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CoinPresolveFixed.hpp
Go to the documentation of this file.
1 /* $Id: CoinPresolveFixed.hpp 2083 2019-01-06 19:38:09Z unxusr $ */
2 // Copyright (C) 2002, 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 #ifndef CoinPresolveFixed_H
7 #define CoinPresolveFixed_H
8 #define FIXED_VARIABLE 1
9
25 class remove_fixed_action : public CoinPresolveAction {
26 public:
30 struct action {
31 int col;
32 int start;
33 double sol;
34 };
36 int *colrows_;
38 double *colels_;
40 int nactions_;
42 action *actions_;
43
44 private:
46 remove_fixed_action(int nactions,
47 action *actions,
48 double *colels,
49 int *colrows,
50 const CoinPresolveAction *next);
51
52 public:
54 const char *name() const;
55
63 static const remove_fixed_action *presolve(CoinPresolveMatrix *prob,
64 int *fcols,
65 int nfcols,
66 const CoinPresolveAction *next);
67
68 void postsolve(CoinPostsolveMatrix *prob) const;
69
71 virtual ~remove_fixed_action();
72 };
73
81 const CoinPresolveAction *remove_fixed(CoinPresolveMatrix *prob,
82 const CoinPresolveAction *next);
83
93 class make_fixed_action : public CoinPresolveAction {
94
96 struct action {
97 double bound;
98 int col;
99 };
100
102 int nactions_;
104 const action *actions_;
105
110 const bool fix_to_lower_;
111
115 const remove_fixed_action *faction_;
116
118 make_fixed_action(int nactions, const action *actions, bool fix_to_lower,
119 const remove_fixed_action *faction,
120 const CoinPresolveAction *next)
121 : CoinPresolveAction(next)
122 , nactions_(nactions)
123 , actions_(actions)
124 , fix_to_lower_(fix_to_lower)
125 , faction_(faction)
126 {
127 }
128
129 public:
131 const char *name() const;
132
140 static const CoinPresolveAction *presolve(CoinPresolveMatrix *prob,
141 int *fcols,
142 int nfcols,
143 bool fix_to_lower,
144 const CoinPresolveAction *next);
145
150 void postsolve(CoinPostsolveMatrix *prob) const;
151
153 virtual ~make_fixed_action()
154 {
155 deleteAction(actions_, action *);
156 delete faction_;
157 }
158 };
159
167 const CoinPresolveAction *make_fixed(CoinPresolveMatrix *prob,
168 const CoinPresolveAction *next);
169
181 void transferCosts(CoinPresolveMatrix *prob);
182 #endif
183
184 /* vi: softtabstop=2 shiftwidth=2 expandtab tabstop=2
185 */
remove_fixed_action::postsolve
void postsolve(CoinPostsolveMatrix *prob) const
Apply the postsolve transformation for this particular presolve action.
make_fixed_action::action
Structure to preserve the bound overwritten when fixing a variable.
Definition: CoinPresolveFixed.hpp:96
remove_fixed_action::remove_fixed
const CoinPresolveAction * remove_fixed(CoinPresolveMatrix *prob, const CoinPresolveAction *next)
Scan the problem for fixed columns and remove them.
remove_fixed_action
Excise fixed variables from the model.
Definition: CoinPresolveFixed.hpp:25
remove_fixed_action::actions_
action * actions_
Vector specifying variable(s) affected by this object.
Definition: CoinPresolveFixed.hpp:42
make_fixed_action::action::col
int col
column index of variable
Definition: CoinPresolveFixed.hpp:98
make_fixed_action::action::bound
double bound
Value of bound overwritten to fix variable.
Definition: CoinPresolveFixed.hpp:97
CoinPresolveAction
Abstract base class of all presolve routines.
Definition: CoinPresolveMatrix.hpp:163
remove_fixed_action::action::start
int start
start of coefficients in colels_ and colrows_
Definition: CoinPresolveFixed.hpp:32
make_fixed_action::fix_to_lower_
const bool fix_to_lower_
True to fix at lower bound, false to fix at upper bound.
Definition: CoinPresolveFixed.hpp:110
deleteAction
#define deleteAction(array, type)
Definition: CoinPresolveMatrix.hpp:38
remove_fixed_action::~remove_fixed_action
virtual ~remove_fixed_action()
Destructor.
remove_fixed_action::name
const char * name() const
Returns string &quot;remove_fixed_action&quot;.
make_fixed_action::make_fixed
const CoinPresolveAction * make_fixed(CoinPresolveMatrix *prob, const CoinPresolveAction *next)
Scan variables and fix any with equal bounds.
remove_fixed_action::colrows_
int * colrows_
Array of row indices for coefficients of excised columns.
Definition: CoinPresolveFixed.hpp:36
make_fixed_action::postsolve
void postsolve(CoinPostsolveMatrix *prob) const
Postsolve (unfix variables)
make_fixed_action::name
const char * name() const
Returns string &quot;make_fixed_action&quot;.
remove_fixed_action::action::col
int col
column index of variable
Definition: CoinPresolveFixed.hpp:31
CoinPresolveAction::next
const CoinPresolveAction * next
The next presolve transformation.
Definition: CoinPresolveMatrix.hpp:180
make_fixed_action::make_fixed_action
make_fixed_action(int nactions, const action *actions, bool fix_to_lower, const remove_fixed_action *faction, const CoinPresolveAction *next)
Constructor.
Definition: CoinPresolveFixed.hpp:118
CoinPostsolveMatrix
Augments CoinPrePostsolveMatrix with information about the problem that is only needed during postsol...
Definition: CoinPresolveMatrix.hpp:1552
make_fixed_action::transferCosts
void transferCosts(CoinPresolveMatrix *prob)
Transfer costs from singleton variables.
remove_fixed_action::colels_
double * colels_
Array of coefficients of excised columns.
Definition: CoinPresolveFixed.hpp:38
CoinPresolveMatrix
Augments CoinPrePostsolveMatrix with information about the problem that is only needed during presolv...
Definition: CoinPresolveMatrix.hpp:905
remove_fixed_action::action::sol
double sol
value of variable
Definition: CoinPresolveFixed.hpp:33
make_fixed_action::~make_fixed_action
virtual ~make_fixed_action()
Destructor.
Definition: CoinPresolveFixed.hpp:153
remove_fixed_action::nactions_
int nactions_
Number of entries in actions_.
Definition: CoinPresolveFixed.hpp:40
make_fixed_action
Fix a variable at a specified bound.
Definition: CoinPresolveFixed.hpp:93
make_fixed_action::actions_
const action * actions_
Vector of preserved bounds, one for each variable fixed in this object.
Definition: CoinPresolveFixed.hpp:104
remove_fixed_action::remove_fixed_action
remove_fixed_action(int nactions, action *actions, double *colels, int *colrows, const CoinPresolveAction *next)
Constructor.
make_fixed_action::nactions_
int nactions_
Number of preserved bounds.
Definition: CoinPresolveFixed.hpp:102
make_fixed_action::faction_
const remove_fixed_action * faction_
The postsolve object with the information required to repopulate the fixed columns.
Definition: CoinPresolveFixed.hpp:115
remove_fixed_action::presolve
static const remove_fixed_action * presolve(CoinPresolveMatrix *prob, int *fcols, int nfcols, const CoinPresolveAction *next)
Excise the specified columns.
remove_fixed_action::action
Structure to hold information necessary to reintroduce a column into the problem representation.
Definition: CoinPresolveFixed.hpp:30
make_fixed_action::presolve
static const CoinPresolveAction * presolve(CoinPresolveMatrix *prob, int *fcols, int nfcols, bool fix_to_lower, const CoinPresolveAction *next)
Perform actions to fix variables and return postsolve object.