/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /* */ /* This file is part of the program and library */ /* SCIP --- Solving Constraint Integer Programs */ /* */ /* Copyright (C) 2002-2020 Konrad-Zuse-Zentrum */ /* fuer Informationstechnik Berlin */ /* */ /* SCIP is distributed under the terms of the ZIB Academic License. */ /* */ /* You should have received a copy of the ZIB Academic License */ /* along with SCIP; see the file COPYING. If not visit scipopt.org. */ /* */ /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /**@file cons_varbound.h * @ingroup CONSHDLRS * @brief Constraint handler for variable bound constraints \f$lhs \leq x + c y \leq rhs\f$. * @author Tobias Achterberg * @author Timo Berthold * @author Michael Winkler * @author Gerald Gamrath * @author Stefan Heinz * */ /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/ #ifndef __SCIP_CONS_VARBOUND_H__ #define __SCIP_CONS_VARBOUND_H__ #include "scip/def.h" #include "scip/type_cons.h" #include "scip/type_lp.h" #include "scip/type_retcode.h" #include "scip/type_scip.h" #include "scip/type_var.h" #ifdef __cplusplus extern "C" { #endif /** creates the handler for variable bound constraints and includes it in SCIP * * @ingroup ConshdlrIncludes * */ SCIP_EXPORT SCIP_RETCODE SCIPincludeConshdlrVarbound( SCIP* scip /**< SCIP data structure */ ); /**@addtogroup CONSHDLRS * * @{ * * @name Variable Bound Constraints * * @{ * * This constraint handler handles a special type of linear constraints, namely variable bound constraints. * A variable bound constraint has the form * \f[ * lhs \leq x + c y \leq rhs * \f] * with coefficient \f$c \in Q\f$, \f$lhs\in Q \cup \{-\infty\}\f$, \f$rhs\in Q \cup \{\infty\}\f$, * and decision variables \f$x\f$ (non-binary) and \f$y\f$ (binary or integer). */ /** creates and captures a variable bound constraint: lhs <= x + c*y <= rhs * * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons() */ SCIP_EXPORT SCIP_RETCODE SCIPcreateConsVarbound( SCIP* scip, /**< SCIP data structure */ SCIP_CONS** cons, /**< pointer to hold the created constraint */ const char* name, /**< name of constraint */ SCIP_VAR* var, /**< variable x that has variable bound */ SCIP_VAR* vbdvar, /**< binary, integer or implicit integer bounding variable y */ SCIP_Real vbdcoef, /**< coefficient c of bounding variable y */ SCIP_Real lhs, /**< left hand side of variable bound inequality */ SCIP_Real rhs, /**< right hand side of variable bound inequality */ SCIP_Bool initial, /**< should the LP relaxation of constraint be in the initial LP? * Usually set to TRUE. Set to FALSE for 'lazy constraints'. */ SCIP_Bool separate, /**< should the constraint be separated during LP processing? * Usually set to TRUE. */ SCIP_Bool enforce, /**< should the constraint be enforced during node processing? * TRUE for model constraints, FALSE for additional, redundant constraints. */ SCIP_Bool check, /**< should the constraint be checked for feasibility? * TRUE for model constraints, FALSE for additional, redundant constraints. */ SCIP_Bool propagate, /**< should the constraint be propagated during node processing? * Usually set to TRUE. */ SCIP_Bool local, /**< is constraint only valid locally? * Usually set to FALSE. Has to be set to TRUE, e.g., for branching constraints. */ SCIP_Bool modifiable, /**< is constraint modifiable (subject to column generation)? * Usually set to FALSE. In column generation applications, set to TRUE if pricing * adds coefficients to this constraint. */ SCIP_Bool dynamic, /**< is constraint subject to aging? * Usually set to FALSE. Set to TRUE for own cuts which * are separated as constraints. */ SCIP_Bool removable, /**< should the relaxation be removed from the LP due to aging or cleanup? * Usually set to FALSE. Set to TRUE for 'lazy constraints' and 'user cuts'. */ SCIP_Bool stickingatnode /**< should the constraint always be kept at the node where it was added, even * if it may be moved to a more global node? * Usually set to FALSE. Set to TRUE to for constraints that represent node data. */ ); /** creates and captures a varbound constraint * in its most basic version, i. e., all constraint flags are set to their basic value as explained for the * method SCIPcreateConsVarbound(); all flags can be set via SCIPsetConsFLAGNAME-methods in scip.h * * @see SCIPcreateConsVarbound() for information about the basic constraint flag configuration * * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons() */ SCIP_EXPORT SCIP_RETCODE SCIPcreateConsBasicVarbound( SCIP* scip, /**< SCIP data structure */ SCIP_CONS** cons, /**< pointer to hold the created constraint */ const char* name, /**< name of constraint */ SCIP_VAR* var, /**< variable x that has variable bound */ SCIP_VAR* vbdvar, /**< binary, integer or implicit integer bounding variable y */ SCIP_Real vbdcoef, /**< coefficient c of bounding variable y */ SCIP_Real lhs, /**< left hand side of variable bound inequality */ SCIP_Real rhs /**< right hand side of variable bound inequality */ ); /** gets left hand side of variable bound constraint lhs <= x + c*y <= rhs */ SCIP_EXPORT SCIP_Real SCIPgetLhsVarbound( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint data */ ); /** gets right hand side of variable bound constraint lhs <= x + c*y <= rhs */ SCIP_EXPORT SCIP_Real SCIPgetRhsVarbound( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint data */ ); /** gets bounded variable x of variable bound constraint lhs <= x + c*y <= rhs */ SCIP_EXPORT SCIP_VAR* SCIPgetVarVarbound( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint data */ ); /** gets bounding variable y of variable bound constraint lhs <= x + c*y <= rhs */ SCIP_EXPORT SCIP_VAR* SCIPgetVbdvarVarbound( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint data */ ); /** gets bound coefficient c of variable bound constraint lhs <= x + c*y <= rhs */ SCIP_EXPORT SCIP_Real SCIPgetVbdcoefVarbound( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint data */ ); /** gets the dual solution of the variable bound constraint in the current LP */ SCIP_EXPORT SCIP_Real SCIPgetDualsolVarbound( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint data */ ); /** gets the dual Farkas value of the variable bound constraint in the current infeasible LP */ SCIP_EXPORT SCIP_Real SCIPgetDualfarkasVarbound( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint data */ ); /** returns the linear relaxation of the given variable bound constraint; may return NULL if no LP row was yet created; * the user must not modify the row! */ SCIP_EXPORT SCIP_ROW* SCIPgetRowVarbound( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint data */ ); /** cleans up (multi-)aggregations and fixings from varbound constraints */ SCIP_EXPORT SCIP_RETCODE SCIPcleanupConssVarbound( SCIP* scip, /**< SCIP data structure */ SCIP_Bool onlychecked, /**< should only checked constraints be cleaned up? */ SCIP_Bool* infeasible, /**< pointer to return whether the problem was detected to be infeasible */ int* naddconss, /**< pointer to count number of added (linear) constraints */ int* ndelconss, /**< pointer to count number of deleted (varbound) constraints */ int* nchgbds /**< pointer to count number of bound changes */ ); /** @} */ /** @} */ #ifdef __cplusplus } #endif #endif