Scippy

SCIP

Solving Constraint Integer Programs

branch_pscost.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) 2002-2020 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 visit scipopt.org. */
13 /* */
14 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
15 
16 /**@file branch_pscost.h
17  * @ingroup BRANCHINGRULES
18  * @brief pseudo costs branching rule
19  * @author Tobias Achterberg
20  *
21  * The pseudo costs branching rule selects the branching variable with respect to the so-called pseudo costs
22  * of the variables. Pseudo costs measure the average gain per unit in the objective function when the variable
23  * was branched on upwards or downwards, resp. The required information is updated at every node of
24  * the solving process.
25  *
26  * The selected variable maximizes the expected gain of the dual bound in the created subtree.
27  *
28  * For a more mathematical description and a comparison between the pseudo costs branching rule
29  * and other branching rules in SCIP, we refer to
30  *
31  * @par
32  * Tobias Achterberg@n
33  * Constraint Integer Programming@n
34  * PhD Thesis, Technische Universit├Ąt Berlin, 2007@n
35  */
36 
37 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
38 
39 #ifndef __SCIP_BRANCH_PSCOST_H__
40 #define __SCIP_BRANCH_PSCOST_H__
41 
42 
43 #include "scip/def.h"
44 #include "scip/type_retcode.h"
45 #include "scip/type_scip.h"
46 #include "scip/type_var.h"
47 
48 #ifdef __cplusplus
49 extern "C" {
50 #endif
51 
52 /** creates the pseudo cost branching rule and includes it in SCIP
53  *
54  * @ingroup BranchingRuleIncludes
55  */
58  SCIP* scip /**< SCIP data structure */
59  );
60 
61 /**@addtogroup BRANCHINGRULES
62  *
63  * @{
64  */
65 
66 /** selects a branching variable, due to pseudo cost, from the given candidate array and returns this variable together
67  * with a branching point */
70  SCIP* scip, /**< SCIP data structure */
71  SCIP_VAR** branchcands, /**< branching candidates */
72  SCIP_Real* branchcandssol, /**< solution value for the branching candidates */
73  SCIP_Real* branchcandsscore, /**< array of candidate scores */
74  int nbranchcands, /**< number of branching candidates */
75  SCIP_VAR** var, /**< pointer to store the variable to branch on, or NULL if none */
76  SCIP_Real* brpoint /**< pointer to store the branching point for the branching variable, will be fractional for a discrete variable */
77  );
78 
79 /** @} */
80 
81 #ifdef __cplusplus
82 }
83 #endif
84 
85 #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
type definitions for problem variables
SCIP_EXPORT SCIP_RETCODE SCIPselectBranchVarPscost(SCIP *scip, SCIP_VAR **branchcands, SCIP_Real *branchcandssol, SCIP_Real *branchcandsscore, int nbranchcands, SCIP_VAR **var, SCIP_Real *brpoint)
#define SCIP_Real
Definition: def.h:163
SCIP_EXPORT SCIP_RETCODE SCIPincludeBranchrulePscost(SCIP *scip)
common defines and data types used in all packages of SCIP