |  |  |  | 
| 52 |  |  | //! No constraint | 
| 53 |  |  | class NoConstraint : public Constraint { | 
| 54 |  |  | private: | 
| 55 |  |  | class Impl : public Constraint::Impl { | 
| 56 |  |  | public: | 
| 57 |  |  | bool test(const DynamicVector<RealType>&) const { | 
| 58 |  |  | return true; | 
| 59 |  |  | } | 
| 60 |  |  | }; | 
| 61 |  |  | public: | 
| 62 |  |  | NoConstraint() | 
| 63 |  |  | : Constraint(new NoConstraint::Impl()) {} | 
| 64 |  |  | }; | 
| 65 |  |  |  | 
| 66 |  |  | //! %Constraint imposing positivity to all arguments | 
| 67 |  |  | class PositiveConstraint : public Constraint { | 
| 68 |  |  | private: | 
| 69 |  |  | class Impl : public Constraint::Impl { | 
| 70 |  |  | public: | 
| 71 |  |  | bool test(const DynamicVector<RealType>& params) const { | 
| 72 |  |  | for (size_t i=0; i<params.size(); ++i) { | 
| 73 |  |  | if (params[i] <= 0.0) | 
| 74 |  |  | return false; | 
| 75 |  |  | } | 
| 76 |  |  | return true; | 
| 77 |  |  | } | 
| 78 |  |  | }; | 
| 79 |  |  | public: | 
| 80 |  |  | PositiveConstraint() | 
| 81 |  |  | : Constraint(new PositiveConstraint::Impl) {} | 
| 82 |  |  | }; | 
| 83 |  |  |  | 
| 84 |  |  | //! %Constraint imposing all arguments to be in [low,high] | 
| 85 |  |  | class BoundaryConstraint : public Constraint { | 
| 86 |  |  | private: | 
| 87 |  |  | class Impl : public Constraint::Impl { | 
| 88 |  |  | public: | 
| 89 |  |  | Impl(RealType low, RealType high) | 
| 90 |  |  | : low_(low), high_(high) {} | 
| 91 |  |  | bool test(const DynamicVector<RealType>& params) const { | 
| 92 |  |  | for (size_t i=0; i<params.size(); i++) { | 
| 93 |  |  | if ((params[i] < low_) || (params[i] > high_)) | 
| 94 |  |  | return false; | 
| 95 |  |  | } | 
| 96 |  |  | return true; | 
| 97 |  |  | } | 
| 98 |  |  | private: | 
| 99 |  |  | RealType low_, high_; | 
| 100 |  |  | }; | 
| 101 |  |  | public: | 
| 102 |  |  | BoundaryConstraint(RealType low, RealType high) | 
| 103 |  |  | : Constraint( new BoundaryConstraint::Impl(low, high)) {} | 
| 104 |  |  | }; | 
| 105 |  |  |  | 
| 106 |  |  | //! %Constraint enforcing both given sub-constraints | 
| 107 |  |  | class CompositeConstraint : public Constraint { | 
| 108 |  |  | private: | 
| 109 |  |  | class Impl : public Constraint::Impl { | 
| 110 |  |  | public: | 
| 111 |  |  | Impl(const Constraint& c1, | 
| 112 |  |  | const Constraint& c2) | 
| 113 |  |  | : c1_(c1), c2_(c2) {} | 
| 114 |  |  | bool test(const DynamicVector<RealType>& params) const { | 
| 115 |  |  | return c1_.test(params) && c2_.test(params); | 
| 116 |  |  | } | 
| 117 |  |  | private: | 
| 118 |  |  | Constraint c1_, c2_; | 
| 119 |  |  | }; | 
| 120 |  |  | public: | 
| 121 |  |  | CompositeConstraint(const Constraint& c1, const Constraint& c2) | 
| 122 |  |  | : Constraint( new CompositeConstraint::Impl(c1,c2)) {} | 
| 123 |  |  | }; | 
| 124 |  |  |  | 
| 125 |  |  | } | 
| 126 |  |  |  | 
| 127 |  |  | #endif |