Scippy

SCIP

Solving Constraint Integer Programs

heur_dualval.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) 2002-2017 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 email to scip@zib.de. */
13 /* */
14 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
15 
16 /**@file heur_dualval.h
17  * @ingroup PRIMALHEURISTICS
18  * @brief primal heuristic that uses dualvalues for successive switching variable values
19  * @author Tobias Buchwald
20  *
21  * This heuristic tries to find solutions by taking the LP or NLP, rounding solution values, fixing the variables to the
22  * rounded values and then changing some of the values.To determine which variable is changed we give each variable a
23  * ranking dependent on its dualvalue. We work with a transformed problem that is always feasible and has objective = 0
24  * iff the original problem is also feasible. Thus we cannot expect to find really good solutions.
25  */
26 
27 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
28 
29 #ifndef __SCIP_HEUR_DUALVAL_H__
30 #define __SCIP_HEUR_DUALVAL_H__
31 
32 
33 #include "scip/scip.h"
34 
35 #ifdef __cplusplus
36 extern "C" {
37 #endif
38 
39 /** creates the dualVal primal heuristic and includes it in SCIP
40  *
41  * @ingroup PrimalHeuristicIncludes
42  */
43 extern
45  SCIP* scip /**< SCIP data structure */
46  );
47 
48 /**@addtogroup PRIMALHEURISTICS
49  *
50  * @{
51  */
52 
53 /** main procedure of the dualval heuristic */
54 extern
56  SCIP* scip, /**< original SCIP data structure */
57  SCIP_HEUR* heur, /**< heuristic data structure */
58  SCIP_RESULT* result, /**< pointer to store result of: did not run, solution found, no solution
59  * found, or fixing is infeasible (cutoff) */
60  SCIP_SOL* refpoint /**< point to take fixation of discrete variables from; if NULL, then LP
61  * solution is used */
62  );
63 
64 /* @} */
65 
66 #ifdef __cplusplus
67 }
68 #endif
69 
70 #endif
enum SCIP_Result SCIP_RESULT
Definition: type_result.h:52
SCIP_RETCODE SCIPapplyHeurDualval(SCIP *scip, SCIP_HEUR *heur, SCIP_RESULT *result, SCIP_SOL *refpoint)
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:53
SCIP_RETCODE SCIPincludeHeurDualval(SCIP *scip)
SCIP callable library.