Scippy

SCIP

Solving Constraint Integer Programs

cons_logicor.h
Go to the documentation of this file.
1/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
2/* */
3/* This file is part of the program and library */
4/* SCIP --- Solving Constraint Integer Programs */
5/* */
6/* Copyright (c) 2002-2024 Zuse Institute Berlin (ZIB) */
7/* */
8/* Licensed under the Apache License, Version 2.0 (the "License"); */
9/* you may not use this file except in compliance with the License. */
10/* You may obtain a copy of the License at */
11/* */
12/* http://www.apache.org/licenses/LICENSE-2.0 */
13/* */
14/* Unless required by applicable law or agreed to in writing, software */
15/* distributed under the License is distributed on an "AS IS" BASIS, */
16/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. */
17/* See the License for the specific language governing permissions and */
18/* limitations under the License. */
19/* */
20/* You should have received a copy of the Apache-2.0 license */
21/* along with SCIP; see the file LICENSE. If not visit scipopt.org. */
22/* */
23/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
24
25/**@file cons_logicor.h
26 * @ingroup CONSHDLRS
27 * @brief Constraint handler for logicor constraints \f$1^T x \ge 1\f$ (equivalent to set covering, but algorithms are suited for depth first search).
28 * @author Tobias Achterberg
29 * @author Michael Winkler
30 *
31 */
32
33/*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
34
35#ifndef __SCIP_CONS_LOGICOR_H__
36#define __SCIP_CONS_LOGICOR_H__
37
38
39#include "scip/def.h"
40#include "scip/type_cons.h"
41#include "scip/type_lp.h"
42#include "scip/type_retcode.h"
43#include "scip/type_scip.h"
44#include "scip/type_var.h"
45
46#ifdef __cplusplus
47extern "C" {
48#endif
49
50/** creates the handler for logic or constraints and includes it in SCIP
51 *
52 * @ingroup ConshdlrIncludes
53 * */
54SCIP_EXPORT
56 SCIP* scip /**< SCIP data structure */
57 );
58
59/**@addtogroup CONSHDLRS
60 *
61 * @{
62 *
63 * @name Logicor Constraints
64 *
65 * @{
66 *
67 * This constraint handler handles a special type of linear constraints, namely
68 * logic or constraints. These are equivalent to set covering constraints, but
69 * are handled by special algorithms which are better suited for depth first search.
70 * For a set of binary variables \f$x_i, i=1,\dots,n\f$, a logic or constraint has the form
71 * \f[
72 * \sum_{i=1}^n x_i \ge 1.
73 * \f]
74 */
75
76/** creates and captures a logic or constraint
77 *
78 * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()
79 */
80SCIP_EXPORT
82 SCIP* scip, /**< SCIP data structure */
83 SCIP_CONS** cons, /**< pointer to hold the created constraint */
84 const char* name, /**< name of constraint */
85 int nvars, /**< number of variables in the constraint */
86 SCIP_VAR** vars, /**< array with variables of constraint entries */
87 SCIP_Bool initial, /**< should the LP relaxation of constraint be in the initial LP?
88 * Usually set to TRUE. Set to FALSE for 'lazy constraints'. */
89 SCIP_Bool separate, /**< should the constraint be separated during LP processing?
90 * Usually set to TRUE. */
91 SCIP_Bool enforce, /**< should the constraint be enforced during node processing?
92 * TRUE for model constraints, FALSE for additional, redundant constraints. */
93 SCIP_Bool check, /**< should the constraint be checked for feasibility?
94 * TRUE for model constraints, FALSE for additional, redundant constraints. */
95 SCIP_Bool propagate, /**< should the constraint be propagated during node processing?
96 * Usually set to TRUE. */
97 SCIP_Bool local, /**< is constraint only valid locally?
98 * Usually set to FALSE. Has to be set to TRUE, e.g., for branching constraints. */
99 SCIP_Bool modifiable, /**< is constraint modifiable (subject to column generation)?
100 * Usually set to FALSE. In column generation applications, set to TRUE if pricing
101 * adds coefficients to this constraint. */
102 SCIP_Bool dynamic, /**< is constraint subject to aging?
103 * Usually set to FALSE. Set to TRUE for own cuts which
104 * are separated as constraints. */
105 SCIP_Bool removable, /**< should the relaxation be removed from the LP due to aging or cleanup?
106 * Usually set to FALSE. Set to TRUE for 'lazy constraints' and 'user cuts'. */
107 SCIP_Bool stickingatnode /**< should the constraint always be kept at the node where it was added, even
108 * if it may be moved to a more global node?
109 * Usually set to FALSE. Set to TRUE to for constraints that represent node data. */
110 );
111
112/** creates and captures a logicor constraint
113 * in its most basic version, i. e., all constraint flags are set to their basic value as explained for the
114 * method SCIPcreateConsLogicor(); all flags can be set via SCIPsetConsFLAGNAME-methods in scip.h
115 *
116 * @see SCIPcreateConsLogicor() for information about the basic constraint flag configuration
117 *
118 * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()
119 */
120SCIP_EXPORT
122 SCIP* scip, /**< SCIP data structure */
123 SCIP_CONS** cons, /**< pointer to hold the created constraint */
124 const char* name, /**< name of constraint */
125 int nvars, /**< number of variables in the constraint */
126 SCIP_VAR** vars /**< array with variables of constraint entries */
127 );
128
129/** adds coefficient in logic or constraint */
130SCIP_EXPORT
132 SCIP* scip, /**< SCIP data structure */
133 SCIP_CONS* cons, /**< logicor constraint */
134 SCIP_VAR* var /**< variable to add to the constraint */
135 );
136
137/** gets number of variables in logic or constraint */
138SCIP_EXPORT
140 SCIP* scip, /**< SCIP data structure */
141 SCIP_CONS* cons /**< constraint data */
142 );
143
144/** gets array of variables in logic or constraint */
145SCIP_EXPORT
147 SCIP* scip, /**< SCIP data structure */
148 SCIP_CONS* cons /**< constraint data */
149 );
150
151/** gets the dual solution of the logic or constraint in the current LP */
152SCIP_EXPORT
154 SCIP* scip, /**< SCIP data structure */
155 SCIP_CONS* cons /**< constraint data */
156 );
157
158/** gets the dual Farkas value of the logic or constraint in the current infeasible LP */
159SCIP_EXPORT
161 SCIP* scip, /**< SCIP data structure */
162 SCIP_CONS* cons /**< constraint data */
163 );
164
165/** returns the linear relaxation of the given logic or constraint; may return NULL if no LP row was yet created;
166 * the user must not modify the row!
167 */
168SCIP_EXPORT
170 SCIP* scip, /**< SCIP data structure */
171 SCIP_CONS* cons /**< constraint data */
172 );
173
174/** cleans up (multi-)aggregations and fixings from logicor constraints */
175SCIP_EXPORT
177 SCIP* scip, /**< SCIP data structure */
178 SCIP_Bool onlychecked, /**< should only checked constraints be cleaned up? */
179 int* naddconss, /**< pointer to count number of added (linear) constraints */
180 int* ndelconss, /**< pointer to count number of deleted (logicor) constraints */
181 int* nchgcoefs /**< pointer to count number of changed coefficients */
182 );
183
184/** @} */
185
186/** @} */
187
188#ifdef __cplusplus
189}
190#endif
191
192#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
int SCIPgetNVarsLogicor(SCIP *scip, SCIP_CONS *cons)
SCIP_Real SCIPgetDualsolLogicor(SCIP *scip, SCIP_CONS *cons)
SCIP_ROW * SCIPgetRowLogicor(SCIP *scip, SCIP_CONS *cons)
SCIP_RETCODE SCIPcleanupConssLogicor(SCIP *scip, SCIP_Bool onlychecked, int *naddconss, int *ndelconss, int *nchgcoefs)
SCIP_VAR ** SCIPgetVarsLogicor(SCIP *scip, SCIP_CONS *cons)
SCIP_RETCODE SCIPcreateConsBasicLogicor(SCIP *scip, SCIP_CONS **cons, const char *name, int nvars, SCIP_VAR **vars)
SCIP_RETCODE SCIPcreateConsLogicor(SCIP *scip, SCIP_CONS **cons, const char *name, int nvars, SCIP_VAR **vars, 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_Real SCIPgetDualfarkasLogicor(SCIP *scip, SCIP_CONS *cons)
SCIP_RETCODE SCIPaddCoefLogicor(SCIP *scip, SCIP_CONS *cons, SCIP_VAR *var)
SCIP_RETCODE SCIPincludeConshdlrLogicor(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