/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /* */ /* 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_bivariate.h * @ingroup CONSHDLRS * @brief constraint handler for bivariate nonlinear constraints \f$\textrm{lhs} \leq f(x,y) + c z \leq \textrm{rhs}\f$ * @author Martin Ballerstein * @author Dennis Michaels * @author Stefan Vigerske * */ /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/ #ifndef __SCIP_CONS_BIVARIATE_H__ #define __SCIP_CONS_BIVARIATE_H__ #include "scip/def.h" #include "scip/type_cons.h" #include "nlpi/type_expr.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 bivariate constraints and includes it in SCIP * * @ingroup ConshdlrIncludes * */ SCIP_EXPORT SCIP_RETCODE SCIPincludeConshdlrBivariate( SCIP* scip /**< SCIP data structure */ ); /**@addtogroup CONSHDLRS * * @{ * * @name Bivariate Constraints * * This constraint handler handles constraints of the form * \f[ * \textrm{lhs} \leq f(x,y) + c z \leq \textrm{rhs} * \f] * for a bivariate nonlinear function \f$f(x,y)\f$ (given as expression tree) that has * a fixed convexity behaviour, that is, \f$f(x,y)\f$ has to be either jointly convex in \f$(x,y)\f$, * or convex in \f$x\f$ and concave in \f$y\f$, * or convex in \f$x\f$ and convex in \f$y\f$, but indefinite w.r.t. \f$(x,y)\f$. * See also * * @par * Martin Ballerstein, Dennis Michaels, and Stefan Vigerske@n * Linear Underestimators for bivariate functions with a fixed convexity behavior@n * ZIB Report 13-02, 2013. http://opus4.kobv.de/opus4-zib/frontdoor/index/index/docId/1764 * * @{ */ typedef enum { SCIP_BIVAR_ALLCONVEX = 0, /* f(x,y) is convex */ SCIP_BIVAR_1CONVEX_INDEFINITE = 1, /* f(x,y) is 1-convex and indefinite */ SCIP_BIVAR_CONVEX_CONCAVE = 2, /* f(x,y) is convex in x and concave in y */ SCIP_BIVAR_UNKNOWN = 3 /* unknown */ } SCIP_BIVAR_CONVEXITY; /** creates and captures a bivariate constraint * * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons() */ SCIP_EXPORT SCIP_RETCODE SCIPcreateConsBivariate( SCIP* scip, /**< SCIP data structure */ SCIP_CONS** cons, /**< pointer to hold the created constraint */ const char* name, /**< name of constraint */ SCIP_EXPRTREE* f, /**< expression tree specifying bivariate function f(x,y) */ SCIP_BIVAR_CONVEXITY convextype, /**< kind of convexity of f(x,y) */ SCIP_VAR* z, /**< linear variable in constraint */ SCIP_Real zcoef, /**< coefficient of linear variable */ SCIP_Real lhs, /**< left hand side of constraint */ SCIP_Real rhs, /**< right hand side of constraint */ 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 seperated 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 an absolute power constraint * in its most basic version, i. e., all constraint flags are set to their basic value as explained for the * method SCIPcreateConsBivariate(); all flags can be set via SCIPconsSetFLAGNAME-methods in cons.h * * @see SCIPcreateConsBivariate() 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 SCIPcreateConsBasicBivariate( SCIP* scip, /**< SCIP data structure */ SCIP_CONS** cons, /**< pointer to hold the created constraint */ const char* name, /**< name of constraint */ SCIP_EXPRTREE* f, /**< expression tree specifying bivariate function f(x,y) */ SCIP_BIVAR_CONVEXITY convextype, /**< kind of convexity of f(x,y) */ SCIP_VAR* z, /**< linear variable in constraint */ SCIP_Real zcoef, /**< coefficient of linear variable */ SCIP_Real lhs, /**< left hand side of constraint */ SCIP_Real rhs /**< right hand side of constraint */ ); /** gets the linear variable of a bivariate constraint, or NULL if no such variable */ SCIP_EXPORT SCIP_VAR* SCIPgetLinearVarBivariate( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint */ ); /** gets the coefficients of the linear variable of a bivariate constraint */ SCIP_EXPORT SCIP_Real SCIPgetLinearCoefBivariate( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint */ ); /** gets the expression tree of a bivariate constraint */ SCIP_EXPORT SCIP_EXPRTREE* SCIPgetExprtreeBivariate( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint */ ); /** gets the left hand side of a bivariate constraint */ SCIP_EXPORT SCIP_Real SCIPgetLhsBivariate( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint */ ); /** gets the right hand side of a bivariate constraint */ SCIP_EXPORT SCIP_Real SCIPgetRhsBivariate( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint */ ); /** @} */ /** @} */ #ifdef __cplusplus } #endif #endif