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SCIP

Solving Constraint Integer Programs

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Detailed Description

random variable branching rule

Author: Tobias Achterberg; Stefan Vigerske

Definition in file branch_random.c.

#include <assert.h>
#include <string.h>
#include "scip/branch_random.h"

Go to the source code of this file.

Macros
#define	BRANCHRULE_NAME "random"

#define	BRANCHRULE_DESC "random variable branching"

#define	BRANCHRULE_PRIORITY -100000

#define	BRANCHRULE_MAXDEPTH -1

#define	BRANCHRULE_MAXBOUNDDIST 1.0

#define	DEFAULT_INITSEED 0

Functions
static void	getRandomVariable (SCIP scip, SCIP_VAR cands, SCIP_Real candssol, int ncands, SCIP_VAR *bestcand, SCIP_Real bestcandsol, unsigned int *seed)

static	SCIP_DECL_BRANCHCOPY (branchCopyRandom)

static	SCIP_DECL_BRANCHFREE (branchFreeRandom)

static	SCIP_DECL_BRANCHINIT (branchInitRandom)

static	SCIP_DECL_BRANCHEXECLP (branchExeclpRandom)

static	SCIP_DECL_BRANCHEXECEXT (branchExecextRandom)

static	SCIP_DECL_BRANCHEXECPS (branchExecpsRandom)

SCIP_RETCODE	SCIPincludeBranchruleRandom (SCIP *scip)

Macro Definition Documentation

#define BRANCHRULE_NAME "random"

Definition at line 30 of file branch_random.c.

Referenced by SCIP_DECL_BRANCHCOPY(), SCIP_DECL_BRANCHEXECEXT(), SCIP_DECL_BRANCHEXECLP(), SCIP_DECL_BRANCHEXECPS(), and SCIPincludeBranchruleRandom().

#define BRANCHRULE_DESC "random variable branching"

Definition at line 31 of file branch_random.c.

Referenced by SCIPincludeBranchruleRandom().

#define BRANCHRULE_PRIORITY -100000

Definition at line 32 of file branch_random.c.

Referenced by SCIPincludeBranchruleRandom().

#define BRANCHRULE_MAXDEPTH -1

Definition at line 33 of file branch_random.c.

Referenced by SCIPincludeBranchruleRandom().

#define BRANCHRULE_MAXBOUNDDIST 1.0

Definition at line 34 of file branch_random.c.

Referenced by SCIPincludeBranchruleRandom().

#define DEFAULT_INITSEED 0

initial random seed

Definition at line 36 of file branch_random.c.

Referenced by SCIPincludeBranchruleRandom().

Function Documentation

static void getRandomVariable	(	SCIP *	scip,
		SCIP_VAR **	cands,
		SCIP_Real *	candssol,
		int	ncands,
		SCIP_VAR **	bestcand,
		SCIP_Real *	bestcandsol,
		unsigned int *	seed
	)

static

selects a random active variable from a given list of variables

Parameters

scip	SCIP data structure
cands	array of branching candidates
candssol	relaxation solution values of branching candidates, or NULL
ncands	number of branching candidates
bestcand	buffer to store pointer to best candidate
bestcandsol	buffer to store solution value of best candidate
seed	seed for random number generator

Definition at line 51 of file branch_random.c.

References NULL, SCIP_VARSTATUS_MULTAGGR, SCIPdebugMessage, SCIPgetRandomInt(), SCIPisEQ(), SCIPvarGetLbLocal(), SCIPvarGetMultaggrNVars(), SCIPvarGetMultaggrVars(), SCIPvarGetProbvar(), SCIPvarGetStatus(), SCIPvarGetUbLocal(), and SCIPvarIsActive().

Referenced by SCIP_DECL_BRANCHEXECEXT().

static SCIP_DECL_BRANCHCOPY ( branchCopyRandom )

static

copy method for branchrule plugins (called when SCIP copies plugins)

Definition at line 120 of file branch_random.c.

References BRANCHRULE_NAME, NULL, SCIP_CALL, SCIP_OKAY, SCIPbranchruleGetName(), and SCIPincludeBranchruleRandom().

static SCIP_DECL_BRANCHFREE ( branchFreeRandom )

static

destructor of branching rule to free user data (called when SCIP is exiting)

Definition at line 134 of file branch_random.c.

References NULL, SCIP_OKAY, SCIPbranchruleGetData(), SCIPbranchruleSetData(), and SCIPfreeMemory.

static SCIP_DECL_BRANCHINIT ( branchInitRandom )

static

initialization method of branching rule (called after problem was transformed)

Definition at line 149 of file branch_random.c.

References NULL, SCIP_OKAY, and SCIPbranchruleGetData().

static SCIP_DECL_BRANCHEXECLP ( branchExeclpRandom )

static

branching execution method for fractional LP solutions

Definition at line 165 of file branch_random.c.

References BRANCHRULE_NAME, NULL, SCIP_BRANCHED, SCIP_CALL, SCIP_OKAY, SCIPbranchruleGetData(), SCIPbranchruleGetName(), SCIPbranchVar(), SCIPdebugMessage, SCIPgetDepth(), SCIPgetLPBranchCands(), SCIPgetRandomInt(), and SCIPvarGetName().

static SCIP_DECL_BRANCHEXECEXT ( branchExecextRandom )

static

branching execution method for external candidates

Definition at line 203 of file branch_random.c.

References BRANCHRULE_NAME, getRandomVariable(), NULL, SCIP_BRANCHED, SCIP_CALL, SCIP_DIDNOTRUN, SCIP_OKAY, SCIP_Real, SCIP_REDUCEDDOM, SCIPbranchruleGetData(), SCIPbranchruleGetName(), SCIPbranchVarVal(), SCIPdebugMessage, SCIPerrorMessage, SCIPgetBranchingPoint(), SCIPgetExternBranchCands(), SCIPisEQ(), SCIPvarGetLbLocal(), SCIPvarGetName(), and SCIPvarGetUbLocal().

static SCIP_DECL_BRANCHEXECPS ( branchExecpsRandom )

static

branching execution method for not completely fixed pseudo solutions

Definition at line 270 of file branch_random.c.

References BRANCHRULE_NAME, NULL, SCIP_BRANCHED, SCIP_CALL, SCIP_OKAY, SCIPbranchruleGetData(), SCIPbranchruleGetName(), SCIPbranchVar(), SCIPdebugMessage, SCIPgetPseudoBranchCands(), SCIPgetRandomInt(), and SCIPvarGetName().

SCIP_RETCODE SCIPincludeBranchruleRandom ( SCIP * scip )

creates the random branching rule and includes it in SCIP

Parameters

scip	SCIP data structure

Definition at line 311 of file branch_random.c.

References BRANCHRULE_DESC, BRANCHRULE_MAXBOUNDDIST, BRANCHRULE_MAXDEPTH, BRANCHRULE_NAME, BRANCHRULE_PRIORITY, DEFAULT_INITSEED, FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIPaddIntParam(), SCIPallocMemory, SCIPincludeBranchruleBasic(), SCIPsetBranchruleCopy(), SCIPsetBranchruleExecExt(), SCIPsetBranchruleExecLp(), SCIPsetBranchruleExecPs(), SCIPsetBranchruleFree(), and SCIPsetBranchruleInit().

Referenced by SCIP_DECL_BRANCHCOPY(), and SCIPincludeDefaultPlugins().