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 prop_probing.h 26 * @ingroup PROPAGATORS 27 * @brief probing propagator 28 * @author Tobias Achterberg 29 */ 30 31 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/ 32 33 #ifndef __SCIP_PROP_PROBING_H__ 34 #define __SCIP_PROP_PROBING_H__ 35 36 #include "scip/def.h" 37 #include "scip/type_lp.h" 38 #include "scip/type_retcode.h" 39 #include "scip/type_scip.h" 40 #include "scip/type_var.h" 41 42 #ifdef __cplusplus 43 extern "C" { 44 #endif 45 46 /** creates the probing propagator and includes it in SCIP 47 * 48 * @ingroup PropagatorIncludes 49 */ 50 SCIP_EXPORT 51 SCIP_RETCODE SCIPincludePropProbing( 52 SCIP* scip /**< SCIP data structure */ 53 ); 54 55 /**@addtogroup PROPAGATORS 56 * 57 * @{ 58 */ 59 60 /** applies and evaluates probing of a single variable in the given direction and bound */ 61 SCIP_EXPORT 62 SCIP_RETCODE SCIPapplyProbingVar( 63 SCIP* scip, /**< SCIP data structure */ 64 SCIP_VAR** vars, /**< problem variables */ 65 int nvars, /**< number of problem variables */ 66 int probingpos, /**< variable number to apply probing on */ 67 SCIP_BOUNDTYPE boundtype, /**< which bound should be changed */ 68 SCIP_Real bound, /**< which bound should be set */ 69 int maxproprounds, /**< maximal number of propagation rounds (-1: no limit, 0: parameter settings) */ 70 SCIP_Real* impllbs, /**< array to store lower bounds after applying implications and cliques */ 71 SCIP_Real* implubs, /**< array to store upper bounds after applying implications and cliques */ 72 SCIP_Real* proplbs, /**< array to store lower bounds after full propagation */ 73 SCIP_Real* propubs, /**< array to store upper bounds after full propagation */ 74 SCIP_Bool* cutoff /**< pointer to store whether the probing direction is infeasible */ 75 ); 76 77 /** analyses boundchanges resulting from probing on a variable and performs deduced fixations, aggregations, and domain tightenings 78 * 79 * Given a variable probingvar with domain [l,u] and bound tightening results from reducing the 80 * domain once to [l,leftub] and once to [rightlb,u], the method computes and applies resulting 81 * variable fixations, aggregations, implications, and bound changes. Variable probingvar does not 82 * need to be binary. The whole domain of probingvar need to be covered by the left and right 83 * branches, i.e., we assume leftub >= rightlb for continuous variables or floor(leftub) >= 84 * ceil(rightlb)-1 for discrete variables. Bounds after applying implications and cliques do not 85 * need to be provided, but if they are omitted and probingvar is a binary variable, then already 86 * existing implications may be added. 87 */ 88 SCIP_EXPORT 89 SCIP_RETCODE SCIPanalyzeDeductionsProbing( 90 SCIP* scip, /**< SCIP data structure */ 91 SCIP_VAR* probingvar, /**< the probing variable */ 92 SCIP_Real leftub, /**< upper bound of probing variable in left branch */ 93 SCIP_Real rightlb, /**< lower bound of probing variable in right branch */ 94 int nvars, /**< number of variables which bound changes should be analyzed */ 95 SCIP_VAR** vars, /**< variables which bound changes should be analyzed */ 96 SCIP_Real* leftimpllbs, /**< lower bounds after applying implications and cliques in left branch, or NULL */ 97 SCIP_Real* leftimplubs, /**< upper bounds after applying implications and cliques in left branch, or NULL */ 98 SCIP_Real* leftproplbs, /**< lower bounds after applying domain propagation in left branch */ 99 SCIP_Real* leftpropubs, /**< upper bounds after applying domain propagation in left branch */ 100 SCIP_Real* rightimpllbs, /**< lower bounds after applying implications and cliques in right branch, or NULL */ 101 SCIP_Real* rightimplubs, /**< upper bounds after applying implications and cliques in right branch, or NULL */ 102 SCIP_Real* rightproplbs, /**< lower bounds after applying domain propagation in right branch */ 103 SCIP_Real* rightpropubs, /**< upper bounds after applying domain propagation in right branch */ 104 int* nfixedvars, /**< pointer to counter which is increased by the number of deduced variable fixations */ 105 int* naggrvars, /**< pointer to counter which is increased by the number of deduced variable aggregations */ 106 int* nimplications, /**< pointer to counter which is increased by the number of deduced implications */ 107 int* nchgbds, /**< pointer to counter which is increased by the number of deduced bound tightenings */ 108 SCIP_Bool* cutoff /**< buffer to store whether a cutoff is detected */ 109 ); 110 111 /** @} */ 112 113 #ifdef __cplusplus 114 } 115 #endif 116 117 #endif 118