branch_pscost.c File Reference

Detailed Description

pseudo costs branching rule

Author

Tobias Achterberg

Stefan Vigerske

Definition in file branch_pscost.c.

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

Go to the source code of this file.

Macros
#define	BRANCHRULE_NAME   "pscost"
#define	BRANCHRULE_DESC   "branching on pseudo cost values"
#define	BRANCHRULE_PRIORITY   2000
#define	BRANCHRULE_MAXDEPTH   -1
#define	BRANCHRULE_MAXBOUNDDIST   1.0
#define	BRANCHRULE_STRATEGIES   "cdsu"
#define	BRANCHRULE_STRATEGY_DEFAULT   'u'
#define	BRANCHRULE_SCOREMINWEIGHT_DEFAULT   0.8
#define	BRANCHRULE_SCOREMAXWEIGHT_DEFAULT   1.3
#define	BRANCHRULE_SCORESUMWEIGHT_DEFAULT   0.1
#define	BRANCHRULE_NCHILDREN_DEFAULT   2
#define	BRANCHRULE_NARYMAXDEPTH_DEFAULT   -1
#define	BRANCHRULE_NARYMINWIDTH_DEFAULT   0.001
#define	BRANCHRULE_NARYWIDTHFAC_DEFAULT   2.0
#define	WEIGHTEDSCORING(data, min, max, sum)   ((data)->scoreminweight * (min) + (data)->scoremaxweight * (max) + (data)->scoresumweight * (sum))

Functions
static SCIP_RETCODE	updateBestCandidate (SCIP *scip, SCIP_BRANCHRULEDATA *branchruledata, SCIP_VAR **bestvar, SCIP_Real *bestbrpoint, SCIP_Real *bestscore, SCIP_VAR *cand, SCIP_Real candscoremin, SCIP_Real candscoremax, SCIP_Real candscoresum, SCIP_Real candsol)
static SCIP_RETCODE	selectBranchVar (SCIP *scip, SCIP_BRANCHRULE *branchrule, SCIP_VAR **cands, SCIP_Real *candssol, SCIP_Real *candsscore, int ncands, SCIP_VAR **brvar, SCIP_Real *brpoint)
static	SCIP_DECL_BRANCHCOPY (branchCopyPscost)
static	SCIP_DECL_BRANCHFREE (branchFreePscost)
static	SCIP_DECL_BRANCHEXECLP (branchExeclpPscost)
static	SCIP_DECL_BRANCHEXECEXT (branchExecextPscost)
SCIP_RETCODE	SCIPincludeBranchrulePscost (SCIP *scip)
SCIP_RETCODE	SCIPselectBranchVarPscost (SCIP *scip, SCIP_VAR **branchcands, SCIP_Real *branchcandssol, SCIP_Real *branchcandsscore, int nbranchcands, SCIP_VAR **var, SCIP_Real *brpoint)

Macro Definition Documentation

#define BRANCHRULE_NAME   "pscost"

Definition at line 29 of file branch_pscost.c.

Referenced by SCIP_DECL_BRANCHCOPY(), SCIP_DECL_BRANCHEXECEXT(), SCIP_DECL_BRANCHEXECLP(), SCIPincludeBranchrulePscost(), and SCIPselectBranchVarPscost().

#define BRANCHRULE_DESC   "branching on pseudo cost values"

Definition at line 30 of file branch_pscost.c.

Referenced by SCIPincludeBranchrulePscost().

#define BRANCHRULE_PRIORITY   2000

Definition at line 31 of file branch_pscost.c.

Referenced by SCIPincludeBranchrulePscost().

#define BRANCHRULE_MAXDEPTH   -1

Definition at line 32 of file branch_pscost.c.

Referenced by SCIPincludeBranchrulePscost().

#define BRANCHRULE_MAXBOUNDDIST   1.0

Definition at line 33 of file branch_pscost.c.

Referenced by SCIPincludeBranchrulePscost().

#define BRANCHRULE_STRATEGIES   "cdsu"

possible pseudo cost multiplication strategies for branching on external candidates

Definition at line 35 of file branch_pscost.c.

Referenced by SCIPincludeBranchrulePscost().

#define BRANCHRULE_STRATEGY_DEFAULT   'u'

default pseudo cost multiplication strategy

Definition at line 36 of file branch_pscost.c.

Referenced by SCIPincludeBranchrulePscost().

#define BRANCHRULE_SCOREMINWEIGHT_DEFAULT   0.8

default weight for minimum of scores of a branching candidate

Definition at line 37 of file branch_pscost.c.

Referenced by SCIPincludeBranchrulePscost().

#define BRANCHRULE_SCOREMAXWEIGHT_DEFAULT   1.3

default weight for maximum of scores of a branching candidate

Definition at line 38 of file branch_pscost.c.

Referenced by SCIPincludeBranchrulePscost().

#define BRANCHRULE_SCORESUMWEIGHT_DEFAULT   0.1

default weight for sum of scores of a branching candidate

Definition at line 39 of file branch_pscost.c.

Referenced by SCIPincludeBranchrulePscost().

#define BRANCHRULE_NCHILDREN_DEFAULT   2

default number of children in n-ary branching

Definition at line 40 of file branch_pscost.c.

Referenced by SCIPincludeBranchrulePscost().

#define BRANCHRULE_NARYMAXDEPTH_DEFAULT   -1

default maximal depth where to do n-ary branching

Definition at line 41 of file branch_pscost.c.

Referenced by SCIPincludeBranchrulePscost().

#define BRANCHRULE_NARYMINWIDTH_DEFAULT   0.001

default minimal domain width in children when doing n-ary branching

Definition at line 42 of file branch_pscost.c.

Referenced by SCIPincludeBranchrulePscost().

#define BRANCHRULE_NARYWIDTHFAC_DEFAULT   2.0

default factor of domain width in n-ary branching

Definition at line 43 of file branch_pscost.c.

Referenced by SCIPincludeBranchrulePscost().

#define WEIGHTEDSCORING	(		data,
			min,
			max,
			sum
	)		((data)->scoreminweight * (min) + (data)->scoremaxweight * (max) + (data)->scoresumweight * (sum))

Definition at line 45 of file branch_pscost.c.

Referenced by updateBestCandidate().

Function Documentation

static SCIP_RETCODE updateBestCandidate ( SCIP *  scip, SCIP_BRANCHRULEDATA *  branchruledata, SCIP_VAR **  bestvar, SCIP_Real *  bestbrpoint, SCIP_Real *  bestscore, SCIP_VAR *  cand, SCIP_Real  candscoremin, SCIP_Real  candscoremax, SCIP_Real  candscoresum, SCIP_Real  candsol  )

static

checks if a given branching candidate is better than a previous one and updates the best branching candidate accordingly

Parameters

scip	SCIP data structure
branchruledata	branching rule data
bestvar	best branching candidate
bestbrpoint	branching point for best branching candidate
bestscore	score of best branching candidate
cand	branching candidate to consider
candscoremin	minimal score of branching candidate
candscoremax	maximal score of branching candidate
candscoresum	sum of scores of branching candidate
candsol	proposed branching point of branching candidate

Definition at line 70 of file branch_pscost.c.

References FALSE, NULL, REALABS, SCIP_Bool, SCIP_CALL, SCIP_INVALID, SCIP_INVALIDDATA, SCIP_OKAY, SCIP_Real, SCIP_VARSTATUS_MULTAGGR, SCIP_VARTYPE_CONTINUOUS, SCIPABORT, SCIPadjustedVarLb(), SCIPadjustedVarUb(), SCIPcomputeVarLbLocal(), SCIPcomputeVarUbLocal(), SCIPdebugMessage, SCIPerrorMessage, SCIPgetBranchingPoint(), SCIPgetBranchScore(), SCIPgetSolVal(), SCIPgetVarPseudocostVal(), SCIPinfinity(), SCIPisEQ(), SCIPisFeasGE(), SCIPisFeasLE(), SCIPisHugeValue(), SCIPisInfinity(), SCIPisIntegral(), SCIPisNegative(), SCIPisSumEQ(), SCIPisSumGT(), SCIPvarGetLbLocal(), SCIPvarGetMultaggrNVars(), SCIPvarGetMultaggrScalars(), SCIPvarGetMultaggrVars(), SCIPvarGetName(), SCIPvarGetProbvar(), SCIPvarGetStatus(), SCIPvarGetType(), SCIPvarGetUbLocal(), SCIPvarIsActive(), TRUE, and WEIGHTEDSCORING.

Referenced by selectBranchVar().

static SCIP_RETCODE selectBranchVar ( SCIP *  scip, SCIP_BRANCHRULE *  branchrule, SCIP_VAR **  cands, SCIP_Real *  candssol, SCIP_Real *  candsscore, int  ncands, SCIP_VAR **  brvar, SCIP_Real *  brpoint  )

static

selects the branching variable from given candidate array

Parameters

scip	SCIP data structure
branchrule	branching rule
cands	array of branching candidates
candssol	array of candidate solution values
candsscore	array of candidate scores
ncands	the number of candidates
brvar	pointer to store the selected branching candidate or NULL if none
brpoint	pointer to store branching point of selected branching variable

Definition at line 356 of file branch_pscost.c.

References NULL, REALABS, SCIP_BRANCHERROR, SCIP_CALL, SCIP_INVALID, SCIP_OKAY, SCIP_Real, SCIPABORT, SCIPallocBufferArray, SCIPbranchruleGetData(), SCIPduplicateBufferArray, SCIPerrorMessage, SCIPfreeBufferArray, SCIPisEQ(), SCIPisInfinity(), SCIPsortPtrInt(), SCIPvarCompare(), SCIPvarGetLbLocal(), SCIPvarGetUbLocal(), and updateBestCandidate().

Referenced by SCIP_DECL_BRANCHEXECEXT(), and SCIPselectBranchVarPscost().

static SCIP_DECL_BRANCHCOPY ( branchCopyPscost  )

static

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

Definition at line 464 of file branch_pscost.c.

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

static SCIP_DECL_BRANCHFREE ( branchFreePscost  )

static

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

Definition at line 478 of file branch_pscost.c.

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

static SCIP_DECL_BRANCHEXECLP ( branchExeclpPscost  )

static

branching execution method for fractional LP solutions

Definition at line 493 of file branch_pscost.c.

References BRANCHRULE_NAME, NULL, REALABS, SCIP_BRANCHED, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPbranchruleGetName(), SCIPbranchVar(), SCIPdebugMessage, SCIPgetLPBranchCands(), SCIPgetVarPseudocostScore(), SCIPinfinity(), SCIPisFeasIntegral(), SCIPisSumEQ(), SCIPisSumGT(), SCIPvarGetName(), and SCIPvarGetRootSol().

static SCIP_DECL_BRANCHEXECEXT ( branchExecextPscost  )

static

branching execution method for external candidates

Definition at line 550 of file branch_pscost.c.

References BRANCHRULE_NAME, NULL, SCIP_BRANCHED, SCIP_CALL, SCIP_DIDNOTRUN, SCIP_OKAY, SCIP_Real, SCIP_REDUCEDDOM, SCIPadjustedVarLb(), SCIPadjustedVarUb(), SCIPbranchruleGetData(), SCIPbranchruleGetName(), SCIPbranchVarValNary(), SCIPdebugMessage, SCIPerrorMessage, SCIPgetCharParam(), SCIPgetCurrentNode(), SCIPgetExternBranchCands(), SCIPisEQ(), SCIPisInfinity(), SCIPnodeGetDepth(), SCIPvarGetLbGlobal(), SCIPvarGetLbLocal(), SCIPvarGetName(), SCIPvarGetProbvar(), SCIPvarGetUbGlobal(), SCIPvarGetUbLocal(), SCIPvarIsActive(), and selectBranchVar().

SCIP_RETCODE SCIPincludeBranchrulePscost

(

SCIP *

scip

)

creates the pseudo cost branching rule and includes it in SCIP

Parameters

scip	SCIP data structure

Definition at line 633 of file branch_pscost.c.

References BRANCHRULE_DESC, BRANCHRULE_MAXBOUNDDIST, BRANCHRULE_MAXDEPTH, BRANCHRULE_NAME, BRANCHRULE_NARYMAXDEPTH_DEFAULT, BRANCHRULE_NARYMINWIDTH_DEFAULT, BRANCHRULE_NARYWIDTHFAC_DEFAULT, BRANCHRULE_NCHILDREN_DEFAULT, BRANCHRULE_PRIORITY, BRANCHRULE_SCOREMAXWEIGHT_DEFAULT, BRANCHRULE_SCOREMINWEIGHT_DEFAULT, BRANCHRULE_SCORESUMWEIGHT_DEFAULT, BRANCHRULE_STRATEGIES, BRANCHRULE_STRATEGY_DEFAULT, FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIP_REAL_MAX, SCIPaddCharParam(), SCIPaddIntParam(), SCIPaddRealParam(), SCIPallocMemory, SCIPincludeBranchruleBasic(), SCIPinfinity(), SCIPsetBranchruleCopy(), SCIPsetBranchruleExecExt(), SCIPsetBranchruleExecLp(), SCIPsetBranchruleFree(), and TRUE.

Referenced by SCIP_DECL_BRANCHCOPY(), and SCIPincludeDefaultPlugins().

SCIP_RETCODE SCIPselectBranchVarPscost	(	SCIP *	scip,
		SCIP_VAR **	branchcands,
		SCIP_Real *	branchcandssol,
		SCIP_Real *	branchcandsscore,
		int	nbranchcands,
		SCIP_VAR **	var,
		SCIP_Real *	brpoint
	)

selects a branching variable, due to pseudo cost, from the given candidate array and returns this variable together with a branching point

Parameters

scip	SCIP data structure
branchcands	branching candidates
branchcandssol	solution value for the branching candidates
branchcandsscore	array of candidate scores
nbranchcands	number of branching candidates
var	pointer to store the variable to branch on, or NULL if none
brpoint	pointer to store the branching point for the branching variable, will be fractional for a discrete variable

Definition at line 692 of file branch_pscost.c.

References BRANCHRULE_NAME, NULL, SCIP_CALL, SCIP_OKAY, SCIPfindBranchrule(), and selectBranchVar().