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) 2002-2014 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  * This constraint handler can be used to handle symmetries in certain 0/1-programs. The principle 23  * structure is that some variables can be ordered in matrix form, such that permuting columns does 24  * not change the validity and objective function value of a solution. That is, the symmetry group 25  * of the program contains the full symmetric group obtained by permuting the columns of this 26  * matrix. The variables in each row have to be contained in set packing or partitioning 27  * constraints. 28  * 29  * In more mathematical terms the structure has to be as follows: There are 0/1-variables 30  * \f$x_{ij}\f$, \f$i \in \{1, \dots, p\}\f$, \f$j \in \{1, \dots, q\}\f$. The variables are coupled 31  * through set packing or partitioning constraints: 32  * \f[ 33  * \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. 34  * \f] 35  * Permuting columns of \f$x\f$ does not change the validity and objective function value of any feasible solution. 36  */ 37  38 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/ 39  40 #ifndef __SCIP_CONS_ORBITOPE_H__ 41 #define __SCIP_CONS_ORBITOPE_H__ 42  43 #include "scip/scip.h" 44  45 #ifdef __cplusplus 46 extern "C" { 47 #endif 48  49  50 /** creates the handler for orbitope constraints and includes it in SCIP */ 51 extern 53  SCIP* scip /**< SCIP data structure */ 54  ); 55  56 /** creates and captures a orbitope constraint 57  * 58  * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons() 59  */ 60 extern 62  SCIP* scip, /**< SCIP data structure */ 63  SCIP_CONS** cons, /**< pointer to hold the created constraint */ 64  const char* name, /**< name of constraint */ 65  SCIP_VAR*** vars, /**< matrix of variables on which the symmetry acts */ 66  SCIP_Bool ispart, /**< whether we deal with the partitioning case (packing otherwise) */ 67  int nspcons, /**< number of set partitioning/packing constraints <=> p */ 68  int nblocks, /**< number of symmetric variable blocks <=> q */ 69  SCIP_Bool resolveprop, /**< should propagation be resolved? */ 70  SCIP_Bool initial, /**< should the LP relaxation of constraint be in the initial LP? 71  * Usually set to TRUE. Set to FALSE for 'lazy constraints'. */ 72  SCIP_Bool separate, /**< should the constraint be separated during LP processing? 73  * Usually set to TRUE. */ 74  SCIP_Bool enforce, /**< should the constraint be enforced during node processing? 75  * TRUE for model constraints, FALSE for additional, redundant constraints. */ 76  SCIP_Bool check, /**< should the constraint be checked for feasibility? 77  * TRUE for model constraints, FALSE for additional, redundant constraints. */ 78  SCIP_Bool propagate, /**< should the constraint be propagated during node processing? 79  * Usually set to TRUE. */ 80  SCIP_Bool local, /**< is constraint only valid locally? 81  * Usually set to FALSE. Has to be set to TRUE, e.g., for branching constraints. */ 82  SCIP_Bool modifiable, /**< is constraint modifiable (subject to column generation)? 83  * Usually set to FALSE. In column generation applications, set to TRUE if pricing 84  * adds coefficients to this constraint. */ 85  SCIP_Bool dynamic, /**< is constraint subject to aging? 86  * Usually set to FALSE. Set to TRUE for own cuts which 87  * are separated as constraints. */ 88  SCIP_Bool removable, /**< should the relaxation be removed from the LP due to aging or cleanup? 89  * Usually set to FALSE. Set to TRUE for 'lazy constraints' and 'user cuts'. */ 90  SCIP_Bool stickingatnode /**< should the constraint always be kept at the node where it was added, even 91  * if it may be moved to a more global node? 92  * Usually set to FALSE. Set to TRUE to for constraints that represent node data. */ 93  ); 94  95 /** creates and captures an orbitope constraint 96  * in its most basic variant, i. e., with all constraint flags set to their default values, which can be set 97  * afterwards using SCIPsetConsFLAGNAME() in scip.h 98  * 99  * @see SCIPcreateConsOrbitope() for the default constraint flag configuration 100  * 101  * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons() 102  */ 103 extern 105  SCIP* scip, /**< SCIP data structure */ 106  SCIP_CONS** cons, /**< pointer to hold the created constraint */ 107  const char* name, /**< name of constraint */ 108  SCIP_VAR*** vars, /**< matrix of variables on which the symmetry acts */ 109  SCIP_Bool ispart, /**< whether we deal with the partitioning case (packing otherwise) */ 110  int nspcons, /**< number of set partitioning/packing constraints <=> p */ 111  int nblocks, /**< number of symmetric variable blocks <=> q */ 112  SCIP_Bool resolveprop /**< should propagation be resolved? */ 113  ); 114  115 #ifdef __cplusplus 116 } 117 #endif 118  119 #endif 120  Generated on Wed Apr 2 2014 for SCIP Doxygen Documentation by doxygen (1.8.2) © 2020 by Zuse Institute Berlin (ZIB), Imprint designed with Bootstrap