source: trunk/Cbc/src/CbcBranchToFixLots.hpp @ 1899

Last change on this file since 1899 was 1899, checked in by stefan, 5 years ago

fixup svn properties

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1// $Id: CbcBranchToFixLots.hpp 1899 2013-04-09 18:12:08Z stefan $
2// Copyright (C) 2004, International Business Machines
3// Corporation and others.  All Rights Reserved.
4// This code is licensed under the terms of the Eclipse Public License (EPL).
5
6// Edwin 11/13/2009-- carved out of CbcBranchCut
7
8#ifndef CbcBranchToFixLots_H
9#define CbcBranchToFixLots_H
10
11#include "CbcBranchCut.hpp"
12#include "CbcBranchBase.hpp"
13#include "OsiRowCut.hpp"
14#include "CoinPackedMatrix.hpp"
15
16/** Define a branch class that branches so that one way variables are fixed
17    while the other way cuts off that solution.
18    a) On reduced cost
19    b) When enough ==1 or <=1 rows have been satisfied (not fixed - satisfied)
20*/
21
22
23class CbcBranchToFixLots : public CbcBranchCut {
24
25public:
26
27    // Default Constructor
28    CbcBranchToFixLots ();
29
30    /** Useful constructor - passed reduced cost tolerance and fraction we would like fixed.
31        Also depth level to do at.
32        Also passed number of 1 rows which when clean triggers fix
33        Always does if all 1 rows cleaned up and number>0 or if fraction columns reached
34        Also whether to create branch if can't reach fraction.
35    */
36    CbcBranchToFixLots (CbcModel * model, double djTolerance,
37                        double fractionFixed, int depth,
38                        int numberClean = 0,
39                        const char * mark = NULL,
40                        bool alwaysCreate = false);
41
42    // Copy constructor
43    CbcBranchToFixLots ( const CbcBranchToFixLots &);
44
45    /// Clone
46    virtual CbcObject * clone() const;
47
48    // Assignment operator
49    CbcBranchToFixLots & operator=( const CbcBranchToFixLots& rhs);
50
51    // Destructor
52    ~CbcBranchToFixLots ();
53
54    /** Does a lot of the work,
55        Returns 0 if no good, 1 if dj, 2 if clean, 3 if both
56        FIXME: should use enum or equivalent to make these numbers clearer.
57    */
58    int shallWe() const;
59
60    /// Infeasibility for an integer variable - large is 0.5, but also can be infinity when known infeasible.
61    virtual double infeasibility(const OsiBranchingInformation * info,
62                                 int &preferredWay) const;
63    /** \brief Return true if object can take part in normal heuristics
64    */
65    virtual bool canDoHeuristics() const {
66        return true;
67    }
68
69    /// Creates a branching object
70    virtual CbcBranchingObject * createCbcBranch(OsiSolverInterface * solver, const OsiBranchingInformation * info, int way) ;
71    /// Redoes data when sequence numbers change
72    virtual void redoSequenceEtc(CbcModel * model, int numberColumns, const int * originalColumns);
73
74
75protected:
76    /// data
77
78    /// Reduced cost tolerance i.e. dj has to be >= this before fixed
79    double djTolerance_;
80    /// We only need to make sure this fraction fixed
81    double fractionFixed_;
82    /// Never fix ones marked here
83    char * mark_;
84    /// Matrix by row
85    CoinPackedMatrix matrixByRow_;
86    /// Do if depth multiple of this
87    int depth_;
88    /// number of ==1 rows which need to be clean
89    int numberClean_;
90    /// If true then always create branch
91    bool alwaysCreate_;
92};
93#endif
94
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