1 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ 2 /* */ 3 /* This file is part of the program and library */ 4 /* SCIP --- Solving Constraint Integer Programs */ 5 /* */ 6 /* Copyright (c) 2002-2023 Zuse Institute Berlin (ZIB) */ 7 /* */ 8 /* Licensed under the Apache License, Version 2.0 (the "License"); */ 9 /* you may not use this file except in compliance with the License. */ 10 /* You may obtain a copy of the License at */ 11 /* */ 12 /* http://www.apache.org/licenses/LICENSE-2.0 */ 13 /* */ 14 /* Unless required by applicable law or agreed to in writing, software */ 15 /* distributed under the License is distributed on an "AS IS" BASIS, */ 16 /* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. */ 17 /* See the License for the specific language governing permissions and */ 18 /* limitations under the License. */ 19 /* */ 20 /* You should have received a copy of the Apache-2.0 license */ 21 /* along with SCIP; see the file LICENSE. If not visit scipopt.org. */ 22 /* */ 23 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ 24 25 /**@file heur_proximity.h 26 * @ingroup PRIMALHEURISTICS 27 * @brief improvement heuristic which uses an auxiliary objective instead of the original objective function which 28 * is itself added as a constraint to a sub-SCIP instance. The heuristic was presented by Matteo Fischetti 29 * and Michele Monaci 30 * @author Gregor Hendel 31 */ 32 33 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/ 34 35 #ifndef __SCIP_HEUR_PROXIMITY_H__ 36 #define __SCIP_HEUR_PROXIMITY_H__ 37 38 #include "scip/def.h" 39 #include "scip/type_heur.h" 40 #include "scip/type_result.h" 41 #include "scip/type_retcode.h" 42 #include "scip/type_scip.h" 43 44 #ifdef __cplusplus 45 extern "C" { 46 #endif 47 48 /** creates the proximity primal heuristic and includes it in SCIP 49 * 50 * @ingroup PrimalHeuristicIncludes 51 */ 52 SCIP_EXPORT 53 SCIP_RETCODE SCIPincludeHeurProximity( 54 SCIP* scip /**< SCIP data structure */ 55 ); 56 57 /**@addtogroup PRIMALHEURISTICS 58 * 59 * @{ 60 */ 61 62 /** main procedure of the proximity heuristic, creates and solves a sub-SCIP 63 * 64 * @note the method can be applied in an iterative way, keeping the same subscip in between. If the @p freesubscip 65 * parameter is set to FALSE, the heuristic will keep the subscip data structures. Always set this parameter 66 * to TRUE, or call SCIPdeleteSubproblemProximity() afterwards 67 */ 68 SCIP_EXPORT 69 SCIP_RETCODE SCIPapplyProximity( 70 SCIP* scip, /**< original SCIP data structure */ 71 SCIP_HEUR* heur, /**< heuristic data structure */ 72 SCIP_RESULT* result, /**< result data structure */ 73 SCIP_Real minimprove, /**< factor by which proximity should at least improve the incumbent */ 74 SCIP_Longint nnodes, /**< node limit for the subproblem */ 75 SCIP_Longint nlpiters, /**< LP iteration limit for the subproblem */ 76 SCIP_Longint* nusednodes, /**< pointer to store number of used nodes in subscip */ 77 SCIP_Longint* nusedlpiters, /**< pointer to store number of used LP iterations in subscip */ 78 SCIP_Bool freesubscip /**< should the created sub-MIP be freed at the end of the method? */ 79 ); 80 81 /** frees the sub-MIP created by proximity */ 82 SCIP_EXPORT 83 SCIP_RETCODE SCIPdeleteSubproblemProximity( 84 SCIP* scip /** SCIP data structure */ 85 ); 86 87 /** @} */ 88 89 #ifdef __cplusplus 90 } 91 #endif 92 93 #endif 94