Scippy

SCIP

Solving Constraint Integer Programs

sepa_aggregation.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 sepa_aggregation.h
26  * @ingroup SEPARATORS
27  * @brief flow cover and complemented mixed integer rounding cuts separator (Marchand's version)
28  * @author Leona Gottwald
29  * @author Kati Wolter
30  * @author Tobias Achterberg
31  *
32  * For an overview see:
33  *
34  * Marchand, H., & Wolsey, L. A. (2001).@n
35  * Aggregation and mixed integer rounding to solve MIPs.@n
36  * Operations research, 49(3), 363-371.
37  *
38  * Some remarks:
39  * - In general, continuous variables are less prefered than integer variables, since their cut
40  * coefficient is worse.
41  * - We seek for aggregations that project out continuous variables that are far away from their bound,
42  * since if it is at its bound then it doesn't contribute to the violation
43  * - These aggregations are also useful for the flowcover separation, so after building an aggregation
44  * we try to generate a MIR cut and a flowcover cut.
45  * - We only keep the best cut.
46  */
47 
48 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
49 
50 #ifndef __SCIP_SEPA_CMIR_H__
51 #define __SCIP_SEPA_CMIR_H__
52 
53 
54 #include "scip/def.h"
55 #include "scip/type_retcode.h"
56 #include "scip/type_scip.h"
57 
58 #ifdef __cplusplus
59 extern "C" {
60 #endif
61 
62 /** creates the aggregation separator and includes it in SCIP
63  *
64  * @ingroup SeparatorIncludes
65  */
66 SCIP_EXPORT
68  SCIP* scip /**< SCIP data structure */
69  );
70 
71 #ifdef __cplusplus
72 }
73 #endif
74 
75 #endif
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
SCIP_RETCODE SCIPincludeSepaAggregation(SCIP *scip)
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