Scippy

SCIP

Solving Constraint Integer Programs

cons_orbitope.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) 2002-2017 Konrad-Zuse-Zentrum */
7 /* fuer Informationstechnik Berlin */
8 /* */
9 /* SCIP is distributed under the terms of the ZIB Academic License. */
10 /* */
11 /* You should have received a copy of the ZIB Academic License */
12 /* along with SCIP; see the file COPYING. If not email to scip@zib.de. */
13 /* */
14 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
15 
16 /**@file cons_orbitope.h
17  * @ingroup CONSHDLRS
18  * @brief constraint handler for (partitioning/packing) orbitope constraints w.r.t. the full symmetric group
19  * @author Timo Berthold
20  * @author Marc Pfetsch
21  *
22  */
23 
24 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
25 
26 #ifndef __SCIP_CONS_ORBITOPE_H__
27 #define __SCIP_CONS_ORBITOPE_H__
28 
29 #include "scip/scip.h"
30 
31 #ifdef __cplusplus
32 extern "C" {
33 #endif
34 
35 
36 /** creates the handler for orbitope constraints and includes it in SCIP
37  *
38  * @ingroup ConshdlrIncludes
39  */
40 extern
41 SCIP_RETCODE SCIPincludeConshdlrOrbitope(
42  SCIP* scip /**< SCIP data structure */
43  );
44 
45 /**@addtogroup CONSHDLRS
46  *
47  * @{
48  *
49  * @name Orbitope Constraints
50  *
51  * @{
52  *
53  * This constraint handler can be used to handle symmetries in certain 0/1-programs. The principle
54  * structure is that some variables can be ordered in matrix form, such that permuting columns does
55  * not change the validity and objective function value of a solution. That is, the symmetry group
56  * of the program contains the full symmetric group obtained by permuting the columns of this
57  * matrix. The variables in each row have to be contained in set packing or partitioning
58  * constraints.
59  *
60  * In more mathematical terms the structure has to be as follows: There are 0/1-variables
61  * \f$x_{ij}\f$, \f$i \in \{1, \dots, p\}\f$, \f$j \in \{1, \dots, q\}\f$. The variables are coupled
62  * through set packing or partitioning constraints:
63  * \f[
64  * \sum_{j = 1}^q x_{ij} \leq 1 \quad \mbox{or} \quad \sum_{j = 1}^q x_{ij} = 1 \quad \mbox{for all }i = 1, \ldots, p.
65  * \f]
66  * Permuting columns of \f$x\f$ does not change the validity and objective function value of any feasible solution.
67  */
68 
69 /** creates and captures a orbitope constraint
70  *
71  * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()
72  */
73 extern
74 SCIP_RETCODE SCIPcreateConsOrbitope(
75  SCIP* scip, /**< SCIP data structure */
76  SCIP_CONS** cons, /**< pointer to hold the created constraint */
77  const char* name, /**< name of constraint */
78  SCIP_VAR*** vars, /**< matrix of variables on which the symmetry acts */
79  SCIP_Bool ispart, /**< whether we deal with the partitioning case (packing otherwise) */
80  int nspcons, /**< number of set partitioning/packing constraints <=> p */
81  int nblocks, /**< number of symmetric variable blocks <=> q */
82  SCIP_Bool resolveprop, /**< should propagation be resolved? */
83  SCIP_Bool initial, /**< should the LP relaxation of constraint be in the initial LP?
84  * Usually set to TRUE. Set to FALSE for 'lazy constraints'. */
85  SCIP_Bool separate, /**< should the constraint be separated during LP processing?
86  * Usually set to TRUE. */
87  SCIP_Bool enforce, /**< should the constraint be enforced during node processing?
88  * TRUE for model constraints, FALSE for additional, redundant constraints. */
89  SCIP_Bool check, /**< should the constraint be checked for feasibility?
90  * TRUE for model constraints, FALSE for additional, redundant constraints. */
91  SCIP_Bool propagate, /**< should the constraint be propagated during node processing?
92  * Usually set to TRUE. */
93  SCIP_Bool local, /**< is constraint only valid locally?
94  * Usually set to FALSE. Has to be set to TRUE, e.g., for branching constraints. */
95  SCIP_Bool modifiable, /**< is constraint modifiable (subject to column generation)?
96  * Usually set to FALSE. In column generation applications, set to TRUE if pricing
97  * adds coefficients to this constraint. */
98  SCIP_Bool dynamic, /**< is constraint subject to aging?
99  * Usually set to FALSE. Set to TRUE for own cuts which
100  * are separated as constraints. */
101  SCIP_Bool removable, /**< should the relaxation be removed from the LP due to aging or cleanup?
102  * Usually set to FALSE. Set to TRUE for 'lazy constraints' and 'user cuts'. */
103  SCIP_Bool stickingatnode /**< should the constraint always be kept at the node where it was added, even
104  * if it may be moved to a more global node?
105  * Usually set to FALSE. Set to TRUE to for constraints that represent node data. */
106  );
107 
108 /** creates and captures an orbitope constraint
109  * in its most basic variant, i. e., with all constraint flags set to their default values, which can be set
110  * afterwards using SCIPsetConsFLAGNAME() in scip.h
111  *
112  * @see SCIPcreateConsOrbitope() for the default constraint flag configuration
113  *
114  * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()
115  */
116 extern
117 SCIP_RETCODE SCIPcreateConsBasicOrbitope(
118  SCIP* scip, /**< SCIP data structure */
119  SCIP_CONS** cons, /**< pointer to hold the created constraint */
120  const char* name, /**< name of constraint */
121  SCIP_VAR*** vars, /**< matrix of variables on which the symmetry acts */
122  SCIP_Bool ispart, /**< whether we deal with the partitioning case (packing otherwise) */
123  int nspcons, /**< number of set partitioning/packing constraints <=> p */
124  int nblocks, /**< number of symmetric variable blocks <=> q */
125  SCIP_Bool resolveprop /**< should propagation be resolved? */
126  );
127 
128 /* @} */
129 
130 /* @} */
131 
132 #ifdef __cplusplus
133 }
134 #endif
135 
136 #endif
SCIP_Var
Definition: struct_var.h:197
SCIP_RETCODE
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:53
SCIPcreateConsBasicOrbitope
SCIP_RETCODE SCIPcreateConsBasicOrbitope(SCIP *scip, SCIP_CONS **cons, const char *name, SCIP_VAR ***vars, SCIP_Bool ispart, int nspcons, int nblocks, SCIP_Bool resolveprop)
Definition: cons_orbitope.c:2448
SCIPincludeConshdlrOrbitope
SCIP_RETCODE SCIPincludeConshdlrOrbitope(SCIP *scip)
Definition: cons_orbitope.c:2302
SCIP_Cons
Definition: struct_cons.h:37
SCIP_Bool
#define SCIP_Bool
Definition: def.h:61
SCIPcreateConsOrbitope
SCIP_RETCODE SCIPcreateConsOrbitope(SCIP *scip, SCIP_CONS **cons, const char *name, SCIP_VAR ***vars, SCIP_Bool ispart, int nspcons, int nblocks, SCIP_Bool resolveprop, 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)
Definition: cons_orbitope.c:2344
scip.h
SCIP callable library.