# SCIP

Solving Constraint Integer Programs

heur_rounding.h
Go to the documentation of this file.
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_rounding.h
17  * @ingroup PRIMALHEURISTICS
18  * @brief LP rounding heuristic that tries to recover from intermediate infeasibilities
19  * @author Tobias Achterberg
20  *
21  * Rounding heuristic that starts from an LP-feasible point and reduces the number of fractional variables by one in
22  * each step. As long as no LP row is violated, the algorithm iterates over the fractional variables and applies a
23  * rounding into the direction of fewer locks, updating the activities of the LP rows after each step. If there is a
24  * violated LP row, the heuristic will try to find a fractional variable that can be rounded in a direction such that
25  * the violation of the constraint is decreased, using the number of up- and down-locks as a tie breaker. If no
26  * rounding can decrease the violation of the constraint, the procedure is aborted.
27  */
28
29 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
30
31 #ifndef __SCIP_HEUR_ROUNDING_H__
32 #define __SCIP_HEUR_ROUNDING_H__
33
34 #include "scip/def.h"
35 #include "scip/type_retcode.h"
36 #include "scip/type_scip.h"
37
38 #ifdef __cplusplus
39 extern "C" {
40 #endif
41
42 /** creates the rounding heuristic with infeasibility recovering and includes it in SCIP
43  *
44  * @ingroup PrimalHeuristicIncludes
45  */
48  SCIP* scip /**< SCIP data structure */
49  );
50
51 #ifdef __cplusplus
52 }
53 #endif
54
55 #endif
#define SCIP_EXPORT
Definition: def.h:100
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:54
type definitions for return codes for SCIP methods
type definitions for SCIP&#39;s main datastructure
common defines and data types used in all packages of SCIP
SCIP_EXPORT SCIP_RETCODE SCIPincludeHeurRounding(SCIP *scip)