source: trunk/Clp/src/AbcDualRowSteepest.hpp @ 2030

Last change on this file since 2030 was 1910, checked in by stefan, 7 years ago
  • add configure option --enable-aboca={1,2,3,4,yes,no}
  • compile Aboca source only if --enable-aboca set (instead of compiling empty source files)
  • fix svn properties
  • Property svn:keywords set to Id
File size: 4.5 KB
Line 
1/* $Id: AbcDualRowSteepest.hpp 1910 2013-01-27 02:00:13Z forrest $ */
2// Copyright (C) 2002, International Business Machines
3// Corporation and others, Copyright (C) 2012, FasterCoin.  All Rights Reserved.
4// This code is licensed under the terms of the Eclipse Public License (EPL).
5
6#ifndef AbcDualRowSteepest_H
7#define AbcDualRowSteepest_H
8
9#include "AbcDualRowPivot.hpp"
10class CoinIndexedVector;
11
12
13//#############################################################################
14
15/** Dual Row Pivot Steepest Edge Algorithm Class
16   
17    See Forrest-Goldfarb paper for algorithm
18   
19*/
20
21class AbcDualRowSteepest : public AbcDualRowPivot {
22 
23public:
24 
25  ///@name Algorithmic methods
26  //@{
27 
28  /// Returns pivot row, -1 if none
29  virtual int pivotRow();
30 
31  /** Updates weights and returns pivot alpha.
32      Also does FT update */
33  virtual double updateWeights(CoinIndexedVector & input,CoinIndexedVector & updatedColumn);
34  virtual double updateWeights1(CoinIndexedVector & input,CoinIndexedVector & updateColumn);
35  virtual void updateWeightsOnly(CoinIndexedVector & input);
36  /// Actually updates weights
37  virtual void updateWeights2(CoinIndexedVector & input,CoinIndexedVector & updateColumn);
38 
39  /** Updates primal solution (and maybe list of candidates)
40      Uses input vector which it deletes
41  */
42  virtual void updatePrimalSolution(CoinIndexedVector & input,
43                                    double theta);
44 
45  virtual void updatePrimalSolutionAndWeights(CoinIndexedVector & weightsVector,
46                                              CoinIndexedVector & updateColumn,
47                                              double theta);
48  /** Saves any weights round factorization as pivot rows may change
49      Save model
50      May also recompute infeasibility stuff
51      1) before factorization
52      2) after good factorization (if weights empty may initialize)
53      3) after something happened but no factorization
54      (e.g. check for infeasible)
55      4) as 2 but restore weights from previous snapshot
56      5) for strong branching - initialize (uninitialized) , infeasibilities
57  */
58  virtual void saveWeights(AbcSimplex * model, int mode);
59  /// Recompute infeasibilities
60  virtual void recomputeInfeasibilities();
61  /// Gets rid of all arrays
62  virtual void clearArrays();
63  /// Returns true if would not find any row
64  virtual bool looksOptimal() const;
65  //@}
66 
67  /** enums for persistence
68   */
69  enum Persistence {
70    normal = 0x00, // create (if necessary) and destroy
71    keep = 0x01 // create (if necessary) and leave
72  };
73 
74  ///@name Constructors and destructors
75  //@{
76  /** Default Constructor
77      0 is uninitialized, 1 full, 2 is partial uninitialized,
78      3 starts as 2 but may switch to 1.
79      By partial is meant that the weights are updated as normal
80      but only part of the infeasible basic variables are scanned.
81      This can be faster on very easy problems.
82  */
83  AbcDualRowSteepest(int mode = 3);
84 
85  /// Copy constructor
86  AbcDualRowSteepest(const AbcDualRowSteepest &);
87 
88  /// Assignment operator
89  AbcDualRowSteepest & operator=(const AbcDualRowSteepest& rhs);
90 
91  /// Fill most values
92  void fill(const AbcDualRowSteepest& rhs);
93 
94  /// Destructor
95  virtual ~AbcDualRowSteepest ();
96 
97  /// Clone
98  virtual AbcDualRowPivot * clone(bool copyData = true) const;
99 
100  //@}
101  /**@name gets and sets */
102  //@{
103  /// Mode
104  inline int mode() const {
105    return mode_;
106  }
107  /// Set/ get persistence
108  inline void setPersistence(Persistence life) {
109    persistence_ = life;
110  }
111  inline Persistence persistence() const {
112    return persistence_ ;
113  }
114  /// Infeasible vector
115  inline CoinIndexedVector * infeasible() const
116  { return infeasible_;}
117  /// Weights vector
118  inline CoinIndexedVector * weights() const
119  { return weights_;}
120  /// Model
121  inline AbcSimplex * model() const
122  { return model_;}
123  //@}
124 
125  //---------------------------------------------------------------------------
126 
127private:
128  ///@name Private member data
129  /// norm saved before going into update
130  double norm_;
131  /// Ratio of size of factorization to number of rows
132  double factorizationRatio_;
133  /** Status
134      0) Normal
135      -1) Needs initialization
136      1) Weights are stored by sequence number
137  */
138  int state_;
139  /** If 0 then we are using uninitialized weights, 1 then full,
140      if 2 then uninitialized partial, 3 switchable */
141  int mode_;
142  /// Life of weights
143  Persistence persistence_;
144  /// weight array
145  CoinIndexedVector * weights_;
146  /// square of infeasibility array (just for infeasible rows)
147  CoinIndexedVector * infeasible_;
148  /// save weight array (so we can use checkpoint)
149  CoinIndexedVector * savedWeights_;
150  //@}
151};
152
153// For Devex stuff
154#undef DEVEX_TRY_NORM
155#define DEVEX_TRY_NORM 1.0e-8
156#define DEVEX_ADD_ONE 1.0
157#endif
Note: See TracBrowser for help on using the repository browser.