/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/* */
/* 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