Scippy

SCIP

Solving Constraint Integer Programs

cons_varbound.h
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3/* This file is part of the program and library */
4/* SCIP --- Solving Constraint Integer Programs */
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24
25/**@file cons_varbound.h
26 * @ingroup CONSHDLRS
27 * @brief Constraint handler for variable bound constraints \f$lhs \leq x + c y \leq rhs\f$.
28 * @author Tobias Achterberg
29 * @author Timo Berthold
30 * @author Michael Winkler
31 * @author Gerald Gamrath
32 * @author Stefan Heinz
33 *
34 */
35
36/*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
37
38#ifndef __SCIP_CONS_VARBOUND_H__
39#define __SCIP_CONS_VARBOUND_H__
40
41
42#include "scip/def.h"
43#include "scip/type_cons.h"
44#include "scip/type_lp.h"
45#include "scip/type_retcode.h"
46#include "scip/type_scip.h"
47#include "scip/type_var.h"
48
49#ifdef __cplusplus
50extern "C" {
51#endif
52
53/** creates the handler for variable bound constraints and includes it in SCIP
54 *
55 * @ingroup ConshdlrIncludes
56 */
57SCIP_EXPORT
59 SCIP* scip /**< SCIP data structure */
60 );
61
62/**@addtogroup CONSHDLRS
63 *
64 * @{
65 *
66 * @name Variable Bound Constraints
67 *
68 * @{
69 *
70 * This constraint handler handles a special type of linear constraints, namely variable bound constraints.
71 * A variable bound constraint has the form
72 * \f[
73 * lhs \leq x + c y \leq rhs
74 * \f]
75 * with coefficient \f$c \in Q\f$, \f$lhs\in Q \cup \{-\infty\}\f$, \f$rhs\in Q \cup \{\infty\}\f$,
76 * and decision variables \f$x\f$ (non-binary) and \f$y\f$ (binary or integer).
77 */
78
79/** creates and captures a variable bound constraint: lhs <= x + c*y <= rhs
80 *
81 * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()
82 */
83SCIP_EXPORT
85 SCIP* scip, /**< SCIP data structure */
86 SCIP_CONS** cons, /**< pointer to hold the created constraint */
87 const char* name, /**< name of constraint */
88 SCIP_VAR* var, /**< variable x that has variable bound */
89 SCIP_VAR* vbdvar, /**< binary, integer or implicit integer bounding variable y */
90 SCIP_Real vbdcoef, /**< coefficient c of bounding variable y */
91 SCIP_Real lhs, /**< left hand side of variable bound inequality */
92 SCIP_Real rhs, /**< right hand side of variable bound inequality */
93 SCIP_Bool initial, /**< should the LP relaxation of constraint be in the initial LP?
94 * Usually set to TRUE. Set to FALSE for 'lazy constraints'. */
95 SCIP_Bool separate, /**< should the constraint be separated during LP processing?
96 * Usually set to TRUE. */
97 SCIP_Bool enforce, /**< should the constraint be enforced during node processing?
98 * TRUE for model constraints, FALSE for additional, redundant constraints. */
99 SCIP_Bool check, /**< should the constraint be checked for feasibility?
100 * TRUE for model constraints, FALSE for additional, redundant constraints. */
101 SCIP_Bool propagate, /**< should the constraint be propagated during node processing?
102 * Usually set to TRUE. */
103 SCIP_Bool local, /**< is constraint only valid locally?
104 * Usually set to FALSE. Has to be set to TRUE, e.g., for branching constraints. */
105 SCIP_Bool modifiable, /**< is constraint modifiable (subject to column generation)?
106 * Usually set to FALSE. In column generation applications, set to TRUE if pricing
107 * adds coefficients to this constraint. */
108 SCIP_Bool dynamic, /**< is constraint subject to aging?
109 * Usually set to FALSE. Set to TRUE for own cuts which
110 * are separated as constraints. */
111 SCIP_Bool removable, /**< should the relaxation be removed from the LP due to aging or cleanup?
112 * Usually set to FALSE. Set to TRUE for 'lazy constraints' and 'user cuts'. */
113 SCIP_Bool stickingatnode /**< should the constraint always be kept at the node where it was added, even
114 * if it may be moved to a more global node?
115 * Usually set to FALSE. Set to TRUE to for constraints that represent node data. */
116 );
117
118/** creates and captures a varbound constraint
119 * in its most basic version, i. e., all constraint flags are set to their basic value as explained for the
120 * method SCIPcreateConsVarbound(); all flags can be set via SCIPsetConsFLAGNAME-methods in scip.h
121 *
122 * @see SCIPcreateConsVarbound() for information about the basic constraint flag configuration
123 *
124 * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()
125 */
126SCIP_EXPORT
128 SCIP* scip, /**< SCIP data structure */
129 SCIP_CONS** cons, /**< pointer to hold the created constraint */
130 const char* name, /**< name of constraint */
131 SCIP_VAR* var, /**< variable x that has variable bound */
132 SCIP_VAR* vbdvar, /**< binary, integer or implicit integer bounding variable y */
133 SCIP_Real vbdcoef, /**< coefficient c of bounding variable y */
134 SCIP_Real lhs, /**< left hand side of variable bound inequality */
135 SCIP_Real rhs /**< right hand side of variable bound inequality */
136 );
137
138/** gets left hand side of variable bound constraint lhs <= x + c*y <= rhs */
139SCIP_EXPORT
141 SCIP* scip, /**< SCIP data structure */
142 SCIP_CONS* cons /**< constraint data */
143 );
144
145/** gets right hand side of variable bound constraint lhs <= x + c*y <= rhs */
146SCIP_EXPORT
148 SCIP* scip, /**< SCIP data structure */
149 SCIP_CONS* cons /**< constraint data */
150 );
151
152/** gets bounded variable x of variable bound constraint lhs <= x + c*y <= rhs */
153SCIP_EXPORT
155 SCIP* scip, /**< SCIP data structure */
156 SCIP_CONS* cons /**< constraint data */
157 );
158
159/** gets bounding variable y of variable bound constraint lhs <= x + c*y <= rhs */
160SCIP_EXPORT
162 SCIP* scip, /**< SCIP data structure */
163 SCIP_CONS* cons /**< constraint data */
164 );
165
166/** gets bound coefficient c of variable bound constraint lhs <= x + c*y <= rhs */
167SCIP_EXPORT
169 SCIP* scip, /**< SCIP data structure */
170 SCIP_CONS* cons /**< constraint data */
171 );
172
173/** gets the dual solution of the variable bound constraint in the current LP */
174SCIP_EXPORT
176 SCIP* scip, /**< SCIP data structure */
177 SCIP_CONS* cons /**< constraint data */
178 );
179
180/** gets the dual Farkas value of the variable bound constraint in the current infeasible LP */
181SCIP_EXPORT
183 SCIP* scip, /**< SCIP data structure */
184 SCIP_CONS* cons /**< constraint data */
185 );
186
187/** returns the linear relaxation of the given variable bound constraint; may return NULL if no LP row was yet created;
188 * the user must not modify the row!
189 */
190SCIP_EXPORT
192 SCIP* scip, /**< SCIP data structure */
193 SCIP_CONS* cons /**< constraint data */
194 );
195
196/** cleans up (multi-)aggregations and fixings from varbound constraints */
197SCIP_EXPORT
199 SCIP* scip, /**< SCIP data structure */
200 SCIP_Bool onlychecked, /**< should only checked constraints be cleaned up? */
201 SCIP_Bool* infeasible, /**< pointer to return whether the problem was detected to be infeasible */
202 int* naddconss, /**< pointer to count number of added (linear) constraints */
203 int* ndelconss, /**< pointer to count number of deleted (varbound) constraints */
204 int* nchgbds /**< pointer to count number of bound changes */
205 );
206
207/** @} */
208
209/** @} */
210
211#ifdef __cplusplus
212}
213#endif
214
215#endif
common defines and data types used in all packages of SCIP
#define SCIP_Bool
Definition: def.h:91
#define SCIP_Real
Definition: def.h:173
SCIP_Real SCIPgetVbdcoefVarbound(SCIP *scip, SCIP_CONS *cons)
SCIP_Real SCIPgetDualfarkasVarbound(SCIP *scip, SCIP_CONS *cons)
SCIP_RETCODE SCIPcreateConsBasicVarbound(SCIP *scip, SCIP_CONS **cons, const char *name, SCIP_VAR *var, SCIP_VAR *vbdvar, SCIP_Real vbdcoef, SCIP_Real lhs, SCIP_Real rhs)
SCIP_ROW * SCIPgetRowVarbound(SCIP *scip, SCIP_CONS *cons)
SCIP_VAR * SCIPgetVbdvarVarbound(SCIP *scip, SCIP_CONS *cons)
SCIP_RETCODE SCIPcleanupConssVarbound(SCIP *scip, SCIP_Bool onlychecked, SCIP_Bool *infeasible, int *naddconss, int *ndelconss, int *nchgbds)
SCIP_VAR * SCIPgetVarVarbound(SCIP *scip, SCIP_CONS *cons)
SCIP_Real SCIPgetLhsVarbound(SCIP *scip, SCIP_CONS *cons)
SCIP_Real SCIPgetRhsVarbound(SCIP *scip, SCIP_CONS *cons)
SCIP_Real SCIPgetDualsolVarbound(SCIP *scip, SCIP_CONS *cons)
SCIP_RETCODE SCIPcreateConsVarbound(SCIP *scip, SCIP_CONS **cons, const char *name, SCIP_VAR *var, SCIP_VAR *vbdvar, SCIP_Real vbdcoef, SCIP_Real lhs, SCIP_Real rhs, SCIP_Bool initial, SCIP_Bool separate, SCIP_Bool enforce, SCIP_Bool check, SCIP_Bool propagate, SCIP_Bool local, SCIP_Bool modifiable, SCIP_Bool dynamic, SCIP_Bool removable, SCIP_Bool stickingatnode)
SCIP_RETCODE SCIPincludeConshdlrVarbound(SCIP *scip)
type definitions for constraints and constraint handlers
type definitions for LP management
type definitions for return codes for SCIP methods
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
type definitions for SCIP's main datastructure
type definitions for problem variables