Scippy

SCIP

Solving Constraint Integer Programs

branch_relpscost.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 /* */
6 /* Copyright (c) 2002-2024 Zuse Institute Berlin (ZIB) */
7 /* */
8 /* Licensed under the Apache License, Version 2.0 (the "License"); */
9 /* you may not use this file except in compliance with the License. */
10 /* You may obtain a copy of the License at */
11 /* */
12 /* http://www.apache.org/licenses/LICENSE-2.0 */
13 /* */
14 /* Unless required by applicable law or agreed to in writing, software */
15 /* distributed under the License is distributed on an "AS IS" BASIS, */
16 /* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. */
17 /* See the License for the specific language governing permissions and */
18 /* limitations under the License. */
19 /* */
20 /* You should have received a copy of the Apache-2.0 license */
21 /* along with SCIP; see the file LICENSE. If not visit scipopt.org. */
22 /* */
23 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
24 
25 /**@file branch_relpscost.h
26  * @ingroup BRANCHINGRULES
27  * @brief reliable pseudo costs branching rule
28  * @author Tobias Achterberg
29  *
30  * The reliable pseudo costs branching rule uses the notion of pseudo costs to measure the expected
31  * gain in the dual bound when branching on a particular variable.
32  * The pseudo cost information is collected during the branch-and-bound search in the same manner as for
33  * the pseudo costs branching rule.
34  *
35  * The reliable pseudo costs branching rule, however, uses a limited number of look-ahead LP-iterations
36  * at the beginning of the search in order to obtain better pseudo cost estimates and make branching decisions in a
37  * sense more "reliable" at an early stage of the search,
38  * at the price of a higher computational cost at the beginning of the search.
39  *
40  * For a more mathematical description and a comparison between the reliable pseudo costs rule and other branching rules
41  * in SCIP, we refer to
42  *
43  * @par
44  * Tobias Achterberg@n
45  * Constraint Integer Programming@n
46  * PhD Thesis, Technische Universit├Ąt Berlin, 2007@n
47  */
48 
49 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
50 
51 #ifndef __SCIP_BRANCH_RELPSCOST_H__
52 #define __SCIP_BRANCH_RELPSCOST_H__
53 
54 
55 #include "scip/def.h"
56 #include "scip/type_result.h"
57 #include "scip/type_retcode.h"
58 #include "scip/type_scip.h"
59 #include "scip/type_var.h"
60 
61 #ifdef __cplusplus
62 extern "C" {
63 #endif
64 
65 /** creates the reliable pseudo cost branching rule and includes it in SCIP
66  *
67  * @ingroup BranchingRuleIncludes
68  */
69 SCIP_EXPORT
71  SCIP* scip /**< SCIP data structure */
72  );
73 
74 /**@addtogroup BRANCHINGRULES
75  *
76  * @{
77  */
78 
79 /** execution reliability pseudo cost branching with the given branching candidates */
80 SCIP_EXPORT
82  SCIP* scip, /**< SCIP data structure */
83  SCIP_VAR** branchcands, /**< branching candidates */
84  SCIP_Real* branchcandssol, /**< solution value for the branching candidates */
85  SCIP_Real* branchcandsfrac, /**< fractional part of the branching candidates */
86  int nbranchcands, /**< number of branching candidates */
87  SCIP_Bool executebranching, /**< perform a branching step after probing */
88  SCIP_RESULT* result /**< pointer to the result of the execution */
89  );
90 
91 /** @} */
92 
93 #ifdef __cplusplus
94 }
95 #endif
96 
97 #endif
enum SCIP_Result SCIP_RESULT
Definition: type_result.h:61
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:91
SCIP_RETCODE SCIPincludeBranchruleRelpscost(SCIP *scip)
SCIP_RETCODE SCIPexecRelpscostBranching(SCIP *scip, SCIP_VAR **branchcands, SCIP_Real *branchcandssol, SCIP_Real *branchcandsfrac, int nbranchcands, SCIP_Bool executebranching, SCIP_RESULT *result)
#define SCIP_Real
Definition: def.h:173
result codes for SCIP callback methods
common defines and data types used in all packages of SCIP