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_undercover.h 26 * @ingroup PRIMALHEURISTICS 27 * @brief Undercover primal heuristic for MINLPs 28 * @author Timo Berthold 29 * @author Ambros Gleixner 30 * 31 * The undercover heuristic is designed for mixed-integer nonlinear programs and tries to fix a subset of variables such 32 * as to make each constraint linear or convex. For this purpose it solves a binary program to automatically determine 33 * the minimum number of variable fixings necessary. As fixing values, we use values from the LP relaxation, the NLP 34 * relaxation, or the incumbent solution. 35 */ 36 37 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/ 38 39 #ifndef __SCIP_HEUR_UNDERCOVER_H__ 40 #define __SCIP_HEUR_UNDERCOVER_H__ 41 42 #include "scip/def.h" 43 #include "scip/type_retcode.h" 44 #include "scip/type_scip.h" 45 #include "scip/type_var.h" 46 47 #ifdef __cplusplus 48 extern "C" { 49 #endif 50 51 /** creates the undercover primal heuristic and includes it in SCIP 52 * 53 * @ingroup PrimalHeuristicIncludes 54 */ 55 SCIP_EXPORT 56 SCIP_RETCODE SCIPincludeHeurUndercover( 57 SCIP* scip /**< SCIP data structure */ 58 ); 59 60 /**@addtogroup PRIMALHEURISTICS 61 * 62 * @{ 63 */ 64 65 /** computes a minimal set of covering variables */ 66 SCIP_EXPORT 67 SCIP_RETCODE SCIPcomputeCoverUndercover( 68 SCIP* scip, /**< SCIP data structure */ 69 int* coversize, /**< size of the computed cover */ 70 SCIP_VAR** cover, /**< pointer to store the variables (of the original SCIP) in the computed cover 71 * (should be ready to hold SCIPgetNVars(scip) entries) */ 72 SCIP_Real timelimit, /**< time limit */ 73 SCIP_Real memorylimit, /**< memory limit */ 74 SCIP_Real objlimit, /**< objective limit: upper bound on coversize */ 75 SCIP_Bool globalbounds, /**< should global bounds on variables be used instead of local bounds at focus node? */ 76 SCIP_Bool onlyconvexify, /**< should we only fix/dom.red. variables creating nonconvexity? */ 77 SCIP_Bool coverand, /**< should and constraints be covered (or just copied)? */ 78 SCIP_Bool coverbd, /**< should bounddisjunction constraints be covered (or just copied)? */ 79 SCIP_Bool coverind, /**< should indicator constraints be covered (or just copied)? */ 80 SCIP_Bool covernl, /**< should nonlinear constraints be covered (or just copied)? */ 81 char coveringobj, /**< objective function of the covering problem ('b'ranching status, 82 * influenced nonlinear 'c'onstraints/'t'erms, 'd'omain size, 'l'ocks, 83 * 'm'in of up/down locks, 'u'nit penalties, constraint 'v'iolation) */ 84 SCIP_Bool* success /**< feasible cover found? */ 85 ); 86 87 /** @} */ 88 89 #ifdef __cplusplus 90 } 91 #endif 92 93 #endif 94