Scippy

SCIP

Solving Constraint Integer Programs

heur_proximity.h
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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"); */
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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
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
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
84  SCIP* scip /** SCIP data structure */
85  );
86 
87 /** @} */
88 
89 #ifdef __cplusplus
90 }
91 #endif
92 
93 #endif
enum SCIP_Result SCIP_RESULT
Definition: type_result.h:61
SCIP_RETCODE SCIPincludeHeurProximity(SCIP *scip)
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
type definitions for return codes for SCIP methods
SCIP_RETCODE SCIPdeleteSubproblemProximity(SCIP *scip)
type definitions for primal heuristics
type definitions for SCIP&#39;s main datastructure
#define SCIP_Bool
Definition: def.h:93
#define SCIP_Real
Definition: def.h:186
result codes for SCIP callback methods
#define SCIP_Longint
Definition: def.h:171
#define nnodes
Definition: gastrans.c:74
common defines and data types used in all packages of SCIP
SCIP_RETCODE SCIPapplyProximity(SCIP *scip, SCIP_HEUR *heur, SCIP_RESULT *result, SCIP_Real minimprove, SCIP_Longint nnodes, SCIP_Longint nlpiters, SCIP_Longint *nusednodes, SCIP_Longint *nusedlpiters, SCIP_Bool freesubscip)