1 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ 2 /* */ 3 /* This file is part of the class library */ 4 /* SoPlex --- the Sequential object-oriented simPlex. */ 5 /* */ 6 /* Copyright (c) 1996-2023 Zuse Institute Berlin (ZIB) */ 7 /* */ 8 /* Licensed under the Apache License, Version 2.0 (the "License"); */ 9 /* you may not use this file except in compliance with the License. */ 10 /* You may obtain a copy of the License at */ 11 /* */ 12 /* http://www.apache.org/licenses/LICENSE-2.0 */ 13 /* */ 14 /* Unless required by applicable law or agreed to in writing, software */ 15 /* distributed under the License is distributed on an "AS IS" BASIS, */ 16 /* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. */ 17 /* See the License for the specific language governing permissions and */ 18 /* limitations under the License. */ 19 /* */ 20 /* You should have received a copy of the Apache-2.0 license */ 21 /* along with SoPlex; see the file LICENSE. If not email to soplex@zib.de. */ 22 /* */ 23 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ 24 25 /**@file spxharrisrt.h 26 * @brief Harris pricing with shifting. 27 */ 28 #ifndef _SPXHARRISRT_H_ 29 #define _SPXHARRISRT_H_ 30 31 #include <assert.h> 32 33 #include "soplex/spxdefines.h" 34 #include "soplex/spxratiotester.h" 35 36 namespace soplex 37 { 38 39 /**@brief Harris pricing with shifting. 40 @ingroup Algo 41 42 Class SPxHarrisRT is a stable implementation of a SPxRatioTester class 43 along the lines of Harris' two phase algorithm. Additionally it uses 44 shifting of bounds in order to avoid cycling. 45 46 See SPxRatioTester for a class documentation. 47 */ 48 /**@todo HarrisRT leads to cycling in dcmulti.sub.lp */ 49 template <class R> 50 class SPxHarrisRT : public SPxRatioTester<R> 51 { 52 private: 53 54 //------------------------------------- 55 /**@name Private helpers */ 56 ///@{ 57 /// 58 R degenerateEps() const; 59 60 /// 61 int maxDelta( 62 R* /*max*/, ///< max abs value in \p upd 63 R* val, ///< initial and chosen value 64 int num, ///< number of indices in \p idx 65 const int* idx, ///< nonzero indices in \p upd 66 const R* upd, ///< update VectorBase<R> for \p vec 67 const R* vec, ///< current vector 68 const R* low, ///< lower bounds for \p vec 69 const R* up ///< upper bounds for \p vec 70 ) const; 71 72 /// 73 int minDelta( 74 R* /*max*/, ///< max abs value in \p upd 75 R* val, ///< initial and chosen value 76 int num, ///< of indices in \p idx 77 const int* idx, ///< nonzero indices in \p upd 78 const R* upd, ///< update VectorBase<R> for \p vec 79 const R* vec, ///< current vector 80 const R* low, ///< lower bounds for \p vec 81 const R* up ///< upper bounds for \p vec 82 ) const; 83 ///@} 84 85 public: 86 87 //------------------------------------- 88 /**@name Construction / destruction */ 89 ///@{ 90 /// default constructor 91 SPxHarrisRT() 92 : SPxRatioTester<R>("Harris") 93 {} 94 /// copy constructor 95 SPxHarrisRT(const SPxHarrisRT& old) 96 : SPxRatioTester<R>(old) 97 {} 98 /// assignment operator 99 SPxHarrisRT& operator=(const SPxHarrisRT& rhs) 100 { 101 if(this != &rhs) 102 { 103 SPxRatioTester<R>::operator=(rhs); 104 } 105 106 return *this; 107 } 108 /// destructor 109 virtual ~SPxHarrisRT() 110 {} 111 /// clone function for polymorphism 112 inline virtual SPxRatioTester<R>* clone() const 113 { 114 return new SPxHarrisRT(*this); 115 } 116 ///@} 117 118 //------------------------------------- 119 /**@name Leave / enter */ 120 ///@{ 121 /// 122 virtual int selectLeave(R& val, R, bool); 123 /// 124 virtual SPxId selectEnter(R& val, int, bool); 125 ///@} 126 127 }; 128 129 } // namespace soplex 130 // For the general template 131 #include "spxharrisrt.hpp" 132 133 134 #endif // _SPXHARRISRT_H_ 135