# SCIP

Solving Constraint Integer Programs

heur_rens.h
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1 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
2 /* */
3 /* This file is part of the program and library */
4 /* SCIP --- Solving Constraint Integer Programs */
5 /* */
7 /* fuer Informationstechnik Berlin */
8 /* */
10 /* */
12 /* along with SCIP; see the file COPYING. If not visit scipopt.org. */
13 /* */
14 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
15
16 /**@file heur_rens.h
17  * @ingroup PRIMALHEURISTICS
18  * @brief LNS heuristic that finds the optimal rounding to a given point
19  * @author Timo Berthold
20  *
21  * RENS is a large neighborhood search start heuristic, i.e., unlike other LNS heuristics, it does not need a known
22  * feasible solution. It solves a sub-SCIP that is created by fixing variables which take an integral value in a given
23  * LP or NLP solution. For the remaining integer variables, the bounds get tightened to the two nearest integral values.
24  */
25
26 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
27
28 #ifndef __SCIP_HEUR_RENS_H__
29 #define __SCIP_HEUR_RENS_H__
30
31 #include "scip/def.h"
32 #include "scip/type_heur.h"
33 #include "scip/type_result.h"
34 #include "scip/type_retcode.h"
35 #include "scip/type_scip.h"
36
37 #ifdef __cplusplus
38 extern "C" {
39 #endif
40
41 /** creates RENS primal heuristic and includes it in SCIP
42  *
43  * @ingroup PrimalHeuristicIncludes
44  */
45 SCIP_EXPORT
47  SCIP* scip /**< SCIP data structure */
48  );
49
51  *
52  * @{
53  */
54
55 /** main procedure of the RNS heuristic, creates and solves a sub-SCIP */
56 SCIP_EXPORT
58  SCIP* scip, /**< original SCIP data structure */
59  SCIP_HEUR* heur, /**< heuristic data structure */
60  SCIP_RESULT* result, /**< result data structure */
61  SCIP_Real minfixingrate, /**< minimum percentage of integer variables that have to be fixed */
62  SCIP_Real minimprove, /**< factor by which RENS should at least improve the incumbent */
63  SCIP_Longint maxnodes, /**< maximum number of nodes for the subproblem */
64  SCIP_Longint nstallnodes, /**< number of stalling nodes for the subproblem */
65  char startsol, /**< solution used for fixing values ('l'p relaxation, 'n'lp relaxation) */
66  SCIP_Bool binarybounds, /**< should general integers get binary bounds [floor(.),ceil(.)]? */
67  SCIP_Bool uselprows /**< should subproblem be created out of the rows in the LP rows? */
68  );
69
70 /** @} */
71
72 #ifdef __cplusplus
73 }
74 #endif
75
76 #endif
enum SCIP_Result SCIP_RESULT
Definition: type_result.h:52
SCIP_RETCODE SCIPapplyRens(SCIP *scip, SCIP_HEUR *heur, SCIP_RESULT *result, SCIP_Real minfixingrate, SCIP_Real minimprove, SCIP_Longint maxnodes, SCIP_Longint nstallnodes, char startsol, SCIP_Bool binarybounds, SCIP_Bool uselprows)
Definition: heur_rens.c:594
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:54
type definitions for return codes for SCIP methods
SCIP_RETCODE SCIPincludeHeurRens(SCIP *scip)
Definition: heur_rens.c:810
type definitions for primal heuristics
type definitions for SCIP&#39;s main datastructure
#define SCIP_Bool
Definition: def.h:84
#define SCIP_Real
Definition: def.h:177
result codes for SCIP callback methods
#define SCIP_Longint
Definition: def.h:162
common defines and data types used in all packages of SCIP