/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /* */ /* This file is part of the program and library */ /* SCIP --- Solving Constraint Integer Programs */ /* */ /* Copyright 2002-2022 Zuse Institute Berlin */ /* */ /* Licensed under the Apache License, Version 2.0 (the "License"); */ /* you may not use this file except in compliance with the License. */ /* You may obtain a copy of the License at */ /* */ /* http://www.apache.org/licenses/LICENSE-2.0 */ /* */ /* Unless required by applicable law or agreed to in writing, software */ /* distributed under the License is distributed on an "AS IS" BASIS, */ /* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. */ /* See the License for the specific language governing permissions and */ /* limitations under the License. */ /* */ /* You should have received a copy of the Apache-2.0 license */ /* along with SCIP; see the file LICENSE. If not visit scipopt.org. */ /* */ /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /**@file cons_linear.h * @ingroup CONSHDLRS * @brief Constraint handler for linear constraints in their most general form, \f$lhs <= a^T x <= rhs\f$. * @author Tobias Achterberg * @author Timo Berthold * @author Marc Pfetsch * @author Kati Wolter * */ /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/ #ifndef __SCIP_CONS_LINEAR_H__ #define __SCIP_CONS_LINEAR_H__ #include "scip/def.h" #include "scip/type_cons.h" #include "scip/type_lp.h" #include "scip/type_misc.h" #include "scip/type_retcode.h" #include "scip/type_scip.h" #include "scip/type_sol.h" #include "scip/type_var.h" #ifdef __cplusplus extern "C" { #endif /* * constraint specific interface methods */ /** creates the handler for linear constraints and includes it in SCIP * * @ingroup ConshdlrIncludes * */ SCIP_EXPORT SCIP_RETCODE SCIPincludeConshdlrLinear( SCIP* scip /**< SCIP data structure */ ); /**@addtogroup CONSHDLRS * * @{ * * @name Linear Constraints * * This constraint handler handles linear constraints in their most general form. That is, * \f[ * lhs \leq \sum_{i=1}^n a_i x_i \leq rhs * \f] * with \f$a_i \in Q, i = 1,\dots,n\f$, \f$lhs\in Q \cup \{-\infty\}\f$, \f$rhs\in Q \cup \{\infty\}\f$, * and decision variables \f$x_i, i = 1,\dots,n\f$ which can be binary, integer, or continuous. * * Furthermore, this header offers the upgrade functionality of a general linear constraint into a more specific * constraint, such as a knapsack constraint, via SCIP_DECL_LINCONSUPGD() and SCIPincludeLinconsUpgrade() * * @{ */ typedef struct SCIP_LinConsUpgrade SCIP_LINCONSUPGRADE; /**< linear constraint update method */ /** upgrading method for linear constraints into more specific constraints * * input: * - scip : SCIP main data structure * - cons : the linear constraint to upgrade * - nvars : number of variables in the constraint * - vars : array with constraint variables * - vals : array with constraint coefficients * - lhs : left hand side of linear constraint * - rhs : right hand side of linear constraint * - nposbin : number of binary variables with positive coefficient * - nnegbin : number of binary variables with negative coefficient * - nposint : number of integer variables with positive coefficient * - nnegint : number of integer variables with negative coefficient * - nposimpl : number of implicit integer variables with positive coefficient (including implicit binary variables) * - nnegimpl : number of implicit integer variables with negative coefficient (including implicit binary variables) * - nposimplbin : number of implicit binary variables with positive coefficient * - nnegimplbin : number of implicit binary variables with negative coefficient * - nposcont : number of continuous variables with positive coefficient * - nnegcont : number of continuous variables with negative coefficient * - ncoeffspone : number of +1 coefficients * - ncoeffsnone : number of -1 coefficients * - ncoeffspint : number of positive integral coefficients other than +1 * - ncoeffsnint : number of negative integral coefficients other than -1 * - ncoeffspfrac : number of positive fractional coefficients * - ncoeffsnfrac : number of negative fractional coefficients * - poscoeffsum : sum of all positive coefficients * - negcoeffsum : sum of all negative coefficients * - integral : TRUE iff constraints activity value is always integral * - upgdcons : pointer to store the upgraded constraint */ #define SCIP_DECL_LINCONSUPGD(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONS* cons, int nvars, SCIP_VAR** vars, SCIP_Real* vals, SCIP_Real lhs, SCIP_Real rhs, \ int nposbin, int nnegbin, int nposint, int nnegint, int nposimpl, int nnegimpl, int nposimplbin, int nnegimplbin, int nposcont, int nnegcont, \ int ncoeffspone, int ncoeffsnone, int ncoeffspint, int ncoeffsnint, int ncoeffspfrac, int ncoeffsnfrac, \ SCIP_Real poscoeffsum, SCIP_Real negcoeffsum, SCIP_Bool integral, SCIP_CONS** upgdcons) /** includes a linear constraint update method into the linear constraint handler */ SCIP_EXPORT SCIP_RETCODE SCIPincludeLinconsUpgrade( SCIP* scip, /**< SCIP data structure */ SCIP_DECL_LINCONSUPGD((*linconsupgd)), /**< method to call for upgrading linear constraint */ int priority, /**< priority of upgrading method */ const char* conshdlrname /**< name of the constraint handler */ ); /** creates and captures a linear constraint * * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons() */ SCIP_EXPORT SCIP_RETCODE SCIPcreateConsLinear( SCIP* scip, /**< SCIP data structure */ SCIP_CONS** cons, /**< pointer to hold the created constraint */ const char* name, /**< name of constraint */ int nvars, /**< number of nonzeros in the constraint */ SCIP_VAR** vars, /**< array with variables of constraint entries */ SCIP_Real* vals, /**< array with coefficients of constraint entries */ 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 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 linear constraint * in its most basic version, i. e., all constraint flags are set to their basic value as explained for the * method SCIPcreateConsLinear(); all flags can be set via SCIPsetConsFLAGNAME-methods in scip.h * * @see SCIPcreateConsLinear() 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 SCIPcreateConsBasicLinear( SCIP* scip, /**< SCIP data structure */ SCIP_CONS** cons, /**< pointer to hold the created constraint */ const char* name, /**< name of constraint */ int nvars, /**< number of nonzeros in the constraint */ SCIP_VAR** vars, /**< array with variables of constraint entries */ SCIP_Real* vals, /**< array with coefficients of constraint entries */ SCIP_Real lhs, /**< left hand side of constraint */ SCIP_Real rhs /**< right hand side of constraint */ ); /** creates by copying and captures a linear constraint */ SCIP_EXPORT SCIP_RETCODE SCIPcopyConsLinear( SCIP* scip, /**< target SCIP data structure */ SCIP_CONS** cons, /**< pointer to store the created target constraint */ SCIP* sourcescip, /**< source SCIP data structure */ const char* name, /**< name of constraint */ int nvars, /**< number of variables in source variable array */ SCIP_VAR** sourcevars, /**< source variables of the linear constraints */ SCIP_Real* sourcecoefs, /**< coefficient array of the linear constraint, or NULL if all coefficients are one */ SCIP_Real lhs, /**< left hand side of the linear constraint */ SCIP_Real rhs, /**< right hand side of the linear constraint */ SCIP_HASHMAP* varmap, /**< a SCIP_HASHMAP mapping variables of the source SCIP to corresponding * variables of the target SCIP */ SCIP_HASHMAP* consmap, /**< a hashmap to store the mapping of source constraints to the corresponding * target constraints */ SCIP_Bool initial, /**< should the LP relaxation of constraint be in the initial LP? */ SCIP_Bool separate, /**< should the constraint be separated during LP processing? */ SCIP_Bool enforce, /**< should the constraint be enforced during node processing? */ SCIP_Bool check, /**< should the constraint be checked for feasibility? */ SCIP_Bool propagate, /**< should the constraint be propagated during node processing? */ SCIP_Bool local, /**< is constraint only valid locally? */ SCIP_Bool modifiable, /**< is constraint modifiable (subject to column generation)? */ SCIP_Bool dynamic, /**< is constraint subject to aging? */ SCIP_Bool removable, /**< should the relaxation be removed from the LP due to aging or cleanup? */ 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? */ SCIP_Bool global, /**< create a global or a local copy? */ SCIP_Bool* valid /**< pointer to store if the copying was valid */ ); /** adds coefficient to linear constraint (if it is not zero) */ SCIP_EXPORT SCIP_RETCODE SCIPaddCoefLinear( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons, /**< constraint data */ SCIP_VAR* var, /**< variable of constraint entry */ SCIP_Real val /**< coefficient of constraint entry */ ); /** changes coefficient of variable in linear constraint; deletes the variable if coefficient is zero; adds variable if * not yet contained in the constraint * * @note This method may only be called during problem creation stage for an original constraint and variable. * * @note This method requires linear time to search for occurences of the variable in the constraint data. */ SCIP_EXPORT SCIP_RETCODE SCIPchgCoefLinear( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons, /**< constraint data */ SCIP_VAR* var, /**< variable of constraint entry */ SCIP_Real val /**< new coefficient of constraint entry */ ); /** deletes variable from linear constraint * * @note This method may only be called during problem creation stage for an original constraint and variable. * * @note This method requires linear time to search for occurences of the variable in the constraint data. */ SCIP_EXPORT SCIP_RETCODE SCIPdelCoefLinear( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons, /**< constraint data */ SCIP_VAR* var /**< variable of constraint entry */ ); /** gets left hand side of linear constraint */ SCIP_EXPORT SCIP_Real SCIPgetLhsLinear( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint data */ ); /** gets right hand side of linear constraint */ SCIP_EXPORT SCIP_Real SCIPgetRhsLinear( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint data */ ); /** changes left hand side of linear constraint */ SCIP_EXPORT SCIP_RETCODE SCIPchgLhsLinear( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons, /**< constraint data */ SCIP_Real lhs /**< new left hand side */ ); /** changes right hand side of linear constraint */ SCIP_EXPORT SCIP_RETCODE SCIPchgRhsLinear( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons, /**< constraint data */ SCIP_Real rhs /**< new right hand side */ ); /** gets the number of variables in the linear constraint */ SCIP_EXPORT int SCIPgetNVarsLinear( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint data */ ); /** gets the array of variables in the linear constraint; the user must not modify this array! */ SCIP_EXPORT SCIP_VAR** SCIPgetVarsLinear( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint data */ ); /** gets the array of coefficient values in the linear constraint; the user must not modify this array! */ SCIP_EXPORT SCIP_Real* SCIPgetValsLinear( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint data */ ); /** gets the activity of the linear constraint in the given solution * * @note if the solution contains values at infinity, this method will return SCIP_INVALID in case the activity * comprises positive and negative infinity contributions */ SCIP_EXPORT SCIP_Real SCIPgetActivityLinear( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons, /**< constraint data */ SCIP_SOL* sol /**< solution, or NULL to use current node's solution */ ); /** gets the feasibility of the linear constraint in the given solution */ SCIP_EXPORT SCIP_Real SCIPgetFeasibilityLinear( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons, /**< constraint data */ SCIP_SOL* sol /**< solution, or NULL to use current node's solution */ ); /** gets the dual solution of the linear constraint in the current LP */ SCIP_EXPORT SCIP_Real SCIPgetDualsolLinear( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint data */ ); /** gets the dual Farkas value of the linear constraint in the current infeasible LP */ SCIP_EXPORT SCIP_Real SCIPgetDualfarkasLinear( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint data */ ); /** returns the linear relaxation of the given linear constraint; may return NULL if no LP row was yet created; * the user must not modify the row! */ SCIP_EXPORT SCIP_ROW* SCIPgetRowLinear( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint data */ ); /** tries to automatically convert a linear constraint into a more specific and more specialized constraint */ SCIP_EXPORT SCIP_RETCODE SCIPupgradeConsLinear( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons, /**< source constraint to try to convert */ SCIP_CONS** upgdcons /**< pointer to store upgraded constraint, or NULL if not successful */ ); /** performs linear constraint type classification as used for MIPLIB * * iterates through all linear constraints and stores relevant statistics in the linear constraint statistics \p linconsstats. * * @note only constraints are iterated that belong to the linear constraint handler. If the problem has been presolved already, * constraints that were upgraded to more special types such as, e.g., varbound constraints, will not be shown correctly anymore. * Similarly, if specialized constraints were created through the API, these are currently not present. */ SCIP_EXPORT SCIP_RETCODE SCIPclassifyConstraintTypesLinear( SCIP* scip, /**< SCIP data structure */ SCIP_LINCONSSTATS* linconsstats /**< linear constraint type classification */ ); /** cleans up (multi-)aggregations and fixings from linear constraints */ SCIP_EXPORT SCIP_RETCODE SCIPcleanupConssLinear( 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 */ ); /** @} */ /** @} */ #ifdef __cplusplus } #endif #endif