1 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ 2 /* */ 3 /* This file is part of the program and library */ 4 /* SCIP --- Solving Constraint Integer Programs */ 5 /* */ 6 /* Copyright (C) 2002-2021 Konrad-Zuse-Zentrum */ 7 /* fuer Informationstechnik Berlin */ 8 /* */ 9 /* SCIP is distributed under the terms of the ZIB Academic License. */ 10 /* */ 11 /* You should have received a copy of the ZIB Academic License */ 12 /* along with SCIP; see the file COPYING. If not visit scipopt.org. */ 13 /* */ 14 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ 15 16 /**@file prop_probing.h 17 * @ingroup PROPAGATORS 18 * @brief probing propagator 19 * @author Tobias Achterberg 20 */ 21 22 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/ 23 24 #ifndef __SCIP_PROP_PROBING_H__ 25 #define __SCIP_PROP_PROBING_H__ 26 27 #include "scip/def.h" 28 #include "scip/type_lp.h" 29 #include "scip/type_retcode.h" 30 #include "scip/type_scip.h" 31 #include "scip/type_var.h" 32 33 #ifdef __cplusplus 34 extern "C" { 35 #endif 36 37 /** creates the probing propagator and includes it in SCIP 38 * 39 * @ingroup PropagatorIncludes 40 */ 41 SCIP_EXPORT 42 SCIP_RETCODE SCIPincludePropProbing( 43 SCIP* scip /**< SCIP data structure */ 44 ); 45 46 /**@addtogroup PROPAGATORS 47 * 48 * @{ 49 */ 50 51 /** applies and evaluates probing of a single variable in the given direction and bound */ 52 SCIP_EXPORT 53 SCIP_RETCODE SCIPapplyProbingVar( 54 SCIP* scip, /**< SCIP data structure */ 55 SCIP_VAR** vars, /**< problem variables */ 56 int nvars, /**< number of problem variables */ 57 int probingpos, /**< variable number to apply probing on */ 58 SCIP_BOUNDTYPE boundtype, /**< which bound should be changed */ 59 SCIP_Real bound, /**< whioch bound should be set */ 60 int maxproprounds, /**< maximal number of propagation rounds (-1: no limit, 0: parameter settings) */ 61 SCIP_Real* impllbs, /**< array to store lower bounds after applying implications and cliques */ 62 SCIP_Real* implubs, /**< array to store upper bounds after applying implications and cliques */ 63 SCIP_Real* proplbs, /**< array to store lower bounds after full propagation */ 64 SCIP_Real* propubs, /**< array to store upper bounds after full propagation */ 65 SCIP_Bool* cutoff /**< pointer to store whether the probing direction is infeasible */ 66 ); 67 68 /** analyses boundchanges resulting from probing on a variable and performs deduced fixations, aggregations, and domain tightenings 69 * 70 * Given a variable probingvar with domain [l,u] and bound tightening results from reducing the 71 * domain once to [l,leftub] and once to [rightlb,u], the method computes and applies resulting 72 * variable fixations, aggregations, implications, and bound changes. Variable probingvar does not 73 * need to be binary. The whole domain of probingvar need to be covered by the left and right 74 * branches, i.e., we assume leftub >= rightlb for continuous variables or floor(leftub) >= 75 * ceil(rightlb)-1 for discrete variables. Bounds after applying implications and cliques do not 76 * need to be provided, but if they are omitted and probingvar is a binary variable, then already 77 * existing implications may be added. 78 */ 79 SCIP_EXPORT 80 SCIP_RETCODE SCIPanalyzeDeductionsProbing( 81 SCIP* scip, /**< SCIP data structure */ 82 SCIP_VAR* probingvar, /**< the probing variable */ 83 SCIP_Real leftub, /**< upper bound of probing variable in left branch */ 84 SCIP_Real rightlb, /**< lower bound of probing variable in right branch */ 85 int nvars, /**< number of variables which bound changes should be analyzed */ 86 SCIP_VAR** vars, /**< variables which bound changes should be analyzed */ 87 SCIP_Real* leftimpllbs, /**< lower bounds after applying implications and cliques in left branch, or NULL */ 88 SCIP_Real* leftimplubs, /**< upper bounds after applying implications and cliques in left branch, or NULL */ 89 SCIP_Real* leftproplbs, /**< lower bounds after applying domain propagation in left branch */ 90 SCIP_Real* leftpropubs, /**< upper bounds after applying domain propagation in left branch */ 91 SCIP_Real* rightimpllbs, /**< lower bounds after applying implications and cliques in right branch, or NULL */ 92 SCIP_Real* rightimplubs, /**< upper bounds after applying implications and cliques in right branch, or NULL */ 93 SCIP_Real* rightproplbs, /**< lower bounds after applying domain propagation in right branch */ 94 SCIP_Real* rightpropubs, /**< upper bounds after applying domain propagation in right branch */ 95 int* nfixedvars, /**< pointer to counter which is increased by the number of deduced variable fixations */ 96 int* naggrvars, /**< pointer to counter which is increased by the number of deduced variable aggregations */ 97 int* nimplications, /**< pointer to counter which is increased by the number of deduced implications */ 98 int* nchgbds, /**< pointer to counter which is increased by the number of deduced bound tightenings */ 99 SCIP_Bool* cutoff /**< buffer to store whether a cutoff is detected */ 100 ); 101 102 /** @} */ 103 104 #ifdef __cplusplus 105 } 106 #endif 107 108 #endif 109