Scippy

SCIP

Solving Constraint Integer Programs

branch_fullstrong.h
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2 /* */
3 /* This file is part of the program and library */
4 /* SCIP --- Solving Constraint Integer Programs */
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24 
25 /**@file branch_fullstrong.h
26  * @ingroup BRANCHINGRULES
27  * @brief full strong LP branching rule
28  * @author Tobias Achterberg
29  *
30  * The full strong branching rule applies strong branching to every fractional variable of the LP solution
31  * at the current node of the branch-and-bound search. The rule selects the candidate
32  * which will cause the highest gain of the dual bound in the created sub-tree among all branching variables.
33  *
34  * For calculating the gain, a look-ahead is performed by solving the child node LPs which will result
35  * from branching on a variable.
36  *
37  * For a more mathematical description and a comparison between the strong branching rule and other branching rules
38  * in SCIP, we refer to
39  *
40  * @par
41  * Tobias Achterberg@n
42  * Constraint Integer Programming@n
43  * PhD Thesis, Technische Universit├Ąt Berlin, 2007@n
44  *
45  *
46  */
47 
48 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
49 
50 #ifndef __SCIP_BRANCH_FULLSTRONG_H__
51 #define __SCIP_BRANCH_FULLSTRONG_H__
52 
53 
54 #include "scip/def.h"
55 #include "scip/type_result.h"
56 #include "scip/type_retcode.h"
57 #include "scip/type_scip.h"
58 #include "scip/type_var.h"
59 
60 #ifdef __cplusplus
61 extern "C" {
62 #endif
63 
64 /** creates the full strong LP branching rule and includes it in SCIP
65  *
66  * @ingroup BranchingRuleIncludes
67  */
68 SCIP_EXPORT
70  SCIP* scip /**< SCIP data structure */
71  );
72 
73 /**@addtogroup BRANCHINGRULES
74  *
75  * @{
76  */
77 
78 /**
79  * Selects a variable from a set of candidates by strong branching
80  *
81  * @return \ref SCIP_OKAY is returned if everything worked. Otherwise a suitable error code is passed. See \ref
82  * SCIP_Retcode "SCIP_RETCODE" for a complete list of error codes.
83  *
84  * @note The variables in the lpcands array must have a fractional value in the current LP solution
85  */
86 SCIP_EXPORT
88  SCIP* scip, /**< original SCIP data structure */
89  SCIP_VAR** lpcands, /**< branching candidates */
90  SCIP_Real* lpcandssol, /**< solution values of the branching candidates */
91  SCIP_Real* lpcandsfrac, /**< fractional values of the branching candidates */
92  SCIP_Bool* skipdown, /**< should down branchings be skipped? */
93  SCIP_Bool* skipup, /**< should up branchings be skipped? */
94  int nlpcands, /**< number of branching candidates */
95  int npriolpcands, /**< number of priority branching candidates */
96  int ncomplete, /**< number of branching candidates without skip */
97  int* start, /**< starting index in lpcands */
98  int maxproprounds, /**< maximum number of propagation rounds to be performed during strong
99  * branching before solving the LP (-1: no limit, -2: parameter settings) */
100  SCIP_Bool probingbounds, /**< should valid bounds be identified in a probing-like fashion during
101  * strong branching (only with propagation)? */
102  SCIP_Bool forcestrongbranch, /**< should strong branching be applied even if there is just a single candidate? */
103  int* bestcand, /**< best candidate for branching */
104  SCIP_Real* bestdown, /**< objective value of the down branch for bestcand */
105  SCIP_Real* bestup, /**< objective value of the up branch for bestcand */
106  SCIP_Real* bestscore, /**< score for bestcand */
107  SCIP_Bool* bestdownvalid, /**< is bestdown a valid dual bound for the down branch? */
108  SCIP_Bool* bestupvalid, /**< is bestup a valid dual bound for the up branch? */
109  SCIP_Real* provedbound, /**< proved dual bound for current subtree */
110  SCIP_RESULT* result /**< result pointer */
111  );
112 
113 /** @} */
114 
115 #ifdef __cplusplus
116 }
117 #endif
118 
119 #endif
enum SCIP_Result SCIP_RESULT
Definition: type_result.h:61
SCIP_RETCODE SCIPselectVarStrongBranching(SCIP *scip, SCIP_VAR **lpcands, SCIP_Real *lpcandssol, SCIP_Real *lpcandsfrac, SCIP_Bool *skipdown, SCIP_Bool *skipup, int nlpcands, int npriolpcands, int ncomplete, int *start, int maxproprounds, SCIP_Bool probingbounds, SCIP_Bool forcestrongbranch, int *bestcand, SCIP_Real *bestdown, SCIP_Real *bestup, SCIP_Real *bestscore, SCIP_Bool *bestdownvalid, SCIP_Bool *bestupvalid, SCIP_Real *provedbound, SCIP_RESULT *result)
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
type definitions for return codes for SCIP methods
type definitions for SCIP&#39;s main datastructure
type definitions for problem variables
#define SCIP_Bool
Definition: def.h:93
SCIP_RETCODE SCIPincludeBranchruleFullstrong(SCIP *scip)
#define SCIP_Real
Definition: def.h:186
result codes for SCIP callback methods
common defines and data types used in all packages of SCIP