# source:trunk/Clp/src/AbcDualRowDantzig.hpp@1879

Last change on this file since 1879 was 1878, checked in by forrest, 7 years ago

minor changes to implement Aboca

File size: 2.6 KB
Line
1/* \$Id: AbcDualRowDantzig.hpp 1665 2011-01-04 17:55:54Z lou \$ */
5
6#ifndef AbcDualRowDantzig_H
7#define AbcDualRowDantzig_H
8
9#include "AbcDualRowPivot.hpp"
10
11//#############################################################################
12
13/** Dual Row Pivot Dantzig Algorithm Class
14
15    This is simplest choice - choose largest infeasibility
16
17*/
18
19class AbcDualRowDantzig : public AbcDualRowPivot {
20
21public:
22
23  ///@name Algorithmic methods
24  //@{
25
26  /// Returns pivot row, -1 if none
27  virtual int pivotRow();
28
29  /** Updates weights and returns pivot alpha.
30      Also does FT update */
31  virtual double updateWeights(CoinIndexedVector & input,CoinIndexedVector & updatedColumn);
32  virtual double updateWeights1(CoinIndexedVector & input,CoinIndexedVector & updateColumn);
33  virtual void updateWeightsOnly(CoinIndexedVector & /*input*/) {};
35  virtual void updateWeights2(CoinIndexedVector & input,CoinIndexedVector & /*updateColumn*/) {input.clear();};
36  /** Updates primal solution (and maybe list of candidates)
37      Uses input vector which it deletes
38      Computes change in objective function
39  */
40  virtual void updatePrimalSolution(CoinIndexedVector & input,
41                                    double theta);
42  /** Saves any weights round factorization as pivot rows may change
43      Will be empty unless steepest edge (will save model)
44      May also recompute infeasibility stuff
45      1) before factorization
46      2) after good factorization (if weights empty may initialize)
47      3) after something happened but no factorization
48      (e.g. check for infeasible)
49      4) as 2 but restore weights from previous snapshot
50      5) for strong branching - initialize  , infeasibilities
51  */
52  virtual void saveWeights(AbcSimplex * model, int mode);
53  /// Recompute infeasibilities
54  virtual void recomputeInfeasibilities();
55  //@}
56
57
58  ///@name Constructors and destructors
59  //@{
60  /// Default Constructor
61  AbcDualRowDantzig();
62
63  /// Copy constructor
64  AbcDualRowDantzig(const AbcDualRowDantzig &);
65
66  /// Assignment operator
67  AbcDualRowDantzig & operator=(const AbcDualRowDantzig& rhs);
68
69  /// Destructor
70  virtual ~AbcDualRowDantzig ();
71
72  /// Clone
73  virtual AbcDualRowPivot * clone(bool copyData = true) const;
74
75  //@}
76
77  //---------------------------------------------------------------------------
78
79private:
80  ///@name Private member data
81  /// infeasibility array (just for infeasible rows)
82  CoinIndexedVector * infeasible_;
83  //@}
84};
85
86#endif
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