Scippy

SCIP

Solving Constraint Integer Programs

scip_randnumgen.c
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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) 2002-2024 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 scip_randnumgen.c
26 * @ingroup OTHER_CFILES
27 * @brief public methods for random numbers
28 * @author Tobias Achterberg
29 * @author Timo Berthold
30 * @author Gerald Gamrath
31 * @author Leona Gottwald
32 * @author Stefan Heinz
33 * @author Gregor Hendel
34 * @author Thorsten Koch
35 * @author Alexander Martin
36 * @author Marc Pfetsch
37 * @author Michael Winkler
38 * @author Kati Wolter
39 *
40 * @todo check all SCIP_STAGE_* switches, and include the new stages TRANSFORMED and INITSOLVE
41 */
42
43/*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
44
45#include "scip/misc.h"
46#include "scip/pub_message.h"
47#include "scip/scip_mem.h"
49#include "scip/set.h"
50#include "scip/struct_scip.h"
51
52/** creates and initializes a random number generator
53 *
54 * @note The initial seed is changed using SCIPinitializeRandomSeed()
55 */
57 SCIP* scip, /**< SCIP data structure */
58 SCIP_RANDNUMGEN** randnumgen, /**< random number generator */
59 unsigned int initialseed, /**< initial random seed */
60 SCIP_Bool useglobalseed /**< should the supplied seed be initialized by SCIP's global seed shift? */
61 )
62{
63 unsigned int modifiedseed;
64
65 assert(scip != NULL);
66 assert(randnumgen != NULL);
67
68 if( useglobalseed )
69 modifiedseed = SCIPinitializeRandomSeed(scip, initialseed);
70 else
71 modifiedseed = initialseed;
72
73 SCIP_CALL( SCIPrandomCreate(randnumgen, SCIPblkmem(scip), modifiedseed) );
74
75 return SCIP_OKAY;
76}
77
78/** frees a random number generator */
80 SCIP* scip, /**< SCIP data structure */
81 SCIP_RANDNUMGEN** randnumgen /**< random number generator */
82 )
83{
84 assert(scip != NULL);
85 assert(randnumgen != NULL);
86
87 SCIPrandomFree(randnumgen, SCIPblkmem(scip));
88}
89
90/** initializes a random number generator with a given start seed
91 *
92 * @note The seed is changed using SCIPinitializeRandomSeed()
93 */
95 SCIP* scip, /**< SCIP data structure */
96 SCIP_RANDNUMGEN* randnumgen, /**< random number generator */
97 unsigned int seed /**< new random seed */
98 )
99{
100 unsigned int modifiedseed;
101
102 assert(scip != NULL);
103 assert(randnumgen != NULL);
104
105 modifiedseed = SCIPinitializeRandomSeed(scip, seed);
106
107 SCIPrandomSetSeed(randnumgen, modifiedseed);
108}
109
110/** modifies an initial seed value with the global shift of random seeds */
112 SCIP* scip, /**< SCIP data structure */
113 unsigned int initialseedvalue /**< initial seed value to be modified */
114 )
115{
116 assert(scip != NULL);
117
118 return SCIPsetInitializeRandomSeed(scip->set, initialseedvalue);
119}
#define NULL
Definition: def.h:267
#define SCIP_Bool
Definition: def.h:91
#define SCIP_CALL(x)
Definition: def.h:374
void SCIPfreeRandom(SCIP *scip, SCIP_RANDNUMGEN **randnumgen)
void SCIPsetRandomSeed(SCIP *scip, SCIP_RANDNUMGEN *randnumgen, unsigned int seed)
unsigned int SCIPinitializeRandomSeed(SCIP *scip, unsigned int initialseedvalue)
SCIP_RETCODE SCIPcreateRandom(SCIP *scip, SCIP_RANDNUMGEN **randnumgen, unsigned int initialseed, SCIP_Bool useglobalseed)
void SCIPrandomFree(SCIP_RANDNUMGEN **randnumgen, BMS_BLKMEM *blkmem)
Definition: misc.c:10092
SCIP_RETCODE SCIPrandomCreate(SCIP_RANDNUMGEN **randnumgen, BMS_BLKMEM *blkmem, unsigned int initialseed)
Definition: misc.c:10076
void SCIPrandomSetSeed(SCIP_RANDNUMGEN *randnumgen, unsigned int initseed)
Definition: misc.c:10022
internal miscellaneous methods
BMS_BLKMEM * SCIPblkmem(SCIP *scip)
Definition: scip_mem.c:57
public methods for message output
public methods for memory management
public methods for random numbers
unsigned int SCIPsetInitializeRandomSeed(SCIP_SET *set, unsigned int initialseedvalue)
Definition: set.c:7393
internal methods for global SCIP settings
SCIP main data structure.
@ SCIP_OKAY
Definition: type_retcode.h:42
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63