branch_lookahead.c File Reference

Detailed Description

lookahead LP branching rule

Author

Christoph Schubert

Gerald Gamrath

The (multi-level) lookahead branching rule applies strong branching to every fractional value of the LP solution at the current node of the branch-and-bound tree, as well as recursivly to every temporary child problem created by this strong branching. The rule selects the candidate with the best proven dual bound.

The branching rule was motivated by the following technical report:

Wasu Glankwamdee and Jeff Linderoth
Lookahead Branching for Mixed Integer Programming
Technical Report 06T-004, Department of Industrial and Systems Engineering, Lehigh University.

For a more mathematical description and a comparison between lookahead branching and other branching rules in SCIP, we refer to

Christoph Schubert
Multi-Level Lookahead Branching
Master Thesis, Technische Universität Berlin, 2017

Definition in file branch_lookahead.c.

#include "blockmemshell/memory.h"
#include "lpi/lpi.h"
#include "scip/branch_lookahead.h"
#include "scip/cons_logicor.h"
#include "scip/pub_branch.h"
#include "scip/pub_message.h"
#include "scip/pub_misc.h"
#include "scip/pub_tree.h"
#include "scip/pub_var.h"
#include "scip/scip_branch.h"
#include "scip/scip_cons.h"
#include "scip/scip_exact.h"
#include "scip/scip_general.h"
#include "scip/scip_lp.h"
#include "scip/scip_mem.h"
#include "scip/scip_message.h"
#include "scip/scip_numerics.h"
#include "scip/scip_param.h"
#include "scip/scip_prob.h"
#include "scip/scip_probing.h"
#include "scip/scip_sol.h"
#include "scip/scip_solvingstats.h"
#include "scip/scip_tree.h"
#include "scip/scip_var.h"
#include <string.h>

Go to the source code of this file.

Data Structures
struct	WARMSTARTINFO
struct	CANDIDATE
struct	BRANCHINGDECISION
struct	BRANCHINGRESULTDATA
struct	LEVEL2RESULT
struct	LEVEL2DATA
struct	PERSISTENTDATA
struct	CONFIGURATION
struct	CONSTRAINTLIST
struct	BINARYVARLIST
struct	BINCONSDATA
struct	CANDIDATELIST
struct	DOMAINREDUCTIONS
struct	STATUS
struct	SCORECONTAINER

Macros
#define	BRANCHRULE_NAME   "lookahead"
#define	BRANCHRULE_DESC   "full strong branching over multiple levels"
#define	BRANCHRULE_PRIORITY   0
#define	BRANCHRULE_MAXDEPTH   -1
#define	BRANCHRULE_MAXBOUNDDIST   1.0
#define	DEFAULT_USEBINARYCONSTRAINTS   FALSE
#define	DEFAULT_ADDCLIQUE   FALSE
#define	DEFAULT_ADDBINCONSROW   0
#define	DEFAULT_USEDOMAINREDUCTION   TRUE
#define	DEFAULT_MERGEDOMAINREDUCTIONS   FALSE
#define	DEFAULT_PREFERSIMPLEBOUNDS   FALSE
#define	DEFAULT_ONLYVIOLDOMREDS   FALSE
#define	DEFAULT_MAXNVIOLATEDCONS   1
#define	DEFAULT_MAXNVIOLATEDBINCONS   0
#define	DEFAULT_MAXNVIOLATEDDOMREDS   1
#define	DEFAULT_STOREUNVIOLATEDSOL   TRUE
#define	DEFAULT_REEVALAGE   10LL
#define	DEFAULT_REEVALAGEFSB   10LL
#define	DEFAULT_RECURSIONDEPTH   2
#define	DEFAULT_ADDNONVIOCONS   FALSE
#define	DEFAULT_PROPAGATE   TRUE
#define	DEFAULT_USELEVEL2DATA   TRUE
#define	DEFAULT_APPLYCHILDBOUNDS   FALSE
#define	DEFAULT_ENFORCEMAXDOMREDS   FALSE
#define	DEFAULT_UPDATEBRANCHINGRESULTS   FALSE
#define	DEFAULT_MAXPROPROUNDS   0
#define	DEFAULT_ABBREVIATED   TRUE
#define	DEFAULT_MAXNCANDS   4
#define	DEFAULT_MAXNDEEPERCANDS   2
#define	DEFAULT_REUSEBASIS   TRUE
#define	DEFAULT_ABBREVPSEUDO   FALSE
#define	DEFAULT_LEVEL2AVGSCORE   FALSE
#define	DEFAULT_LEVEL2ZEROSCORE   FALSE
#define	DEFAULT_SCORINGFUNCTION   'a'
#define	DEFAULT_DEEPERSCORINGFUNCTION   'x'
#define	DEFAULT_SCORINGSCORINGFUNCTION   'd'
#define	DEFAULT_MINWEIGHT   0.8
#define	DEFAULT_WORSEFACTOR   -1.0
#define	DEFAULT_FILTERBYMAXGAIN   FALSE
#define	LABdebugMessage(scip, lvl, ...)
#define	level2resultPrint(scip, result)

Functions
static SCIP_RETCODE	warmStartInfoCreate (SCIP *scip, WARMSTARTINFO **warmstartinfo)
static SCIP_Bool	warmStartInfoIsAvailable (WARMSTARTINFO *warmstartinfo)
static SCIP_RETCODE	warmStartInfoFree (SCIP *scip, WARMSTARTINFO **warmstartinfo)
static SCIP_RETCODE	candidateCreate (SCIP *scip, CANDIDATE **candidate)
static SCIP_RETCODE	candidateFreeWarmStartInfo (SCIP *scip, CANDIDATE *candidate)
static SCIP_RETCODE	candidateFree (SCIP *scip, CANDIDATE **candidate)
static SCIP_RETCODE	candidateStoreWarmStartInfo (SCIP *scip, CANDIDATE *candidate, SCIP_Bool down)
static SCIP_Bool	candidateHasWarmStartInfo (CANDIDATE *candidate, SCIP_Bool down)
static SCIP_RETCODE	candidateLoadWarmStartInfo (SCIP *scip, CANDIDATE *candidate, SCIP_Bool down)
static void	branchingDecisionInit (SCIP *scip, BRANCHINGDECISION *decision)
static SCIP_RETCODE	branchingDecisionCreate (SCIP *scip, BRANCHINGDECISION **decision)
static void	branchingDecisionCopy (BRANCHINGDECISION *sourcedecision, BRANCHINGDECISION *targetdecision)
static SCIP_Bool	branchingDecisionIsValid (BRANCHINGDECISION *decision)
static SCIP_RETCODE	branchingDecisionEnsureBoundArraysSize (SCIP *scip, BRANCHINGDECISION *decision, int nvars)
static void	branchingDecisionFree (SCIP *scip, BRANCHINGDECISION **decision)
static SCIP_RETCODE	branchingResultDataCreate (SCIP *scip, BRANCHINGRESULTDATA **resultdata)
static void	branchingResultDataInit (SCIP *scip, BRANCHINGRESULTDATA *resultdata)
static void	branchingResultDataCopy (BRANCHINGRESULTDATA *sourcedata, BRANCHINGRESULTDATA *targetdata)
static void	branchingResultDataFree (SCIP *scip, BRANCHINGRESULTDATA **resultdata)
static SCIP_RETCODE	level2resultCreateFromData (SCIP *scip, LEVEL2DATA *data, LEVEL2RESULT **result)
static void	level2resultFree (SCIP *scip, LEVEL2RESULT **result)
static SCIP_Bool	level2resultEqual (LEVEL2RESULT *result1, LEVEL2RESULT *result2)
static SCIP_RETCODE	level2dataCreate (SCIP *scip, LEVEL2DATA **data)
static void	level2dataFree (SCIP *scip, LEVEL2DATA **data)
static SCIP_RETCODE	level2dataEnsureSize (SCIP *scip, LEVEL2DATA *data)
static SCIP_RETCODE	level2dataGetResult (SCIP *scip, LEVEL2DATA *data, LEVEL2RESULT **result)
static SCIP_RETCODE	level2dataStoreResult (SCIP *scip, LEVEL2DATA *data, SCIP_Real lpobjval, SCIP_Bool cutoff, SCIP_Bool valid, SCIP_Bool *duplicate)
static SCIP_RETCODE	constraintListCreate (SCIP *scip, CONSTRAINTLIST **conslist, int startsize)
static SCIP_RETCODE	constraintListAppend (SCIP *scip, CONSTRAINTLIST *list, SCIP_VAR **consvars, int nconsvars, SCIP_Bool violated)
static void	constraintListFree (SCIP *scip, CONSTRAINTLIST **conslist)
static SCIP_RETCODE	binaryVarListCreate (SCIP *scip, BINARYVARLIST **list, int startsize)
static void	binaryVarListAppend (SCIP *scip, BINARYVARLIST *list, SCIP_VAR *vartoadd)
static void	binaryVarListDrop (BINARYVARLIST *list)
static void	binaryVarListFree (SCIP *scip, BINARYVARLIST **list)
static SCIP_RETCODE	binConsDataCreate (SCIP *scip, BINCONSDATA **consdata, int maxdepth, int nstartcons)
static void	binConsDataFree (SCIP *scip, BINCONSDATA **consdata)
static SCIP_RETCODE	candidateListCreate (SCIP *scip, CANDIDATELIST **candidatelist, int ncandidates)
static SCIP_RETCODE	candidateListGetAllFractionalCandidates (SCIP *scip, CANDIDATELIST **candidatelist)
static SCIP_RETCODE	candidateListFree (SCIP *scip, CANDIDATELIST **candidatelist)
static SCIP_RETCODE	candidateListKeep (SCIP *scip, CANDIDATELIST *candidatelist, int nindices)
static SCIP_RETCODE	domainReductionsCreate (SCIP *scip, DOMAINREDUCTIONS **domreds)
static void	domainReductionsFree (SCIP *scip, DOMAINREDUCTIONS **domreds)
static SCIP_RETCODE	statusCreate (SCIP *scip, STATUS **status)
static void	statusFree (SCIP *scip, STATUS **status)
static void	scoreContainterResetBestSortedCands (SCORECONTAINER *scorecontainer)
static SCIP_RETCODE	scoreContainerCreate (SCIP *scip, SCORECONTAINER **scorecontainer, CONFIGURATION *config)
static int	findInsertionPoint (SCIP *scip, SCORECONTAINER *scorecontainer, SCIP_Real scoretoinsert, CANDIDATE **candidates, int ncandidates)
static CANDIDATE *	scoreContainerUpdateSortOrder (SCORECONTAINER *scorecontainer, CANDIDATE *candidate, int insertpoint)
static SCIP_RETCODE	scoreContainerSetScore (SCIP *scip, SCORECONTAINER *scorecontainer, CANDIDATE *cand, SCIP_Real score, SCIP_Real downgain, SCIP_Real upgain)
static SCIP_RETCODE	scoreContainerFree (SCIP *scip, SCORECONTAINER **scorecontainer)
static SCIP_RETCODE	selectVarRecursive (SCIP *scip, STATUS *status, PERSISTENTDATA *persistent, CONFIGURATION *config, SCIP_SOL *baselpsol, DOMAINREDUCTIONS *domainreductions, BINCONSDATA *binconsdata, CANDIDATELIST *candidatelist, BRANCHINGDECISION *decision, SCORECONTAINER *scorecontainer, LEVEL2DATA *level2data, int recursiondepth, SCIP_Real lpobjval, SCIP_Real baselpobjval, SCIP_Longint *niterations, int *ndeepestcutoffs, SCIP_Real *bestgain, SCIP_Real *totalgains, int *ntotalgains, int *ndeepestnodes)
static void	addLowerBound (SCIP *scip, SCIP_VAR *var, SCIP_Real lowerbound, SCIP_SOL *baselpsol, SCIP_Bool simplechange, DOMAINREDUCTIONS *domainreductions)
static void	addUpperBound (SCIP *scip, SCIP_VAR *var, SCIP_Real upperbound, SCIP_SOL *baselpsol, SCIP_Bool simplechange, DOMAINREDUCTIONS *domainreductions)
static void	applySingleDeeperDomainReductions (SCIP *scip, SCIP_SOL *baselpsol, int maxstoredomreds, DOMAINREDUCTIONS *targetdomreds, DOMAINREDUCTIONS *domreds)
static void	applyDeeperDomainReductions (SCIP *scip, SCIP_SOL *baselpsol, int maxstoredomreds, DOMAINREDUCTIONS *targetdomreds, DOMAINREDUCTIONS *downdomreds, DOMAINREDUCTIONS *updomreds)
static SCIP_RETCODE	applyDomainReductions (SCIP *scip, CONFIGURATION *config, SCIP_SOL *baselpsol, DOMAINREDUCTIONS *domreds, SCIP_Bool *domredcutoff, SCIP_Bool *domred)
static SCIP_RETCODE	copyCurrentSolution (SCIP *scip, SCIP_SOL **lpsol)
static SCIP_RETCODE	branchOnVar (SCIP *scip, CONFIGURATION *config, BRANCHINGDECISION *decision)
static SCIP_RETCODE	getNIterationsLastLP (SCIP *scip, SCIP_Longint *iterations)
static SCIP_RETCODE	executeBranching (SCIP *scip, CONFIGURATION *config, SCIP_Bool downbranching, CANDIDATE *candidate, BRANCHINGRESULTDATA *resultdata, SCIP_SOL *baselpsol, DOMAINREDUCTIONS *domreds, STATUS *status)
static SCIP_RETCODE	createBinaryConstraint (SCIP *scip, CONFIGURATION *config, SCIP_CONS **constraint, char *constraintname, SCIP_VAR **consvars, int nconsvars)
static void	createBinaryConstraintName (SCIP_VAR **binaryvars, int nbinaryvars, char *constraintname)
static SCIP_RETCODE	addBinaryConstraint (SCIP *scip, CONFIGURATION *config, BINCONSDATA *binconsdata, SCIP_SOL *baselpsol)
static SCIP_RETCODE	applyBinaryConstraints (SCIP *scip, SCIP_NODE *basenode, CONSTRAINTLIST *conslist, CONFIGURATION *config, SCIP_Bool *consadded, SCIP_Bool *cutoff, SCIP_Bool *boundchange)
static SCIP_Bool	areBoundsChanged (SCIP *scip, SCIP_VAR *var, SCIP_Real lowerbound, SCIP_Real upperbound)
static SCIP_Bool	isBranchFurther (STATUS *status, SCIP_Bool checkdomreds)
static SCIP_Bool	isBranchFurtherLoopDecrement (STATUS *status, int *loopcounter)
static SCIP_Bool	isUseOldBranching (SCIP *scip, PERSISTENTDATA *persistent, CONFIGURATION *config, SCIP_VAR *branchvar)
static SCIP_RETCODE	getOldBranching (SCIP *scip, PERSISTENTDATA *persistent, CONFIGURATION *config, SCIP_VAR *branchvar, BRANCHINGRESULTDATA *downbranchingresult, BRANCHINGRESULTDATA *upbranchingresult, SCIP_Real *oldlpobjval)
static SCIP_RETCODE	updateOldBranching (SCIP *scip, PERSISTENTDATA *persistent, CONFIGURATION *config, SCIP_VAR *branchvar, SCIP_Real branchval, BRANCHINGRESULTDATA *downbranchingresult, BRANCHINGRESULTDATA *upbranchingresult, SCIP_Real lpobjval)
static SCIP_RETCODE	getFSBResult (SCIP *scip, STATUS *status, PERSISTENTDATA *persistent, CONFIGURATION *config, SCIP_SOL *baselpsol, DOMAINREDUCTIONS *domainreductions, BINCONSDATA *binconsdata, CANDIDATELIST *candidatelist, BRANCHINGDECISION *decision, SCORECONTAINER *scorecontainer, LEVEL2DATA *level2data, SCIP_Real lpobjval)
static SCIP_Real	calculateScoreFromResult (SCIP *scip, SCIP_VAR *branchvar, BRANCHINGRESULTDATA *downbranchingresult, BRANCHINGRESULTDATA *upbranchingresult, SCIP_Real lpobjval)
static SCIP_Real	calculateScoreFromResult2 (SCIP *scip, SCIP_VAR *branchvar, BRANCHINGRESULTDATA *downbranchingresult, BRANCHINGRESULTDATA *upbranchingresult, SCIP_Real lpobjval)
static SCIP_Real	calculateScoreFromDeeperscore (SCIP *scip, SCIP_VAR *branchvar, BRANCHINGRESULTDATA *downbranchingresult, BRANCHINGRESULTDATA *upbranchingresult)
static SCIP_Real	calculateScoreFromDeeperscoreAndCutoffs (SCIP *scip, SCIP_VAR *branchvar, BRANCHINGRESULTDATA *downbranchingresult, BRANCHINGRESULTDATA *upbranchingresult)
static SCIP_Real	calculateWeightedGain (SCIP *scip, CONFIGURATION *config, BRANCHINGRESULTDATA *downbranchingresult, BRANCHINGRESULTDATA *upbranchingresult, SCIP_Real lpobjval)
static SCIP_Real	calculateScaledCutoffScore (BRANCHINGRESULTDATA *downbranchingresult, BRANCHINGRESULTDATA *upbranchingresult)
static SCIP_Real	calculateWeightedCutoffScore (CONFIGURATION *config, BRANCHINGRESULTDATA *downbranchingresult, BRANCHINGRESULTDATA *upbranchingresult)
static SCIP_Real	calculateCutoffScore (SCIP *scip, SCIP_VAR *branchvar, BRANCHINGRESULTDATA *downbranchingresult, BRANCHINGRESULTDATA *upbranchingresult, SCIP_Real lpobjval)
static SCIP_Real	calculateRelCutoffScore (SCIP *scip, SCIP_VAR *branchvar, BRANCHINGRESULTDATA *downbranchingresult, BRANCHINGRESULTDATA *upbranchingresult, SCIP_Real lpobjval)
static SCIP_Real	calculateScore (SCIP *scip, CONFIGURATION *config, SCIP_VAR *branchvar, BRANCHINGRESULTDATA *downbranchingresult, BRANCHINGRESULTDATA *upbranchingresult, SCIP_Real lpobjval, SCIP_Real baselpobjval)
static SCIP_Real	calculateScoreFromPseudocosts (SCIP *scip, CANDIDATE *lpcand)
static void	sortFirstCandidatesByScore (SCIP *scip, CANDIDATELIST *candidatelist, SCORECONTAINER *scorecontainer, int nbestcandidates)
static SCIP_Bool	isCandidateReliable (SCIP *scip, SCIP_VAR *branchvar)
static SCIP_Bool	isCurrentNodeCutoff (SCIP *scip)
static SCIP_RETCODE	ensureScoresPresent (SCIP *scip, STATUS *status, PERSISTENTDATA *persistent, CONFIGURATION *config, SCIP_SOL *baselpsol, DOMAINREDUCTIONS *domainreductions, BINCONSDATA *binconsdata, CANDIDATELIST *allcandidates, BRANCHINGDECISION *decision, SCORECONTAINER *scorecontainer, LEVEL2DATA *level2data, SCIP_Real lpobjval)
static SCIP_RETCODE	filterCandidates (SCIP *scip, STATUS *status, PERSISTENTDATA *persistent, CONFIGURATION *config, SCIP_SOL *baselpsol, DOMAINREDUCTIONS *domainreductions, BINCONSDATA *binconsdata, CANDIDATELIST *candidatelist, BRANCHINGDECISION *decision, SCORECONTAINER *scorecontainer, LEVEL2DATA *level2data, SCIP_Real lpobjval)
static SCIP_RETCODE	executeBranchingRecursive (SCIP *scip, STATUS *status, CONFIGURATION *config, SCIP_SOL *baselpsol, CANDIDATE *candidate, SCIP_Real localbaselpsolval, SCIP_Real baselpobjval, int recursiondepth, DOMAINREDUCTIONS *domainreductions, BINCONSDATA *binconsdata, LEVEL2DATA *level2data, BRANCHINGRESULTDATA *branchingresult, SCORECONTAINER *scorecontainer, SCIP_Bool downbranching)
static SCIP_Bool	isStoreDecision (CONFIGURATION *config, BINCONSDATA *binconsdata, DOMAINREDUCTIONS *domainreductions)
static SCIP_RETCODE	selectVarStart (SCIP *scip, CONFIGURATION *config, PERSISTENTDATA *persistent, STATUS *status, BRANCHINGDECISION *decision, SCORECONTAINER *scorecontainer, CANDIDATELIST *candidatelist)
static SCIP_Bool	isUsePreviousResult (SCIP *scip, SCIP_BRANCHRULEDATA *branchruledata)
static SCIP_RETCODE	usePreviousResult (SCIP *scip, SCIP_BRANCHRULEDATA *branchruledata, SCIP_RESULT *result)
static SCIP_RETCODE	freePersistent (SCIP *scip, SCIP_BRANCHRULEDATA *branchruledata)
static SCIP_RETCODE	initBranchruleData (SCIP *scip, SCIP_BRANCHRULEDATA *branchruledata)
static	SCIP_DECL_BRANCHCOPY (branchCopyLookahead)
static	SCIP_DECL_BRANCHFREE (branchFreeLookahead)
static	SCIP_DECL_BRANCHINIT (branchInitLookahead)
static	SCIP_DECL_BRANCHEXIT (branchExitLookahead)
static	SCIP_DECL_BRANCHEXITSOL (branchExitSolLookahead)
static	SCIP_DECL_BRANCHEXECLP (branchExeclpLookahead)
SCIP_RETCODE	SCIPincludeBranchruleLookahead (SCIP *scip)

Macro Definition Documentation

BRANCHRULE_NAME

#define BRANCHRULE_NAME   "lookahead"

Definition at line 85 of file branch_lookahead.c.

BRANCHRULE_DESC

#define BRANCHRULE_DESC   "full strong branching over multiple levels"

Definition at line 86 of file branch_lookahead.c.

BRANCHRULE_PRIORITY

#define BRANCHRULE_PRIORITY   0

Definition at line 87 of file branch_lookahead.c.

BRANCHRULE_MAXDEPTH

#define BRANCHRULE_MAXDEPTH   -1

Definition at line 88 of file branch_lookahead.c.

BRANCHRULE_MAXBOUNDDIST

#define BRANCHRULE_MAXBOUNDDIST   1.0

Definition at line 89 of file branch_lookahead.c.

DEFAULT_USEBINARYCONSTRAINTS

#define DEFAULT_USEBINARYCONSTRAINTS   FALSE

should binary constraints be collected and applied?

Definition at line 91 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_ADDCLIQUE

#define DEFAULT_ADDCLIQUE   FALSE

add binary constraints with two variables found at the root node also as a clique?

Definition at line 92 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_ADDBINCONSROW

#define DEFAULT_ADDBINCONSROW   0

should binary constraints be added as rows to the base LP? (0: no, 1: separate, 2: as initial rows)

Definition at line 93 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_USEDOMAINREDUCTION

#define DEFAULT_USEDOMAINREDUCTION   TRUE

Should domain reductions be collected and applied?

Definition at line 95 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_MERGEDOMAINREDUCTIONS

#define DEFAULT_MERGEDOMAINREDUCTIONS   FALSE

should domain reductions of feasible siblings should be merged?

Definition at line 96 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_PREFERSIMPLEBOUNDS

#define DEFAULT_PREFERSIMPLEBOUNDS   FALSE

should domain reductions only be applied if there are simple bound changes?

Definition at line 97 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_ONLYVIOLDOMREDS

#define DEFAULT_ONLYVIOLDOMREDS   FALSE

Should only domain reductions that violate the LP solution be applied?

Definition at line 98 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_MAXNVIOLATEDCONS

#define DEFAULT_MAXNVIOLATEDCONS   1

How many constraints that are violated by the base lp solution should be gathered until the rule is stopped and they are added?

Definition at line 99 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_MAXNVIOLATEDBINCONS

#define DEFAULT_MAXNVIOLATEDBINCONS   0

How many binary constraints that are violated by the base lp solution should be gathered until the rule is stopped and they are added?

Definition at line 101 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_MAXNVIOLATEDDOMREDS

#define DEFAULT_MAXNVIOLATEDDOMREDS   1

How many domain reductions that are violated by the base lp solution should be gathered until the rule is stopped and they are added?

Definition at line 104 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_STOREUNVIOLATEDSOL

#define DEFAULT_STOREUNVIOLATEDSOL   TRUE

If only non violating constraints are added, should the branching decision be stored till the next call?

Definition at line 106 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_REEVALAGE

#define DEFAULT_REEVALAGE   10LL

Max number of LPs solved after which a previous prob branching result is recalculated.

Definition at line 108 of file branch_lookahead.c.

DEFAULT_REEVALAGEFSB

#define DEFAULT_REEVALAGEFSB   10LL

Max number of LPs solved after which a previous FSB scoring result is recalculated.

Definition at line 110 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_RECURSIONDEPTH

#define DEFAULT_RECURSIONDEPTH   2

The max depth of LAB.

Definition at line 112 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_ADDNONVIOCONS

#define DEFAULT_ADDNONVIOCONS   FALSE

Should binary constraints, that are not violated by the base LP, be collected and added?

Definition at line 113 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_PROPAGATE

#define DEFAULT_PROPAGATE   TRUE

Should domain propagation be executed before each temporary node is solved?

Definition at line 115 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_USELEVEL2DATA

#define DEFAULT_USELEVEL2DATA   TRUE

should branching data generated at depth level 2 be stored for re-using it?

Definition at line 117 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_APPLYCHILDBOUNDS

#define DEFAULT_APPLYCHILDBOUNDS   FALSE

should bounds known for child nodes be applied?

Definition at line 118 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_ENFORCEMAXDOMREDS

#define DEFAULT_ENFORCEMAXDOMREDS   FALSE

should the maximum number of domain reductions maxnviolateddomreds be enforced?

Definition at line 119 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_UPDATEBRANCHINGRESULTS

#define DEFAULT_UPDATEBRANCHINGRESULTS   FALSE

should branching results (and scores) be updated w.r.t. proven dual bounds?

Definition at line 120 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_MAXPROPROUNDS

#define DEFAULT_MAXPROPROUNDS   0

maximum number of propagation rounds to perform at temporary nodes (-1: unlimited, 0: SCIP default)

Definition at line 121 of file branch_lookahead.c.

DEFAULT_ABBREVIATED

#define DEFAULT_ABBREVIATED   TRUE

Toggles the abbreviated LAB.

Definition at line 123 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_MAXNCANDS

#define DEFAULT_MAXNCANDS   4

If abbreviated: The max number of candidates to consider at the base node

Definition at line 124 of file branch_lookahead.c.

DEFAULT_MAXNDEEPERCANDS

#define DEFAULT_MAXNDEEPERCANDS   2

If abbreviated: The max number of candidates to consider per deeper node (0: same as base node)

Definition at line 125 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_REUSEBASIS

#define DEFAULT_REUSEBASIS   TRUE

If abbreviated: Should the information gathered to obtain the best candidates be reused?

Definition at line 127 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_ABBREVPSEUDO

#define DEFAULT_ABBREVPSEUDO   FALSE

If abbreviated: Use pseudo costs to estimate the score of a candidate.

Definition at line 129 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_LEVEL2AVGSCORE

#define DEFAULT_LEVEL2AVGSCORE   FALSE

should the average score be used for uninitialized scores in level 2?

Definition at line 131 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_LEVEL2ZEROSCORE

#define DEFAULT_LEVEL2ZEROSCORE   FALSE

should uninitialized scores be set to 0?

Definition at line 132 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_SCORINGFUNCTION

#define DEFAULT_SCORINGFUNCTION   'a'

scoring function to be used at the base level

Definition at line 133 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_DEEPERSCORINGFUNCTION

#define DEFAULT_DEEPERSCORINGFUNCTION   'x'

scoring function to be used at deeper levels

Definition at line 134 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_SCORINGSCORINGFUNCTION

#define DEFAULT_SCORINGSCORINGFUNCTION   'd'

scoring function to be used for FSB scoring

Definition at line 135 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_MINWEIGHT

#define DEFAULT_MINWEIGHT   0.8

default value for the weight of the minimum in the convex combination of two child gains (taken from the paper)

Definition at line 136 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_WORSEFACTOR

#define DEFAULT_WORSEFACTOR   -1.0

if the FSB score is of a candidate is worse than the best by this factor, skip this candidate (-1: disable)

Definition at line 138 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

DEFAULT_FILTERBYMAXGAIN

#define DEFAULT_FILTERBYMAXGAIN   FALSE

should lookahead branching only be applied if the max gain in level 1 is not uniquely that of the best candidate?

Definition at line 139 of file branch_lookahead.c.

Referenced by SCIPincludeBranchruleLookahead().

LABdebugMessage

#define LABdebugMessage	(		scip,
			lvl,
			... )

Definition at line 176 of file branch_lookahead.c.

Referenced by addBinaryConstraint(), applyBinaryConstraints(), applyDeeperDomainReductions(), applyDomainReductions(), branchOnVar(), candidateFree(), candidateFreeWarmStartInfo(), candidateListGetAllFractionalCandidates(), candidateLoadWarmStartInfo(), ensureScoresPresent(), executeBranching(), executeBranchingRecursive(), filterCandidates(), getOldBranching(), initBranchruleData(), isUsePreviousResult(), level2dataStoreResult(), SCIP_DECL_BRANCHEXECLP(), SCIP_DECL_BRANCHINIT(), scoreContainerSetScore(), selectVarRecursive(), selectVarStart(), sortFirstCandidatesByScore(), and usePreviousResult().

level2resultPrint

#define level2resultPrint	(		scip,
			result )

Definition at line 768 of file branch_lookahead.c.

Referenced by level2dataStoreResult().

Function Documentation

warmStartInfoCreate()

SCIP_RETCODE warmStartInfoCreate ( SCIP * scip, WARMSTARTINFO ** warmstartinfo )

static

Allocates the warm start information on the buffer and initializes it with default values.

Parameters

scip	SCIP data structure
warmstartinfo	the warmstartinfo to allocate and initialize

Definition at line 196 of file branch_lookahead.c.

References assert(), FALSE, NULL, SCIP_CALL, SCIP_OKAY, and SCIPallocBlockMemory.

Referenced by candidateStoreWarmStartInfo().

warmStartInfoIsAvailable()

SCIP_Bool warmStartInfoIsAvailable ( WARMSTARTINFO * warmstartinfo )

static

checks that the warm start info can be read into the lp solver.

Parameters

warmstartinfo

the warm start info to check (may be NULL)

Definition at line 216 of file branch_lookahead.c.

References WARMSTARTINFO::lpistate, NULL, and SCIP_Bool.

Referenced by candidateHasWarmStartInfo().

warmStartInfoFree()

SCIP_RETCODE warmStartInfoFree ( SCIP * scip, WARMSTARTINFO ** warmstartinfo )

static

Frees the allocated buffer memory of the warm start info.

Parameters

scip	SCIP data structure
warmstartinfo	the warm start info to free

Definition at line 225 of file branch_lookahead.c.

References assert(), NULL, SCIP_CALL, SCIP_OKAY, SCIPblkmem(), SCIPfreeBlockMemory, SCIPgetLPI(), SCIPlpiFreeNorms(), and SCIPlpiFreeState().

Referenced by candidateFreeWarmStartInfo().

candidateCreate()

SCIP_RETCODE candidateCreate ( SCIP * scip, CANDIDATE ** candidate )

static

Allocates the candidate on the buffer and initializes it with default values.

Parameters

scip	SCIP data structure
candidate	the candidate to allocate and initialize

Definition at line 266 of file branch_lookahead.c.

References assert(), NULL, SCIP_CALL, SCIP_OKAY, and SCIPallocBlockMemory.

Referenced by candidateListGetAllFractionalCandidates().

candidateFreeWarmStartInfo()

SCIP_RETCODE candidateFreeWarmStartInfo ( SCIP * scip, CANDIDATE * candidate )

static

free the warm starting information for the given candidate

Parameters

scip	SCIP data structure
candidate	the candidate to free the warm starting information for

Definition at line 285 of file branch_lookahead.c.

References assert(), CANDIDATE::branchvar, CANDIDATE::downwarmstartinfo, LABdebugMessage, NULL, SCIP_CALL, SCIP_OKAY, SCIP_VERBLEVEL_FULL, SCIPvarGetName(), CANDIDATE::upwarmstartinfo, and warmStartInfoFree().

Referenced by candidateFree(), and scoreContainerSetScore().

candidateFree()

SCIP_RETCODE candidateFree ( SCIP * scip, CANDIDATE ** candidate )

static

Frees the allocated buffer memory of the candidate and clears the contained lpi memories.

Parameters

scip	SCIP data structure
candidate	the candidate to free

Definition at line 312 of file branch_lookahead.c.

References assert(), candidateFreeWarmStartInfo(), LABdebugMessage, NULL, SCIP_CALL, SCIP_OKAY, SCIP_VERBLEVEL_FULL, SCIPfreeBlockMemory, and SCIPvarGetName().

Referenced by candidateListFree(), and candidateListKeep().

candidateStoreWarmStartInfo()

SCIP_RETCODE candidateStoreWarmStartInfo ( SCIP * scip, CANDIDATE * candidate, SCIP_Bool down )

static

Store the current lp solution in the warm start info for further usage.

Parameters

scip	SCIP data structure
candidate	the branching candidate
down	is the info for down branching?

Definition at line 333 of file branch_lookahead.c.

References assert(), CANDIDATE::downwarmstartinfo, WARMSTARTINFO::dualfeas, WARMSTARTINFO::lpinorms, WARMSTARTINFO::lpistate, NULL, WARMSTARTINFO::primalfeas, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIPblkmem(), SCIPgetLPI(), SCIPlpiGetNorms(), SCIPlpiGetState(), SCIPlpiIsDualFeasible(), SCIPlpiIsPrimalFeasible(), CANDIDATE::upwarmstartinfo, and warmStartInfoCreate().

Referenced by executeBranchingRecursive().

candidateHasWarmStartInfo()

SCIP_Bool candidateHasWarmStartInfo ( CANDIDATE * candidate, SCIP_Bool down )

static

returns whether the candidate has stored warm starting information for the given direction

Parameters

candidate	the branching candidate
down	is the info for down branching?

Definition at line 381 of file branch_lookahead.c.

References assert(), CANDIDATE::downwarmstartinfo, NULL, SCIP_Bool, CANDIDATE::upwarmstartinfo, and warmStartInfoIsAvailable().

Referenced by executeBranching().

candidateLoadWarmStartInfo()

SCIP_RETCODE candidateLoadWarmStartInfo ( SCIP * scip, CANDIDATE * candidate, SCIP_Bool down )

static

loads the warm starting information of the candidate for the given direction

Parameters

scip	SCIP data structure
candidate	the branching candidate
down	is the info for down branching?

Definition at line 394 of file branch_lookahead.c.

References assert(), CANDIDATE::downwarmstartinfo, WARMSTARTINFO::dualfeas, LABdebugMessage, WARMSTARTINFO::lpinorms, WARMSTARTINFO::lpistate, NULL, WARMSTARTINFO::primalfeas, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_VERBLEVEL_HIGH, SCIPsetProbingLPState(), and CANDIDATE::upwarmstartinfo.

Referenced by executeBranching().

branchingDecisionInit()

void branchingDecisionInit ( SCIP * scip, BRANCHINGDECISION * decision )

static

initialize a branching decsion with default values

Parameters

scip	SCIP data structure
decision	the decision to initialize

Definition at line 452 of file branch_lookahead.c.

References assert(), BRANCHINGDECISION::boundssize, BRANCHINGDECISION::boundsvalid, BRANCHINGDECISION::branchval, BRANCHINGDECISION::branchvar, BRANCHINGDECISION::downdb, BRANCHINGDECISION::downdbvalid, BRANCHINGDECISION::downlowerbounds, BRANCHINGDECISION::downupperbounds, FALSE, NULL, BRANCHINGDECISION::proveddb, SCIP_INVALID, SCIPinfinity(), BRANCHINGDECISION::score, BRANCHINGDECISION::updb, BRANCHINGDECISION::updbvalid, BRANCHINGDECISION::uplowerbounds, and BRANCHINGDECISION::upupperbounds.

Referenced by branchingDecisionCreate(), and initBranchruleData().

branchingDecisionCreate()

SCIP_RETCODE branchingDecisionCreate ( SCIP * scip, BRANCHINGDECISION ** decision )

static

allocates a branching decision in the buffer and initializes it with default values.

Parameters

scip	SCIP data structure
decision	pointer to the decision to allocate and initialize

Definition at line 479 of file branch_lookahead.c.

References assert(), branchingDecisionInit(), NULL, SCIP_CALL, SCIP_OKAY, and SCIPallocBuffer.

Referenced by executeBranchingRecursive(), and SCIP_DECL_BRANCHEXECLP().

branchingDecisionCopy()

void branchingDecisionCopy ( BRANCHINGDECISION * sourcedecision, BRANCHINGDECISION * targetdecision )

static

copies the data from the source branching decision storage to the target storage; this is used to store the most important information (i.e., the dual bounds obtained) so that it can be used in a subsequent call in case the LP solution did not change because we only added bound changes that did not forbid the current LP solution; however, we do not want to store all the domain changes for the two potential child nodes for this rare case, they will be identified when processing the child nodes anyway

Parameters

sourcedecision	the source branching decision
targetdecision	the target branching decision

Definition at line 502 of file branch_lookahead.c.

References assert(), BRANCHINGDECISION::boundssize, BRANCHINGDECISION::boundsvalid, BRANCHINGDECISION::branchval, BRANCHINGDECISION::branchvar, BRANCHINGDECISION::downdb, BRANCHINGDECISION::downdbvalid, BRANCHINGDECISION::downlowerbounds, BRANCHINGDECISION::downupperbounds, FALSE, NULL, BRANCHINGDECISION::proveddb, BRANCHINGDECISION::score, BRANCHINGDECISION::updb, BRANCHINGDECISION::updbvalid, BRANCHINGDECISION::uplowerbounds, and BRANCHINGDECISION::upupperbounds.

Referenced by selectVarStart().

branchingDecisionIsValid()

SCIP_Bool branchingDecisionIsValid ( BRANCHINGDECISION * decision )

static

Checks whether the given branching decision can be used to branch on.

Parameters

decision

the branching decision to check

Definition at line 529 of file branch_lookahead.c.

References assert(), BRANCHINGDECISION::branchvar, NULL, and SCIP_Bool.

Referenced by isUsePreviousResult(), SCIP_DECL_BRANCHEXECLP(), and selectVarStart().

branchingDecisionEnsureBoundArraysSize()

SCIP_RETCODE branchingDecisionEnsureBoundArraysSize ( SCIP * scip, BRANCHINGDECISION * decision, int nvars )

static

Parameters

scip	SCIP data structure
decision	branching decision
nvars	number of problem variables

Definition at line 541 of file branch_lookahead.c.

References assert(), BRANCHINGDECISION::boundssize, BRANCHINGDECISION::downlowerbounds, BRANCHINGDECISION::downupperbounds, NULL, nvars, SCIP_CALL, SCIP_OKAY, SCIPallocBlockMemoryArray, BRANCHINGDECISION::uplowerbounds, and BRANCHINGDECISION::upupperbounds.

Referenced by selectVarRecursive().

branchingDecisionFree()

void branchingDecisionFree ( SCIP * scip, BRANCHINGDECISION ** decision )

static

Frees the allocated memory of the branching decision.

Parameters

scip	SCIP data structure
decision	pointer to the decision to be freed

Definition at line 564 of file branch_lookahead.c.

References assert(), NULL, SCIPfreeBlockMemoryArray, and SCIPfreeBuffer.

Referenced by executeBranchingRecursive(), and SCIP_DECL_BRANCHEXECLP().

branchingResultDataCreate()

SCIP_RETCODE branchingResultDataCreate ( SCIP * scip, BRANCHINGRESULTDATA ** resultdata )

static

Allocates a branching result in the buffer.

Parameters

scip	SCIP data structure
resultdata	pointer to the result to be allocated

Definition at line 609 of file branch_lookahead.c.

References assert(), NULL, SCIP_CALL, SCIP_OKAY, and SCIPallocBuffer.

Referenced by selectVarRecursive().

branchingResultDataInit()

void branchingResultDataInit ( SCIP * scip, BRANCHINGRESULTDATA * resultdata )

static

Initiates the branching result with default values.

Parameters

scip	SCIP data structure
resultdata	pointer to the result to be initialized

Definition at line 624 of file branch_lookahead.c.

References assert(), BRANCHINGRESULTDATA::bestgain, BRANCHINGRESULTDATA::cutoff, BRANCHINGRESULTDATA::deeperscore, BRANCHINGRESULTDATA::dualbound, BRANCHINGRESULTDATA::dualboundvalid, FALSE, BRANCHINGRESULTDATA::ndeepestcutoffs, BRANCHINGRESULTDATA::ndeepestnodes, BRANCHINGRESULTDATA::niterations, BRANCHINGRESULTDATA::ntotalgains, NULL, BRANCHINGRESULTDATA::objval, SCIPinfinity(), and BRANCHINGRESULTDATA::totalgains.

Referenced by selectVarRecursive().

branchingResultDataCopy()

void branchingResultDataCopy ( BRANCHINGRESULTDATA * sourcedata, BRANCHINGRESULTDATA * targetdata )

static

Copies the data from the source to the target.

Parameters

sourcedata	the source branching result
targetdata	the target branching result

Definition at line 647 of file branch_lookahead.c.

References assert(), BRANCHINGRESULTDATA::bestgain, BRANCHINGRESULTDATA::cutoff, BRANCHINGRESULTDATA::deeperscore, BRANCHINGRESULTDATA::dualbound, BRANCHINGRESULTDATA::dualboundvalid, BRANCHINGRESULTDATA::ndeepestcutoffs, BRANCHINGRESULTDATA::ndeepestnodes, BRANCHINGRESULTDATA::niterations, BRANCHINGRESULTDATA::ntotalgains, NULL, BRANCHINGRESULTDATA::objval, and BRANCHINGRESULTDATA::totalgains.

Referenced by getOldBranching(), selectVarRecursive(), and updateOldBranching().

branchingResultDataFree()

void branchingResultDataFree ( SCIP * scip, BRANCHINGRESULTDATA ** resultdata )

static

Frees the allocated buffer memory of the branching result.

Parameters

scip	SCIP data structure
resultdata	pointer to the result to be freed

Definition at line 670 of file branch_lookahead.c.

References assert(), NULL, and SCIPfreeBuffer.

Referenced by selectVarRecursive().

level2resultCreateFromData()

SCIP_RETCODE level2resultCreateFromData ( SCIP * scip, LEVEL2DATA * data, LEVEL2RESULT ** result )

static

allocates a double branching result in the memory and fills it with the information stored in the level 2 data

Parameters

scip	SCIP data structure
data	level2 data
result	pointer to the result to be allocated

Definition at line 712 of file branch_lookahead.c.

References assert(), LEVEL2DATA::branchdir1, LEVEL2DATA::branchdir2, LEVEL2DATA::branchval1, LEVEL2DATA::branchval2, LEVEL2DATA::branchvar1, LEVEL2DATA::branchvar2, NULL, result, SCIP_CALL, SCIP_OKAY, and SCIPallocBlockMemory.

Referenced by level2dataGetResult(), and level2dataStoreResult().

level2resultFree()

void level2resultFree ( SCIP * scip, LEVEL2RESULT ** result )

static

frees the allocated memory of the double branching result

Parameters

scip	SCIP data structure
result	pointer to the result to be freed

Definition at line 773 of file branch_lookahead.c.

References assert(), NULL, result, and SCIPfreeBlockMemory.

Referenced by level2dataFree(), and level2dataGetResult().

level2resultEqual()

SCIP_Bool level2resultEqual ( LEVEL2RESULT * result1, LEVEL2RESULT * result2 )

static

returns TRUE iff both level 2 results are equal; two branchings are equal if they branched on the same variables with the same values

Parameters

result1	first level 2 result
result2	second level 2 result

Definition at line 788 of file branch_lookahead.c.

References assert(), LEVEL2RESULT::branchdir1, LEVEL2RESULT::branchdir2, LEVEL2RESULT::branchval1, LEVEL2RESULT::branchval2, LEVEL2RESULT::branchvar1, LEVEL2RESULT::branchvar2, FALSE, SCIP_Bool, and TRUE.

Referenced by level2dataGetResult(), and level2dataStoreResult().

level2dataCreate()

SCIP_RETCODE level2dataCreate ( SCIP * scip, LEVEL2DATA ** data )

static

allocates the level2 data

Parameters

scip	SCIP data structure
data	pointer to the data to be allocated

Definition at line 812 of file branch_lookahead.c.

References assert(), NULL, SCIP_CALL, SCIP_OKAY, SCIPallocBlockMemory, and SCIPinfinity().

Referenced by selectVarStart().

level2dataFree()

void level2dataFree ( SCIP * scip, LEVEL2DATA ** data )

static

frees the allocated memory of the level2 data

Parameters

scip	SCIP data structure
data	pointer to the data to be freed

Definition at line 837 of file branch_lookahead.c.

References assert(), level2resultFree(), NULL, SCIPfreeBlockMemory, and SCIPfreeBlockMemoryArray.

Referenced by selectVarStart().

level2dataEnsureSize()

SCIP_RETCODE level2dataEnsureSize ( SCIP * scip, LEVEL2DATA * data )

static

ensures that level2results can store at least one more element

Parameters

scip	SCIP data structure
data	level2 data

Definition at line 862 of file branch_lookahead.c.

References assert(), LEVEL2DATA::level2results, LEVEL2DATA::level2resultssize, LEVEL2DATA::nlevel2results, NULL, SCIP_CALL, SCIP_OKAY, SCIPcalcMemGrowSize(), and SCIPreallocBlockMemoryArray.

Referenced by level2dataStoreResult().

level2dataGetResult()

SCIP_RETCODE level2dataGetResult ( SCIP * scip, LEVEL2DATA * data, LEVEL2RESULT ** result )

static

get a result from the level 2 data

Parameters

scip	SCIP data structure
data	level2 data
result	pointer to store result

Definition at line 883 of file branch_lookahead.c.

References assert(), LEVEL2DATA::branchvar1, LEVEL2DATA::branchvar2, i, level2resultCreateFromData(), level2resultEqual(), level2resultFree(), LEVEL2DATA::level2results, LEVEL2DATA::nlevel2results, NULL, result, SCIP_CALL, SCIP_OKAY, SCIP_VARTYPE_BINARY, SCIPgetVars(), SCIPvarGetType(), and SCIPvarIsImpliedIntegral().

Referenced by executeBranchingRecursive().

level2dataStoreResult()

SCIP_RETCODE level2dataStoreResult ( SCIP * scip, LEVEL2DATA * data, SCIP_Real lpobjval, SCIP_Bool cutoff, SCIP_Bool valid, SCIP_Bool * duplicate )

static

store a new result in the level 2 data

Parameters

scip	SCIP data structure
data	level2 data
lpobjval	LP objective value
cutoff	was the LP infeasible?
valid	is the LP value a valid dual bound?
duplicate	pointer to store whether information for the same branching decisions was already stored

Definition at line 924 of file branch_lookahead.c.

References assert(), LEVEL2DATA::branchvar1, LEVEL2DATA::branchvar2, cutoff, FALSE, i, LABdebugMessage, level2dataEnsureSize(), level2resultCreateFromData(), level2resultEqual(), level2resultPrint, LEVEL2DATA::level2results, LEVEL2DATA::level2resultssize, LEVEL2DATA::nlevel2results, NULL, result, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIP_VARTYPE_BINARY, SCIP_VERBLEVEL_HIGH, SCIPgetVars(), SCIPvarGetType(), SCIPvarIsImpliedIntegral(), TRUE, and valid.

Referenced by executeBranchingRecursive().

constraintListCreate()

SCIP_RETCODE constraintListCreate ( SCIP * scip, CONSTRAINTLIST ** conslist, int startsize )

static

Allocate and initialize the list holding the constraints.

Parameters

scip	SCIP data structure
conslist	Pointer to the list to be allocated and initialized.
startsize	The number of entries the list initially can hold.

Definition at line 1356 of file branch_lookahead.c.

References assert(), NULL, SCIP_CALL, SCIP_OKAY, SCIPallocBlockMemoryArray, and SCIPallocBuffer.

Referenced by binConsDataCreate().

constraintListAppend()

SCIP_RETCODE constraintListAppend ( SCIP * scip, CONSTRAINTLIST * list, SCIP_VAR ** consvars, int nconsvars, SCIP_Bool violated )

static

Append an element to the end of the list of constraints.

Parameters

scip	SCIP data structure
list	list to add the consvars to
consvars	array of variables for the constraint to be created later
nconsvars	number of elements in 'consvars'
violated	indicates whether the constraint is violated by the base lp

Definition at line 1381 of file branch_lookahead.c.

References assert(), CONSTRAINTLIST::consvars, CONSTRAINTLIST::memorysize, CONSTRAINTLIST::nconsvars, CONSTRAINTLIST::nelements, NULL, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIPcalcMemGrowSize(), SCIPduplicateBlockMemoryArray, SCIPreallocBlockMemoryArray, and CONSTRAINTLIST::violated.

Referenced by addBinaryConstraint().

constraintListFree()

void constraintListFree ( SCIP * scip, CONSTRAINTLIST ** conslist )

static

Free all resources of a constraint list in opposite order to the allocation.

Parameters

scip	SCIP data structure
conslist	Pointer to the list to be freed.

Definition at line 1416 of file branch_lookahead.c.

References assert(), i, NULL, SCIPfreeBlockMemoryArray, and SCIPfreeBuffer.

Referenced by binConsDataFree().

binaryVarListCreate()

SCIP_RETCODE binaryVarListCreate ( SCIP * scip, BINARYVARLIST ** list, int startsize )

static

Allocates and initializes the BINARYVARLIST struct.

Parameters

scip	SCIP data structure
list	Pointer to the list to be allocated and initialized.
startsize	The number of entries the list initially can hold.

Definition at line 1453 of file branch_lookahead.c.

References assert(), NULL, SCIP_CALL, SCIP_OKAY, SCIPallocBuffer, and SCIPallocBufferArray.

Referenced by binConsDataCreate().

binaryVarListAppend()

void binaryVarListAppend ( SCIP * scip, BINARYVARLIST * list, SCIP_VAR * vartoadd )

static

Appends a binary variable to the list, reallocating the list if necessary.

Parameters

scip	SCIP data structure
list	The list to add the var to.
vartoadd	The binary var to add to the list.

Definition at line 1475 of file branch_lookahead.c.

References assert(), BINARYVARLIST::binaryvars, BINARYVARLIST::memorysize, BINARYVARLIST::nbinaryvars, NULL, and SCIPvarIsBinary().

Referenced by executeBranchingRecursive().

binaryVarListDrop()

void binaryVarListDrop ( BINARYVARLIST * list )

static

Remove the last element from the list.

Parameters

list	The list to remove the last element from.

Definition at line 1494 of file branch_lookahead.c.

References assert(), BINARYVARLIST::binaryvars, BINARYVARLIST::nbinaryvars, and NULL.

Referenced by executeBranchingRecursive().

binaryVarListFree()

void binaryVarListFree ( SCIP * scip, BINARYVARLIST ** list )

static

Frees all resources allocated by a BINARYVARLIST in opposite order of allocation.

Parameters

scip	SCIP data structure
list	Pointer to the list to free

Definition at line 1508 of file branch_lookahead.c.

References assert(), NULL, SCIPfreeBuffer, and SCIPfreeBufferArray.

Referenced by binConsDataFree().

binConsDataCreate()

SCIP_RETCODE binConsDataCreate ( SCIP * scip, BINCONSDATA ** consdata, int maxdepth, int nstartcons )

static

Allocate and initialize the BINCONSDATA struct.

Parameters

scip	SCIP data structure
consdata	Pointer to the struct to be allocated and initialized.
maxdepth	The depth of the recursion as an upper bound of branch vars to hold.
nstartcons	The start size of the array containing the constraints.

Definition at line 1529 of file branch_lookahead.c.

References assert(), binaryVarListCreate(), constraintListCreate(), maxdepth, NULL, SCIP_CALL, SCIP_OKAY, and SCIPallocBuffer.

Referenced by selectVarStart().

binConsDataFree()

void binConsDataFree ( SCIP * scip, BINCONSDATA ** consdata )

static

Free all resources in a BINCONSDATA in opposite order of allocation.

Parameters

scip	SCIP data structure
consdata	Pointer to the struct to be freed.

Definition at line 1550 of file branch_lookahead.c.

References assert(), binaryVarListFree(), constraintListFree(), NULL, and SCIPfreeBuffer.

Referenced by selectVarStart().

candidateListCreate()

SCIP_RETCODE candidateListCreate ( SCIP * scip, CANDIDATELIST ** candidatelist, int ncandidates )

static

allocates the candidate list on the buffer WITHOUT initializing the contained array of candidates.

Parameters

scip	SCIP data structure
candidatelist	the candidate list to allocate
ncandidates	the number of candidates the list must hold

Definition at line 1574 of file branch_lookahead.c.

References assert(), NULL, SCIP_CALL, SCIP_OKAY, SCIPallocBuffer, and SCIPallocBufferArray.

Referenced by candidateListGetAllFractionalCandidates(), and ensureScoresPresent().

candidateListGetAllFractionalCandidates()

SCIP_RETCODE candidateListGetAllFractionalCandidates ( SCIP * scip, CANDIDATELIST ** candidatelist )

static

allocates the given list and fills it with all fractional candidates of the current LP solution.

Parameters

scip	SCIP data structure
candidatelist	the list to allocate and fill

Definition at line 1600 of file branch_lookahead.c.

References assert(), CANDIDATE::branchval, CANDIDATE::branchvar, candidateCreate(), candidateListCreate(), CANDIDATE::fracval, i, LABdebugMessage, lpcands, lpcandsfrac, lpcandssol, nlpcands, NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIP_VERBLEVEL_FULL, SCIPgetLPBranchCands(), and SCIPvarGetName().

Referenced by executeBranchingRecursive(), and SCIP_DECL_BRANCHEXECLP().

candidateListFree()

SCIP_RETCODE candidateListFree ( SCIP * scip, CANDIDATELIST ** candidatelist )

static

frees the allocated buffer memory of the candidate list and frees the contained candidates.

Parameters

scip	SCIP data structure
candidatelist	the list to be freed

Definition at line 1645 of file branch_lookahead.c.

References assert(), candidateFree(), i, NULL, SCIP_CALL, SCIP_OKAY, SCIPfreeBuffer, and SCIPfreeBufferArray.

Referenced by ensureScoresPresent(), executeBranchingRecursive(), and SCIP_DECL_BRANCHEXECLP().

candidateListKeep()

SCIP_RETCODE candidateListKeep ( SCIP * scip, CANDIDATELIST * candidatelist, int nindices )

static

keeps only the first candidates and frees the remaining ones

Parameters

scip	SCIP data structure
candidatelist	the list to allocate and fill
nindices	the number of candidates to keep (starting from 0)

Definition at line 1676 of file branch_lookahead.c.

References assert(), candidateFree(), CANDIDATELIST::candidates, i, CANDIDATELIST::ncandidates, NULL, SCIP_CALL, and SCIP_OKAY.

Referenced by filterCandidates().

domainReductionsCreate()

SCIP_RETCODE domainReductionsCreate ( SCIP * scip, DOMAINREDUCTIONS ** domreds )

static

allocate the struct on the buffer and initialize it with the default values

Parameters

scip	SCIP data structure
domreds	The struct that has to be allocated and initialized.

Definition at line 1723 of file branch_lookahead.c.

References assert(), NULL, SCIP_CALL, SCIP_OKAY, SCIPallocBuffer, SCIPallocBufferArray, SCIPallocClearBufferArray, SCIPgetNVars(), SCIPgetVars(), SCIPvarGetLbLocal(), SCIPvarGetUbLocal(), and vars.

Referenced by selectVarRecursive(), and selectVarStart().

domainReductionsFree()

void domainReductionsFree ( SCIP * scip, DOMAINREDUCTIONS ** domreds )

static

frees the given DOMAINREDUCTIONS and all contained Arrays in the opposite order of allocation

Parameters

scip	SCIP data structure
domreds	Pointer to the struct to be freed.

Definition at line 1765 of file branch_lookahead.c.

References assert(), NULL, SCIPfreeBuffer, and SCIPfreeBufferArray.

Referenced by selectVarRecursive(), and selectVarStart().

statusCreate()

SCIP_RETCODE statusCreate ( SCIP * scip, STATUS ** status )

static

Allocates the status on the buffer memory and initializes it with default values.

Parameters

scip	SCIP data structure
status	the status to be allocated

Definition at line 1799 of file branch_lookahead.c.

References assert(), FALSE, NULL, SCIP_CALL, SCIP_OKAY, and SCIPallocBuffer.

Referenced by executeBranchingRecursive(), and SCIP_DECL_BRANCHEXECLP().

statusFree()

void statusFree ( SCIP * scip, STATUS ** status )

static

frees the allocated buffer memory of the status

Parameters

scip	SCIP data structure
status	the status to be freed

Definition at line 1823 of file branch_lookahead.c.

References assert(), NULL, and SCIPfreeBuffer.

Referenced by executeBranchingRecursive(), and SCIP_DECL_BRANCHEXECLP().

scoreContainterResetBestSortedCands()

void scoreContainterResetBestSortedCands ( SCORECONTAINER * scorecontainer )

static

resets the array containing the sorted indices w.r.t. their score.

Parameters

scorecontainer

the score container to reset

Definition at line 1847 of file branch_lookahead.c.

References assert(), SCORECONTAINER::bestsortedcands, BMSclearMemoryArray, SCORECONTAINER::nbestsortedcands, and NULL.

Referenced by ensureScoresPresent(), and scoreContainerCreate().

scoreContainerCreate()

SCIP_RETCODE scoreContainerCreate ( SCIP * scip, SCORECONTAINER ** scorecontainer, CONFIGURATION * config )

static

allocates the score container and inits it with default values

Parameters

scip	SCIP data structure
scorecontainer	pointer to the score container to init
config	config struct with the user configuration

Definition at line 1858 of file branch_lookahead.c.

References assert(), i, CONFIGURATION::maxncands, NULL, SCIP_CALL, SCIP_OKAY, SCIPallocBuffer, SCIPallocBufferArray, SCIPgetNContImplVars(), SCIPgetNContVars(), SCIPgetNVars(), and scoreContainterResetBestSortedCands().

Referenced by SCIP_DECL_BRANCHEXECLP().

findInsertionPoint()

int findInsertionPoint ( SCIP * scip, SCORECONTAINER * scorecontainer, SCIP_Real scoretoinsert, CANDIDATE ** candidates, int ncandidates )

static

Finds the insertion index for the given score in the candidate list. The score of each candidate is taken from the scorecontainer. The first elements of the candidate list have to be sorted, as this method uses binary search to find the correct insertion point

Parameters

scip	SCIP data structure
scorecontainer	container with all the scores for each candidate
scoretoinsert	score to find the insertion index for
candidates	candidate list where the first nsorted elements are sorted (w.r.t. their score)
ncandidates	number of elements in candidates to consider, starting from 0

Definition at line 1906 of file branch_lookahead.c.

References assert(), CANDIDATE::branchvar, NULL, SCIP_Real, SCIPinfinity(), SCIPisGT(), SCIPvarGetProbindex(), and SCORECONTAINER::scores.

Referenced by scoreContainerSetScore(), and sortFirstCandidatesByScore().

scoreContainerUpdateSortOrder()

CANDIDATE * scoreContainerUpdateSortOrder ( SCORECONTAINER * scorecontainer, CANDIDATE * candidate, int insertpoint )

static

Inserts the given probindex into the sorted array in the container, moving all indices after it to the right. Then returns the element that does not fit into the array any longer.

Parameters

scorecontainer	container to insert the index into
candidate	the probindex of a variable to store
insertpoint	point to store the index at

Definition at line 1951 of file branch_lookahead.c.

References assert(), SCORECONTAINER::bestsortedcands, i, SCORECONTAINER::nbestsortedcands, and NULL.

Referenced by scoreContainerSetScore().

scoreContainerSetScore()

SCIP_RETCODE scoreContainerSetScore ( SCIP * scip, SCORECONTAINER * scorecontainer, CANDIDATE * cand, SCIP_Real score, SCIP_Real downgain, SCIP_Real upgain )

static

sets the score for the variable in the score container

Parameters

scip	SCIP data structure
scorecontainer	the container to write into
cand	candidate to add the score for
score	score to add
downgain	LP gain in down child
upgain	LP gain in up child

Definition at line 1976 of file branch_lookahead.c.

References assert(), SCORECONTAINER::bestsortedcands, CANDIDATE::branchvar, candidateFreeWarmStartInfo(), SCORECONTAINER::downgains, findInsertionPoint(), LABdebugMessage, SCORECONTAINER::nbestsortedcands, SCORECONTAINER::nsetscores, NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIP_VERBLEVEL_HIGH, SCIPisGE(), SCIPvarGetName(), SCIPvarGetProbindex(), scoreContainerUpdateSortOrder(), SCORECONTAINER::scores, SCORECONTAINER::scoresum, and SCORECONTAINER::upgains.

Referenced by ensureScoresPresent(), and selectVarRecursive().

scoreContainerFree()

SCIP_RETCODE scoreContainerFree ( SCIP * scip, SCORECONTAINER ** scorecontainer )

static

Frees the score container and all of its contained arrays.

Parameters

scip	SCIP data structure
scorecontainer	score container to free

Definition at line 2033 of file branch_lookahead.c.

References assert(), NULL, SCIP_OKAY, SCIPfreeBuffer, and SCIPfreeBufferArray.

Referenced by SCIP_DECL_BRANCHEXECLP().

selectVarRecursive()

SCIP_RETCODE selectVarRecursive ( SCIP * scip, STATUS * status, PERSISTENTDATA * persistent, CONFIGURATION * config, SCIP_SOL * baselpsol, DOMAINREDUCTIONS * domainreductions, BINCONSDATA * binconsdata, CANDIDATELIST * candidatelist, BRANCHINGDECISION * decision, SCORECONTAINER * scorecontainer, LEVEL2DATA * level2data, int recursiondepth, SCIP_Real lpobjval, SCIP_Real baselpobjval, SCIP_Longint * niterations, int * ndeepestcutoffs, SCIP_Real * bestgain, SCIP_Real * totalgains, int * ntotalgains, int * ndeepestnodes )

static

branches recursively on all given candidates

Parameters

scip	SCIP data structure
status	current status
persistent	container to store data over multiple calls to the branching rule; or NULL
config	the configuration of the branching rule
baselpsol	base lp solution
domainreductions	container collecting all domain reductions found
binconsdata	container collecting all binary constraints
candidatelist	list of candidates to branch on
decision	struct to store the final decision
scorecontainer	container to retrieve already calculated scores
level2data	level 2 LP results data
recursiondepth	remaining recursion depth
lpobjval	LP objective value of current probing node
baselpobjval	LP objective value of focus node (not probing)
niterations	pointer to store the total number of iterations for this variable
ndeepestcutoffs	pointer to store the total number of cutoffs on the deepest level
bestgain	pointer to store the best gain found with these candidates
totalgains	pointer to store the sum over all gains that are valid in both children
ntotalgains	pointer to store the number of gains summed in totalgains
ndeepestnodes	pointer to store the number of nodes processed in the deepest level

Definition at line 4710 of file branch_lookahead.c.

References CONFIGURATION::abbreviated, addLowerBound(), addUpperBound(), applyDeeperDomainReductions(), applySingleDeeperDomainReductions(), areBoundsChanged(), assert(), BMScopyMemoryArray, BRANCHINGDECISION::boundsvalid, branchingDecisionEnsureBoundArraysSize(), branchingResultDataCopy(), branchingResultDataCreate(), branchingResultDataFree(), branchingResultDataInit(), BRANCHINGDECISION::branchval, CANDIDATE::branchval, BRANCHINGDECISION::branchvar, CANDIDATE::branchvar, c, calculateScore(), CANDIDATELIST::candidates, BINCONSDATA::conslist, BRANCHINGRESULTDATA::cutoff, STATUS::cutoff, domainReductionsCreate(), domainReductionsFree(), STATUS::domred, BRANCHINGDECISION::downdb, BRANCHINGDECISION::downdbvalid, BRANCHINGDECISION::downlowerbounds, BRANCHINGDECISION::downupperbounds, BRANCHINGRESULTDATA::dualbound, BRANCHINGRESULTDATA::dualboundvalid, CONFIGURATION::enforcemaxdomreds, executeBranchingRecursive(), FALSE, getOldBranching(), i, CONFIGURATION::inscoring, isBranchFurtherLoopDecrement(), isUseOldBranching(), LABdebugMessage, STATUS::limitreached, DOMAINREDUCTIONS::lowerbounds, STATUS::lperror, MAX, STATUS::maxnconsreached, CONFIGURATION::maxnviolatedbincons, CONFIGURATION::maxnviolatedcons, CONFIGURATION::maxnviolateddomreds, CONFIGURATION::mergedomainreductions, MIN, CANDIDATELIST::ncandidates, DOMAINREDUCTIONS::nchangedvars, BRANCHINGRESULTDATA::ndeepestcutoffs, BRANCHINGRESULTDATA::ndeepestnodes, CONSTRAINTLIST::nelements, BRANCHINGRESULTDATA::niterations, nlpcands, DOMAINREDUCTIONS::nsimplebounds, NULL, nvars, CONSTRAINTLIST::nviolatedcons, DOMAINREDUCTIONS::nviolatedvars, BRANCHINGRESULTDATA::objval, CONFIGURATION::prefersimplebounds, BRANCHINGDECISION::proveddb, PERSISTENTDATA::restartindex, SCIP_Bool, SCIP_CALL, SCIP_Longint, SCIP_OKAY, SCIP_Real, SCIP_VERBLEVEL_FULL, SCIP_VERBLEVEL_HIGH, SCIP_VERBLEVEL_NORMAL, SCIPallColsInLP(), SCIPgetBoolParam(), SCIPgetCutoffbound(), SCIPgetLPI(), SCIPgetNVars(), SCIPgetProbingDepth(), SCIPinfinity(), SCIPisEQ(), SCIPisGE(), SCIPisGT(), SCIPisRelGT(), SCIPisStopped(), SCIPisStrongbranchDownFirst(), SCIPvarGetLbLocal(), SCIPvarGetName(), SCIPvarGetUbLocal(), BRANCHINGDECISION::score, scoreContainerSetScore(), TRUE, CONFIGURATION::updatebranchingresults, updateOldBranching(), BRANCHINGDECISION::updb, BRANCHINGDECISION::updbvalid, BRANCHINGDECISION::uplowerbounds, DOMAINREDUCTIONS::upperbounds, BRANCHINGDECISION::upupperbounds, and CONFIGURATION::usedomainreduction.

Referenced by executeBranchingRecursive(), getFSBResult(), and selectVarStart().

addLowerBound()

void addLowerBound ( SCIP * scip, SCIP_VAR * var, SCIP_Real lowerbound, SCIP_SOL * baselpsol, SCIP_Bool simplechange, DOMAINREDUCTIONS * domainreductions )

static

Adds the given lower bound to the DOMAINREDUCTIONS struct.

Parameters

scip	SCIP data structure
var	The variable the bound should be added for.
lowerbound	The new lower bound for the variable.
baselpsol	The LP solution of the base problem. Used to check whether the domain reduction is violated by it.
simplechange	does the change result from an infeasible child node?
domainreductions	The struct the domain reduction should be added to.

Definition at line 2088 of file branch_lookahead.c.

References assert(), NULL, SCIP_Bool, SCIP_Real, SCIPadjustedVarLb(), SCIPgetSolVal(), SCIPisEQ(), SCIPisFeasGT(), SCIPisLT(), SCIPvarGetProbindex(), TRUE, and var.

Referenced by applyDeeperDomainReductions(), applySingleDeeperDomainReductions(), executeBranching(), and selectVarRecursive().

addUpperBound()

void addUpperBound ( SCIP * scip, SCIP_VAR * var, SCIP_Real upperbound, SCIP_SOL * baselpsol, SCIP_Bool simplechange, DOMAINREDUCTIONS * domainreductions )

static

Adds the given upper bound to the DOMAINREDUCTIONS struct.

Parameters

scip	SCIP data structure
var	The variable the bound should be added for.
upperbound	The new upper bound for the variable.
baselpsol	The LP solution of the base problem. Used to check whether the domain reduction is violated by it.
simplechange	does the change result from an infeasible child node?
domainreductions	The struct the domain reduction should be added to.

Definition at line 2153 of file branch_lookahead.c.

References assert(), NULL, SCIP_Bool, SCIP_Real, SCIPadjustedVarUb(), SCIPgetSolVal(), SCIPisEQ(), SCIPisFeasLT(), SCIPisLE(), SCIPvarGetProbindex(), TRUE, and var.

Referenced by applyDeeperDomainReductions(), applySingleDeeperDomainReductions(), executeBranching(), and selectVarRecursive().

applySingleDeeperDomainReductions()

void applySingleDeeperDomainReductions ( SCIP * scip, SCIP_SOL * baselpsol, int maxstoredomreds, DOMAINREDUCTIONS * targetdomreds, DOMAINREDUCTIONS * domreds )

static

apply the domain reductions from a single struct to another one; this may be used in case one of the two child problems of a variable is infeasible

Parameters

scip	SCIP data structure
baselpsol	The LP solution of the base problem. Used to check whether the domain reduction is violated by it.
maxstoredomreds	maximum number of domain reductions to store
targetdomreds	The target that should be filled with the merged data.
domreds	source domain reductions

Definition at line 2222 of file branch_lookahead.c.

References addLowerBound(), addUpperBound(), assert(), FALSE, i, DOMAINREDUCTIONS::lowerbounds, NULL, nvars, DOMAINREDUCTIONS::nviolatedvars, SCIPgetNVars(), SCIPgetVars(), TRUE, DOMAINREDUCTIONS::upperbounds, and vars.

Referenced by selectVarRecursive().

applyDeeperDomainReductions()

void applyDeeperDomainReductions ( SCIP * scip, SCIP_SOL * baselpsol, int maxstoredomreds, DOMAINREDUCTIONS * targetdomreds, DOMAINREDUCTIONS * downdomreds, DOMAINREDUCTIONS * updomreds )

static

merges the domain reduction data from the two given branching children data into the target parent data

Parameters

scip	SCIP data structure
baselpsol	The LP solution of the base problem. Used to check whether the domain reduction is violated by it.
maxstoredomreds	maximum number of domain reductions to store
targetdomreds	The target that should be filled with the merged data.
downdomreds	One of the source DOMAINREDUCTIONS.
updomreds	The other source DOMAINREDUCTIONS.

Definition at line 2276 of file branch_lookahead.c.

References addLowerBound(), addUpperBound(), assert(), FALSE, i, LABdebugMessage, DOMAINREDUCTIONS::lowerbounds, MAX, MIN, DOMAINREDUCTIONS::nchangedvars, NULL, nvars, DOMAINREDUCTIONS::nviolatedvars, SCIP_Real, SCIP_VERBLEVEL_FULL, SCIPgetNVars(), SCIPgetVars(), DOMAINREDUCTIONS::upperbounds, and vars.

Referenced by selectVarRecursive().

applyDomainReductions()

SCIP_RETCODE applyDomainReductions ( SCIP * scip, CONFIGURATION * config, SCIP_SOL * baselpsol, DOMAINREDUCTIONS * domreds, SCIP_Bool * domredcutoff, SCIP_Bool * domred )

static

Applies the domain reductions to the current node.

Parameters

scip	SCIP data structure
config	the configuration of the branching rule
baselpsol	The LP solution of the base problem. Used to check whether the domain reduction is violated by it.
domreds	The domain reductions that should be applied to the current node.
domredcutoff	pointer to store whether a cutoff was found due to domain reductions
domred	pointer to store whether a domain change was added

Definition at line 2354 of file branch_lookahead.c.

References assert(), FALSE, i, LABdebugMessage, DOMAINREDUCTIONS::lowerbounds, DOMAINREDUCTIONS::nsimplebounds, NULL, CONFIGURATION::onlyvioldomreds, CONFIGURATION::prefersimplebounds, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIP_VERBLEVEL_HIGH, SCIPgetNVars(), SCIPgetSolVal(), SCIPgetVars(), SCIPisGE(), SCIPisGT(), SCIPisLE(), SCIPisLT(), SCIPtightenVarLb(), SCIPtightenVarUb(), SCIPvarGetLbLocal(), SCIPvarGetName(), SCIPvarGetUbLocal(), TRUE, DOMAINREDUCTIONS::upperbounds, and var.

Referenced by selectVarStart().

copyCurrentSolution()

SCIP_RETCODE copyCurrentSolution ( SCIP * scip, SCIP_SOL ** lpsol )

static

Copies the current LP solution into the given pointer. Needs to be freed after usage!

Parameters

scip	SCIP data structure
lpsol	pointer to store the solution into

Definition at line 2529 of file branch_lookahead.c.

References assert(), NULL, SCIP_CALL, SCIP_OKAY, SCIPcreateLPSol(), and SCIPunlinkSol().

Referenced by selectVarStart().

branchOnVar()

SCIP_RETCODE branchOnVar ( SCIP * scip, CONFIGURATION * config, BRANCHINGDECISION * decision )

static

Executes the branching on a given variable with a given value.

Parameters

scip	SCIP data structure
config	config struct with the user configuration
decision	the decision with all the needed data

Definition at line 2548 of file branch_lookahead.c.

References CONFIGURATION::applychildbounds, assert(), BRANCHINGDECISION::boundssize, BRANCHINGDECISION::boundsvalid, BRANCHINGDECISION::branchval, BRANCHINGDECISION::branchvar, BRANCHINGDECISION::downdb, BRANCHINGDECISION::downdbvalid, BRANCHINGDECISION::downlowerbounds, BRANCHINGDECISION::downupperbounds, i, LABdebugMessage, NULL, nvars, SCIP_CALL, SCIP_LONGINT_FORMAT, SCIP_OKAY, SCIP_Real, SCIP_VERBLEVEL_HIGH, SCIPallColsInLP(), SCIPbranchVarVal(), SCIPchgVarLbNode(), SCIPchgVarUbNode(), SCIPdebugMsg, SCIPfeasCeil(), SCIPfeasFloor(), SCIPgetNVars(), SCIPgetSolVal(), SCIPgetVars(), SCIPisExact(), SCIPisGT(), SCIPisIntegral(), SCIPisLT(), SCIPnodeGetEstimate(), SCIPnodeGetLowerbound(), SCIPnodeGetNumber(), SCIPupdateNodeLowerbound(), SCIPvarGetLbLocal(), SCIPvarGetName(), SCIPvarGetUbLocal(), BRANCHINGDECISION::updb, BRANCHINGDECISION::updbvalid, BRANCHINGDECISION::uplowerbounds, BRANCHINGDECISION::upupperbounds, var, and vars.

Referenced by SCIP_DECL_BRANCHEXECLP(), and usePreviousResult().

getNIterationsLastLP()

SCIP_RETCODE getNIterationsLastLP ( SCIP * scip, SCIP_Longint * iterations )

static

Get the number of iterations the last LP needed

Parameters

scip	SCIP data structure
iterations	pointer to store the number of iterations

Definition at line 2682 of file branch_lookahead.c.

References assert(), NULL, SCIP_CALL, SCIP_Longint, SCIP_OKAY, SCIPgetLPI(), and SCIPlpiGetIterations().

Referenced by executeBranching().

executeBranching()

SCIP_RETCODE executeBranching ( SCIP * scip, CONFIGURATION * config, SCIP_Bool downbranching, CANDIDATE * candidate, BRANCHINGRESULTDATA * resultdata, SCIP_SOL * baselpsol, DOMAINREDUCTIONS * domreds, STATUS * status )

static

Creates a new probing node with a new bound for the given candidate and solves the corresponding LP.

Parameters

scip	SCIP data structure
config	configuration to control the behavior
downbranching	the branching direction
candidate	the candidate to branch on
resultdata	pointer to the result data which gets filled with the status
baselpsol	the base lp solution
domreds	struct to store the domain reduction found during propagation
status	status will contain updated lperror and limit fields

Definition at line 2706 of file branch_lookahead.c.

References addLowerBound(), addUpperBound(), assert(), CANDIDATE::branchval, CANDIDATE::branchvar, candidateHasWarmStartInfo(), candidateLoadWarmStartInfo(), BRANCHINGRESULTDATA::cutoff, BRANCHINGRESULTDATA::dualbound, BRANCHINGRESULTDATA::dualboundvalid, FALSE, getNIterationsLastLP(), i, LABdebugMessage, STATUS::limitreached, STATUS::lperror, CONFIGURATION::maxproprounds, BRANCHINGRESULTDATA::niterations, NULL, BRANCHINGRESULTDATA::objval, CONFIGURATION::propagate, SCIP_Bool, SCIP_CALL, SCIP_Longint, SCIP_LONGINT_FORMAT, SCIP_LPSOLSTAT_INFEASIBLE, SCIP_LPSOLSTAT_ITERLIMIT, SCIP_LPSOLSTAT_NOTSOLVED, SCIP_LPSOLSTAT_TIMELIMIT, SCIP_LPSOLSTAT_UNBOUNDEDRAY, SCIP_OKAY, SCIP_Real, SCIP_VERBLEVEL_HIGH, SCIPchgVarLbProbing(), SCIPchgVarUbProbing(), SCIPfeasCeil(), SCIPfeasFloor(), SCIPgetCutoffbound(), SCIPgetLPObjval(), SCIPgetLPSolstat(), SCIPgetNVars(), SCIPgetVars(), SCIPinfinity(), SCIPisFeasGT(), SCIPisFeasIntegral(), SCIPisFeasLT(), SCIPisGE(), SCIPnewProbingNode(), SCIPpropagateProbing(), SCIPsolveProbingLP(), SCIPtryStrongbranchLPSol(), SCIPvarGetLbLocal(), SCIPvarGetName(), SCIPvarGetUbLocal(), TRUE, CONFIGURATION::usedomainreduction, and var.

Referenced by executeBranchingRecursive().

createBinaryConstraint()

SCIP_RETCODE createBinaryConstraint ( SCIP * scip, CONFIGURATION * config, SCIP_CONS ** constraint, char * constraintname, SCIP_VAR ** consvars, int nconsvars )

static

Creates a logic or constraint based on the given 'consvars'. This array has to consist of the negated versions of the variables present on a cutoff "path" (path means all variables from the root directly to the cutoff node). Let x_1, ..., x_n be the variables on a path to a cutoff with the branchings x_i <= 1 for all i. Summed up the constraints would look like x_1 + ... x_n <= n-1. Let y_i = 1 - x_i. Then we have y_1 + ... + y_n >= 1 which is a logic or constraint.

Parameters

scip	SCIP data structure
config	configuration containing flags changing the behavior
constraint	pointer to store the created constraint in
constraintname	name of the new constraint
consvars	array containing the negated binary vars
nconsvars	the number of elements in 'consvars'

Definition at line 2906 of file branch_lookahead.c.

References CONFIGURATION::addbinconsrow, assert(), FALSE, NULL, propagate, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIPcreateConsLogicor(), separate(), and TRUE.

Referenced by applyBinaryConstraints().

createBinaryConstraintName()

void createBinaryConstraintName ( SCIP_VAR ** binaryvars, int nbinaryvars, char * constraintname )

static

Create a name for the binary constraint.

Parameters

binaryvars	the variables contained in the constraint
nbinaryvars	the number of elements in 'binaryvars'
constraintname	the char pointer to store the name in

Definition at line 2949 of file branch_lookahead.c.

References assert(), i, NULL, SCIP_MAXSTRLEN, SCIPsnprintf(), SCIPvarGetName(), and var.

Referenced by applyBinaryConstraints().

addBinaryConstraint()

SCIP_RETCODE addBinaryConstraint ( SCIP * scip, CONFIGURATION * config, BINCONSDATA * binconsdata, SCIP_SOL * baselpsol )

static

Add the constraints found during the lookahead branching. The implicit binary bounds were found when two or more consecutive branchings of binary variables were cutoff. Then these branching constraints can be combined into a single 'binary constraint'.

Parameters

scip	SCIP data structure
config	the configuration of the branching rule
binconsdata	collected binary constraints
baselpsol	the original lp solution, used to check the violation of the constraint

Definition at line 2982 of file branch_lookahead.c.

References CONFIGURATION::addnonviocons, assert(), BINARYVARLIST::binaryvars, BINCONSDATA::binaryvars, BINCONSDATA::conslist, constraintListAppend(), i, LABdebugMessage, BINARYVARLIST::nbinaryvars, NULL, CONSTRAINTLIST::nviolatedcons, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIP_VERBLEVEL_HIGH, SCIPallocBufferArray, SCIPfreeBufferArray, SCIPgetNegatedVar(), SCIPgetSolVal(), SCIPvarIsBinary(), and var.

Referenced by executeBranchingRecursive().

applyBinaryConstraints()

SCIP_RETCODE applyBinaryConstraints ( SCIP * scip, SCIP_NODE * basenode, CONSTRAINTLIST * conslist, CONFIGURATION * config, SCIP_Bool * consadded, SCIP_Bool * cutoff, SCIP_Bool * boundchange )

static

applies the binary constraints to the original problem.

Parameters

scip	SCIP data structure
basenode	original branching node
conslist	list of constraints to be added
config	the configuration of the branching rule
consadded	pointer to store whether at least one constraint was added
cutoff	pointer to store whether the original problem was made infeasible
boundchange	pointer to store whether a bound change has been applied by adding the constraint as a clique

Definition at line 3052 of file branch_lookahead.c.

References CONFIGURATION::addclique, assert(), CONSTRAINTLIST::consvars, createBinaryConstraint(), createBinaryConstraintName(), cutoff, FALSE, i, LABdebugMessage, CONSTRAINTLIST::nconsvars, CONSTRAINTLIST::nelements, NULL, nvars, SCIP_Bool, SCIP_CALL, SCIP_MAXSTRLEN, SCIP_OKAY, SCIP_VERBLEVEL_HIGH, SCIPaddClique(), SCIPaddConsNode(), SCIPallocClearBufferArray, SCIPfreeBufferArray, SCIPgetNNodes(), SCIPinfoMessage(), SCIPprintCons(), SCIPreleaseCons(), SCIPvarGetLbLocal(), SCIPvarIsBinary(), TRUE, vars, and CONSTRAINTLIST::violated.

Referenced by selectVarStart().

areBoundsChanged()

SCIP_Bool areBoundsChanged ( SCIP * scip, SCIP_VAR * var, SCIP_Real lowerbound, SCIP_Real upperbound )

static

checks whether the given bounds are still the bounds of the given variable

Parameters

scip	SCIP data structure
var	variable to check the bounds of
lowerbound	reference lower bound
upperbound	reference upper bound

Definition at line 3181 of file branch_lookahead.c.

References assert(), NULL, SCIP_Bool, SCIP_Real, SCIPisEQ(), SCIPisFeasIntegral(), SCIPvarGetLbLocal(), SCIPvarGetUbLocal(), SCIPvarIsIntegral(), and var.

Referenced by selectVarRecursive().

isBranchFurther()

SCIP_Bool isBranchFurther ( STATUS * status, SCIP_Bool checkdomreds )

static

Checks whether the branching rule should continue or terminate with the currently gathered data

Parameters

status	current status
checkdomreds	should domain reductions be checked?

Definition at line 3201 of file branch_lookahead.c.

References assert(), STATUS::cutoff, STATUS::domred, STATUS::limitreached, STATUS::lperror, STATUS::maxnconsreached, NULL, and SCIP_Bool.

Referenced by executeBranchingRecursive(), filterCandidates(), isBranchFurtherLoopDecrement(), and selectVarStart().

isBranchFurtherLoopDecrement()

SCIP_Bool isBranchFurtherLoopDecrement ( STATUS * status, int * loopcounter )

static

Checks whether the branching rule should continue or terminate with the currently gathered data. Additionally decrements the given loopcounter. This is needed to better emulate the behavior of FSB by LAB with a depth of 1.

Parameters

status	current status
loopcounter	the counter to decrement

Definition at line 3215 of file branch_lookahead.c.

References assert(), FALSE, isBranchFurther(), NULL, and SCIP_Bool.

Referenced by selectVarRecursive().

isUseOldBranching()

SCIP_Bool isUseOldBranching ( SCIP * scip, PERSISTENTDATA * persistent, CONFIGURATION * config, SCIP_VAR * branchvar )

static

determines whether the previous LAB result of a variable should be reused

Parameters

scip	SCIP data structure
persistent	data storage over multiple calls to the rule
config	the configuration of the branching rule
branchvar	variable to check

Definition at line 3235 of file branch_lookahead.c.

References assert(), CONFIGURATION::inscoring, PERSISTENTDATA::lastbranchid, PERSISTENTDATA::lastbranchnlps, NULL, CONFIGURATION::reevalage, CONFIGURATION::reevalagefsb, SCIP_Bool, SCIPgetNLPs(), SCIPgetNNodes(), SCIPgetVarStrongbranchLPAge(), SCIPgetVarStrongbranchNode(), and SCIPvarGetProbindex().

Referenced by selectVarRecursive().

getOldBranching()

SCIP_RETCODE getOldBranching ( SCIP * scip, PERSISTENTDATA * persistent, CONFIGURATION * config, SCIP_VAR * branchvar, BRANCHINGRESULTDATA * downbranchingresult, BRANCHINGRESULTDATA * upbranchingresult, SCIP_Real * oldlpobjval )

static

retrieves previous LAB result for the given variable

Parameters

scip	SCIP data structure
persistent	data storage over multiple calls to the rule
config	the configuration of the branching rule
branchvar	variable to get previous results for
downbranchingresult	pointer to store the previous down result in
upbranchingresult	pointer to store the previous up result in
oldlpobjval	pointer to store the previous base lp objval in

Definition at line 3261 of file branch_lookahead.c.

References assert(), branchingResultDataCopy(), BRANCHINGRESULTDATA::dualbound, BRANCHINGRESULTDATA::dualboundvalid, CONFIGURATION::inscoring, LABdebugMessage, PERSISTENTDATA::lastbranchdownres, PERSISTENTDATA::lastbranchlpobjval, PERSISTENTDATA::lastbranchnlps, PERSISTENTDATA::lastbranchupres, MAX, NULL, BRANCHINGRESULTDATA::objval, SCIP_CALL, SCIP_LONGINT_FORMAT, SCIP_OKAY, SCIP_Real, SCIP_VERBLEVEL_HIGH, SCIPgetNLPs(), SCIPgetVarStrongbranchLast(), SCIPvarGetName(), and SCIPvarGetProbindex().

Referenced by selectVarRecursive().

updateOldBranching()

SCIP_RETCODE updateOldBranching ( SCIP * scip, PERSISTENTDATA * persistent, CONFIGURATION * config, SCIP_VAR * branchvar, SCIP_Real branchval, BRANCHINGRESULTDATA * downbranchingresult, BRANCHINGRESULTDATA * upbranchingresult, SCIP_Real lpobjval )

static

stores the LAB result for use in a later call to the branching rule

Parameters

scip	SCIP data structure
persistent	data storage over multiple calls to the rule
config	the configuration of the branching rule
branchvar	variable to store previous results for
branchval	the value of branchvar
downbranchingresult	down branching result to store
upbranchingresult	up branching result to store
lpobjval	base lp obj val

Definition at line 3314 of file branch_lookahead.c.

References assert(), branchingResultDataCopy(), BRANCHINGRESULTDATA::dualbound, BRANCHINGRESULTDATA::dualboundvalid, CONFIGURATION::inscoring, PERSISTENTDATA::lastbranchdownres, PERSISTENTDATA::lastbranchid, PERSISTENTDATA::lastbranchlpobjval, PERSISTENTDATA::lastbranchnlps, PERSISTENTDATA::lastbranchupres, BRANCHINGRESULTDATA::niterations, NULL, SCIP_CALL, SCIP_Longint, SCIP_OKAY, SCIP_Real, SCIPgetNLPs(), SCIPgetNNodes(), SCIPsetVarStrongbranchData(), and SCIPvarGetProbindex().

Referenced by selectVarRecursive().

getFSBResult()

SCIP_RETCODE getFSBResult ( SCIP * scip, STATUS * status, PERSISTENTDATA * persistent, CONFIGURATION * config, SCIP_SOL * baselpsol, DOMAINREDUCTIONS * domainreductions, BINCONSDATA * binconsdata, CANDIDATELIST * candidatelist, BRANCHINGDECISION * decision, SCORECONTAINER * scorecontainer, LEVEL2DATA * level2data, SCIP_Real lpobjval )

static

calculates the FSB scores for the given candidates

Parameters

scip	SCIP data structure
status	current status
persistent	container to store data over multiple calls to the branching rule; or NULL
config	the configuration of the branching rule
baselpsol	base lp solution
domainreductions	container collecting all domain reductions found; or NULL
binconsdata	container collecting all binary constraints; or NULL
candidatelist	list containing all candidates to consider
decision	struct to store the final decision
scorecontainer	container to retrieve already calculated scores; or NULL
level2data	level 2 LP results data
lpobjval	base LP objective value

Definition at line 3355 of file branch_lookahead.c.

References assert(), FALSE, CONFIGURATION::inscoring, NULL, CONFIGURATION::recursiondepth, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPgetProbingDepth(), SCIPinProbing(), selectVarRecursive(), and TRUE.

Referenced by ensureScoresPresent().

calculateScoreFromResult()

SCIP_Real calculateScoreFromResult ( SCIP * scip, SCIP_VAR * branchvar, BRANCHINGRESULTDATA * downbranchingresult, BRANCHINGRESULTDATA * upbranchingresult, SCIP_Real lpobjval )

static

calculates the score based on the down and up branching result

Parameters

scip	SCIP data structure
branchvar	variable to get the score for
downbranchingresult	branching result of the down branch
upbranchingresult	branching result of the up branch
lpobjval	objective value to get difference to as gain

Definition at line 3440 of file branch_lookahead.c.

References assert(), BRANCHINGRESULTDATA::cutoff, BRANCHINGRESULTDATA::dualbound, MAX, NULL, SCIP_Real, SCIPgetBranchScore(), and SCIPsumepsilon().

Referenced by calculateScore().

calculateScoreFromResult2()

SCIP_Real calculateScoreFromResult2 ( SCIP * scip, SCIP_VAR * branchvar, BRANCHINGRESULTDATA * downbranchingresult, BRANCHINGRESULTDATA * upbranchingresult, SCIP_Real lpobjval )

static

calculates the score based on the down and up branching result

Parameters

scip	SCIP data structure
branchvar	variable to get the score for
downbranchingresult	branching result of the down branch
upbranchingresult	branching result of the up branch
lpobjval	objective value to get difference to as gain

Definition at line 3484 of file branch_lookahead.c.

References assert(), BRANCHINGRESULTDATA::cutoff, BRANCHINGRESULTDATA::dualbound, MAX, NULL, BRANCHINGRESULTDATA::objval, SCIP_Real, SCIPgetBranchScore(), and SCIPsumepsilon().

Referenced by calculateScore().

calculateScoreFromDeeperscore()

SCIP_Real calculateScoreFromDeeperscore ( SCIP * scip, SCIP_VAR * branchvar, BRANCHINGRESULTDATA * downbranchingresult, BRANCHINGRESULTDATA * upbranchingresult )

static

calculates the score based on the down and up branching scores

Parameters

scip	SCIP data structure
branchvar	variable to get the score for
downbranchingresult	branching result of the down branch
upbranchingresult	branching result of the up branch

Definition at line 3554 of file branch_lookahead.c.

References assert(), BRANCHINGRESULTDATA::cutoff, BRANCHINGRESULTDATA::deeperscore, MAX, NULL, SCIP_Real, SCIPgetBranchScore(), SCIPisStopped(), and SCIPsumepsilon().

Referenced by calculateScore().

calculateScoreFromDeeperscoreAndCutoffs()

SCIP_Real calculateScoreFromDeeperscoreAndCutoffs ( SCIP * scip, SCIP_VAR * branchvar, BRANCHINGRESULTDATA * downbranchingresult, BRANCHINGRESULTDATA * upbranchingresult )

static

calculates the score based on the down and up branching scores

Parameters

scip	SCIP data structure
branchvar	variable to get the score for
downbranchingresult	branching result of the down branch
upbranchingresult	branching result of the up branch

Definition at line 3591 of file branch_lookahead.c.

References assert(), BRANCHINGRESULTDATA::cutoff, BRANCHINGRESULTDATA::deeperscore, MAX, BRANCHINGRESULTDATA::ndeepestcutoffs, BRANCHINGRESULTDATA::ndeepestnodes, BRANCHINGRESULTDATA::ntotalgains, NULL, SCIP_Real, SCIPgetBranchScore(), SCIPisStopped(), SCIPsumepsilon(), and BRANCHINGRESULTDATA::totalgains.

Referenced by calculateScore().

calculateWeightedGain()

SCIP_Real calculateWeightedGain ( SCIP * scip, CONFIGURATION * config, BRANCHINGRESULTDATA * downbranchingresult, BRANCHINGRESULTDATA * upbranchingresult, SCIP_Real lpobjval )

static

calculates the combined gain, weighted with parameters given by the user configuration

Parameters

scip	SCIP data structure
config	LAB configuration
downbranchingresult	branching result of the down branch
upbranchingresult	branching result of the up branch
lpobjval	objective value to get difference to as gain

Definition at line 3647 of file branch_lookahead.c.

References assert(), BRANCHINGRESULTDATA::cutoff, BRANCHINGRESULTDATA::dualbound, MAX, MIN, CONFIGURATION::minweight, NULL, SCIP_Real, SCIPinfinity(), and CONFIGURATION::scoringfunction.

Referenced by calculateScore().

calculateScaledCutoffScore()

SCIP_Real calculateScaledCutoffScore ( BRANCHINGRESULTDATA * downbranchingresult, BRANCHINGRESULTDATA * upbranchingresult )

static

calculates the score as mentioned in the lookahead branching paper by Glankwamdee and Linderoth; their score scales the number of cutoffs on the last layer of a 2-level temporary branching tree with the average gain of every last level problem; together with the best gain for each branch of a variable we get the final score

Parameters

downbranchingresult	branching result of the down branch
upbranchingresult	branching result of the up branch

Definition at line 3697 of file branch_lookahead.c.

References assert(), BRANCHINGRESULTDATA::bestgain, MAX, BRANCHINGRESULTDATA::ndeepestcutoffs, BRANCHINGRESULTDATA::ntotalgains, NULL, SCIP_Real, and BRANCHINGRESULTDATA::totalgains.

Referenced by calculateScore().

calculateWeightedCutoffScore()

SCIP_Real calculateWeightedCutoffScore ( CONFIGURATION * config, BRANCHINGRESULTDATA * downbranchingresult, BRANCHINGRESULTDATA * upbranchingresult )

static

calculates the score as mentioned in the lookahead branching paper by Glankwamdee and Linderoth; their score scales the number of cutoffs on the last layer of a 2-level temporary branching tree with the average gain of every last level problem; together with the best gain for each branch of a variable we get the final score

Parameters

config	LAB configuration
downbranchingresult	branching result of the down branch
upbranchingresult	branching result of the up branch

Definition at line 3729 of file branch_lookahead.c.

References assert(), BRANCHINGRESULTDATA::bestgain, MAX, MIN, CONFIGURATION::minweight, BRANCHINGRESULTDATA::ndeepestcutoffs, BRANCHINGRESULTDATA::ndeepestnodes, BRANCHINGRESULTDATA::ntotalgains, NULL, SCIP_Real, and BRANCHINGRESULTDATA::totalgains.

Referenced by calculateScore().

calculateCutoffScore()

SCIP_Real calculateCutoffScore ( SCIP * scip, SCIP_VAR * branchvar, BRANCHINGRESULTDATA * downbranchingresult, BRANCHINGRESULTDATA * upbranchingresult, SCIP_Real lpobjval )

static

Parameters

scip	SCIP data structure
branchvar	variable to get the score for
downbranchingresult	branching result of the down branch
upbranchingresult	branching result of the up branch
lpobjval	objective value to get difference to as gain

Definition at line 3758 of file branch_lookahead.c.

References assert(), BRANCHINGRESULTDATA::cutoff, BRANCHINGRESULTDATA::dualbound, MAX, BRANCHINGRESULTDATA::ndeepestcutoffs, NULL, SCIP_Real, SCIPgetBranchScore(), SCIPgetCutoffbound(), SCIPgetNPseudoBranchCands(), and SCIPsumepsilon().

Referenced by calculateScore().

calculateRelCutoffScore()

SCIP_Real calculateRelCutoffScore ( SCIP * scip, SCIP_VAR * branchvar, BRANCHINGRESULTDATA * downbranchingresult, BRANCHINGRESULTDATA * upbranchingresult, SCIP_Real lpobjval )

static

Parameters

scip	SCIP data structure
branchvar	variable to get the score for
downbranchingresult	branching result of the down branch
upbranchingresult	branching result of the up branch
lpobjval	objective value to get difference to as gain

Definition at line 3817 of file branch_lookahead.c.

References assert(), BRANCHINGRESULTDATA::cutoff, BRANCHINGRESULTDATA::dualbound, MAX, BRANCHINGRESULTDATA::ndeepestcutoffs, BRANCHINGRESULTDATA::ndeepestnodes, NULL, SCIP_Real, SCIPgetBranchScore(), SCIPgetCutoffbound(), SCIPgetNLPRows(), SCIPgetNPseudoBranchCands(), and SCIPsumepsilon().

Referenced by calculateScore().

calculateScore()

SCIP_Real calculateScore ( SCIP * scip, CONFIGURATION * config, SCIP_VAR * branchvar, BRANCHINGRESULTDATA * downbranchingresult, BRANCHINGRESULTDATA * upbranchingresult, SCIP_Real lpobjval, SCIP_Real baselpobjval )

static

scoring method that selects an actual scoring method based on the user configuration

Parameters

scip	SCIP data structure
config	LAB configuration
branchvar	variable to get the score for
downbranchingresult	branching result of the down branch
upbranchingresult	branching result of the up branch
lpobjval	objective value to get difference to as gain
baselpobjval	base objective value to get difference to as gain

Definition at line 3881 of file branch_lookahead.c.

References assert(), calculateCutoffScore(), calculateRelCutoffScore(), calculateScaledCutoffScore(), calculateScoreFromDeeperscore(), calculateScoreFromDeeperscoreAndCutoffs(), calculateScoreFromResult(), calculateScoreFromResult2(), calculateWeightedCutoffScore(), calculateWeightedGain(), CONFIGURATION::deeperscoringfunction, CONFIGURATION::inscoring, NULL, SCIP_Real, SCIPgetProbingDepth(), CONFIGURATION::scoringfunction, and CONFIGURATION::scoringscoringfunction.

Referenced by selectVarRecursive().

calculateScoreFromPseudocosts()

SCIP_Real calculateScoreFromPseudocosts ( SCIP * scip, CANDIDATE * lpcand )

static

calculates the score based on the pseudocosts of the given variable

Parameters

scip	SCIP data structure
lpcand	candidate to get the score for

Definition at line 3946 of file branch_lookahead.c.

References assert(), CANDIDATE::branchvar, CANDIDATE::fracval, NULL, SCIP_Real, SCIPgetBranchScore(), and SCIPgetVarPseudocostVal().

Referenced by ensureScoresPresent().

sortFirstCandidatesByScore()

void sortFirstCandidatesByScore ( SCIP * scip, CANDIDATELIST * candidatelist, SCORECONTAINER * scorecontainer, int nbestcandidates )

static

sorts the best candidates (w.r.t. the score in the container) of the candidate list to the front of the list

Parameters

scip	SCIP data structure
candidatelist	candidates to be sorted
scorecontainer	container with the scores for each candidate
nbestcandidates	number of candidates that should be kept sorted at the start of the list

Definition at line 3995 of file branch_lookahead.c.

References assert(), CANDIDATE::branchvar, CANDIDATELIST::candidates, findInsertionPoint(), i, LABdebugMessage, MIN, CANDIDATELIST::ncandidates, NULL, SCIP_Real, SCIP_VERBLEVEL_HIGH, SCIPvarGetProbindex(), and SCORECONTAINER::scores.

Referenced by filterCandidates().

isCandidateReliable()

SCIP_Bool isCandidateReliable ( SCIP * scip, SCIP_VAR * branchvar )

static

checks whether the given candidates is reliable, so that its pseudocosts may be used

Parameters

scip	SCIP data structure
branchvar	var to check for reliability

Definition at line 4060 of file branch_lookahead.c.

References assert(), MIN, NULL, SCIP_Bool, SCIP_BRANCHDIR_DOWNWARDS, SCIP_BRANCHDIR_UPWARDS, SCIP_Real, and SCIPgetVarPseudocostCountCurrentRun().

Referenced by ensureScoresPresent().

isCurrentNodeCutoff()

SCIP_Bool isCurrentNodeCutoff ( SCIP * scip )

static

checks whether the current problem is feasible or cutoff

Parameters

scip	SCIP data structure

Definition at line 4082 of file branch_lookahead.c.

References assert(), NULL, SCIP_Bool, SCIPgetCutoffdepth(), and SCIPgetDepth().

Referenced by filterCandidates().

ensureScoresPresent()

SCIP_RETCODE ensureScoresPresent ( SCIP * scip, STATUS * status, PERSISTENTDATA * persistent, CONFIGURATION * config, SCIP_SOL * baselpsol, DOMAINREDUCTIONS * domainreductions, BINCONSDATA * binconsdata, CANDIDATELIST * allcandidates, BRANCHINGDECISION * decision, SCORECONTAINER * scorecontainer, LEVEL2DATA * level2data, SCIP_Real lpobjval )

static

Ensures that the scores are present in the scorecontainer for each of the candidates to consider

Parameters

scip	SCIP data structure
status	current status
persistent	container to store data over multiple calls to the branching rule; or NULL
config	the configuration of the branching rule
baselpsol	base lp solution
domainreductions	container collecting all domain reductions found; or NULL
binconsdata	container collecting all binary constraints; or NULL
allcandidates	list containing all candidates to consider
decision	struct to store the final decision
scorecontainer	container to retrieve already calculated scores; or NULL
level2data	level 2 LP results data
lpobjval	base LP objective value

Definition at line 4093 of file branch_lookahead.c.

References CONFIGURATION::abbrevpseudo, assert(), CANDIDATE::branchvar, calculateScoreFromPseudocosts(), candidateListCreate(), candidateListFree(), CANDIDATELIST::candidates, getFSBResult(), i, isCandidateReliable(), LABdebugMessage, CONFIGURATION::level2avgscore, CONFIGURATION::level2zeroscore, CANDIDATELIST::ncandidates, SCORECONTAINER::nsetscores, NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIP_VERBLEVEL_HIGH, SCIPallocBufferArray, SCIPfreeBufferArray, SCIPgetProbingDepth(), SCIPisLT(), SCIPvarGetProbindex(), scoreContainerSetScore(), scoreContainterResetBestSortedCands(), SCORECONTAINER::scores, and SCORECONTAINER::scoresum.

Referenced by filterCandidates().

filterCandidates()

SCIP_RETCODE filterCandidates ( SCIP * scip, STATUS * status, PERSISTENTDATA * persistent, CONFIGURATION * config, SCIP_SOL * baselpsol, DOMAINREDUCTIONS * domainreductions, BINCONSDATA * binconsdata, CANDIDATELIST * candidatelist, BRANCHINGDECISION * decision, SCORECONTAINER * scorecontainer, LEVEL2DATA * level2data, SCIP_Real lpobjval )

static

Get the candidates to temporarily branch on. In the LAB case this is the complete list of possible candidates. In the ALAB case only the 'best' candidates are returned.

Parameters

scip	SCIP data structure
status	current status
persistent	container to store data over multiple calls to the branching rule; or NULL
config	the configuration of the branching rule
baselpsol	base lp solution
domainreductions	container collecting all domain reductions found; or NULL
binconsdata	container collecting all binary constraints; or NULL
candidatelist	list of candidates to branch on
decision	struct to store the final decision
scorecontainer	container to retrieve already calculated scores; or NULL
level2data	level 2 LP results data
lpobjval	base LP objective value

Definition at line 4225 of file branch_lookahead.c.

References CONFIGURATION::abbreviated, assert(), CANDIDATE::branchvar, candidateListKeep(), CANDIDATELIST::candidates, STATUS::cutoff, SCORECONTAINER::downgains, ensureScoresPresent(), CONFIGURATION::filterbymaxgain, i, isBranchFurther(), isCurrentNodeCutoff(), LABdebugMessage, MAX, CONFIGURATION::maxncands, CONFIGURATION::maxndeepercands, MIN, CANDIDATELIST::ncandidates, NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIP_VERBLEVEL_HIGH, SCIPgetProbingDepth(), SCIPinProbing(), SCIPisSumLE(), SCIPvarGetName(), SCIPvarGetProbindex(), SCORECONTAINER::scores, sortFirstCandidatesByScore(), TRUE, SCORECONTAINER::upgains, and CONFIGURATION::worsefactor.

Referenced by executeBranchingRecursive(), and selectVarStart().

executeBranchingRecursive()

SCIP_RETCODE executeBranchingRecursive ( SCIP * scip, STATUS * status, CONFIGURATION * config, SCIP_SOL * baselpsol, CANDIDATE * candidate, SCIP_Real localbaselpsolval, SCIP_Real baselpobjval, int recursiondepth, DOMAINREDUCTIONS * domainreductions, BINCONSDATA * binconsdata, LEVEL2DATA * level2data, BRANCHINGRESULTDATA * branchingresult, SCORECONTAINER * scorecontainer, SCIP_Bool downbranching )

static

Executes the general branching on a variable in a given direction (up/down) and repeats the algorithm from the new node

Parameters

scip	SCIP data structure
status	current status
config	the configuration of the branching rule
baselpsol	the base lp solution
candidate	candidate to branch on
localbaselpsolval	the objective value of the current temporary problem
baselpobjval	LP objective value of focus node (not probing)
recursiondepth	remaining recursion depth
domainreductions	container collecting all domain reductions found; or NULL
binconsdata	container collecting all binary constraints; or NULL
level2data	level 2 LP results data
branchingresult	container to store the result of the branching in
scorecontainer	container to retrieve already calculated scores; or NULL
downbranching	should we branch up or down in here?

Definition at line 4361 of file branch_lookahead.c.

References addBinaryConstraint(), assert(), BRANCHINGRESULTDATA::bestgain, binaryVarListAppend(), binaryVarListDrop(), BINCONSDATA::binaryvars, LEVEL2DATA::branchdir1, LEVEL2DATA::branchdir2, branchingDecisionCreate(), branchingDecisionFree(), CANDIDATE::branchval, LEVEL2DATA::branchval1, LEVEL2DATA::branchval2, CANDIDATE::branchvar, LEVEL2DATA::branchvar1, LEVEL2DATA::branchvar2, candidateListFree(), candidateListGetAllFractionalCandidates(), candidateStoreWarmStartInfo(), BRANCHINGRESULTDATA::cutoff, STATUS::cutoff, BRANCHINGRESULTDATA::deeperscore, STATUS::domred, BRANCHINGRESULTDATA::dualbound, BRANCHINGRESULTDATA::dualboundvalid, executeBranching(), FALSE, filterCandidates(), CANDIDATE::fracval, CONFIGURATION::inscoring, isBranchFurther(), LABdebugMessage, level2dataGetResult(), level2dataStoreResult(), STATUS::limitreached, STATUS::lperror, MAX, BINARYVARLIST::nbinaryvars, CANDIDATELIST::ncandidates, BRANCHINGRESULTDATA::ndeepestcutoffs, BRANCHINGRESULTDATA::ndeepestnodes, BRANCHINGRESULTDATA::niterations, BRANCHINGRESULTDATA::ntotalgains, NULL, BRANCHINGRESULTDATA::objval, BRANCHINGDECISION::proveddb, result, CONFIGURATION::reusebasis, SCIP_Bool, SCIP_CALL, SCIP_LONGINT_FORMAT, SCIP_OKAY, SCIP_Real, SCIP_VERBLEVEL_HIGH, SCIPallColsInLP(), SCIPbacktrackProbing(), SCIPfeasCeil(), SCIPfeasFloor(), SCIPgetCutoffbound(), SCIPgetLPSolstat(), SCIPgetNegatedVar(), SCIPgetProbingDepth(), SCIPisGE(), SCIPisStopped(), SCIPupdateVarPseudocost(), SCIPvarGetLbLocal(), SCIPvarGetName(), SCIPvarGetProbindex(), SCIPvarGetUbLocal(), SCIPvarIsBinary(), BRANCHINGDECISION::score, selectVarRecursive(), statusCreate(), statusFree(), BRANCHINGRESULTDATA::totalgains, and TRUE.

Referenced by selectVarRecursive().

isStoreDecision()

SCIP_Bool isStoreDecision ( CONFIGURATION * config, BINCONSDATA * binconsdata, DOMAINREDUCTIONS * domainreductions )

static

checks whether the current decision should be stored. This is the case if we found domain reductions or constraints that will be applied, but none of them cuts off the current LP solution. Then our current decision still holds true for the next call and can be reused without further calculations

Parameters

config	the configuration of the branching rule
binconsdata	container collecting all binary constraints; or NULL
domainreductions	container collecting all domain reductions found; or NULL

Definition at line 5293 of file branch_lookahead.c.

References assert(), BINCONSDATA::conslist, FALSE, DOMAINREDUCTIONS::nchangedvars, CONSTRAINTLIST::nelements, NULL, CONSTRAINTLIST::nviolatedcons, DOMAINREDUCTIONS::nviolatedvars, SCIP_Bool, and CONFIGURATION::storeunviolatedsol.

Referenced by selectVarStart().

selectVarStart()

SCIP_RETCODE selectVarStart ( SCIP * scip, CONFIGURATION * config, PERSISTENTDATA * persistent, STATUS * status, BRANCHINGDECISION * decision, SCORECONTAINER * scorecontainer, CANDIDATELIST * candidatelist )

static

starting point to obtain a branching decision via LAB/ALAB.

Parameters

scip	SCIP data structure
config	the configuration of the branching rule
persistent	container to store data over multiple calls to the branching rule; or NULL
status	current status
decision	struct to store the final decision
scorecontainer	container to retrieve already calculated scores; or NULL
candidatelist	list of candidates to branch on

Definition at line 5319 of file branch_lookahead.c.

References CONFIGURATION::abbreviated, STATUS::addedbinconss, applyBinaryConstraints(), applyDomainReductions(), assert(), BINCONSDATA::binaryvars, binConsDataCreate(), binConsDataFree(), branchingDecisionCopy(), branchingDecisionIsValid(), BRANCHINGDECISION::branchval, CANDIDATE::branchval, BRANCHINGDECISION::branchvar, CANDIDATE::branchvar, CANDIDATELIST::candidates, BINCONSDATA::conslist, copyCurrentSolution(), STATUS::cutoff, STATUS::depthtoosmall, domainReductionsCreate(), domainReductionsFree(), STATUS::domred, STATUS::domredcutoff, BRANCHINGDECISION::downdb, BRANCHINGDECISION::downdbvalid, FALSE, filterCandidates(), CONFIGURATION::inscoring, isBranchFurther(), isStoreDecision(), LABdebugMessage, level2dataCreate(), level2dataFree(), STATUS::lperror, STATUS::maxnconsreached, BINARYVARLIST::nbinaryvars, CANDIDATELIST::ncandidates, CONSTRAINTLIST::nelements, NULL, PERSISTENTDATA::olddecision, PERSISTENTDATA::oldnnodelpiterations, PERSISTENTDATA::oldnnodelps, PERSISTENTDATA::oldntotalnodes, BRANCHINGDECISION::proveddb, CONFIGURATION::recursiondepth, SCIP_Bool, SCIP_CALL, SCIP_MAXTREEDEPTH, SCIP_OKAY, SCIP_Real, SCIP_VERBLEVEL_FULL, SCIP_VERBLEVEL_HIGH, SCIPABORT, SCIPceil(), SCIPenableVarHistory(), SCIPendStrongbranch(), SCIPfreeSol(), SCIPgetCurrentNode(), SCIPgetDepth(), SCIPgetLPObjval(), SCIPgetNNodeLPIterations(), SCIPgetNNodeLPs(), SCIPgetNNodeZeroIterationLPs(), SCIPgetNTotalNodes(), SCIPgetProbingDepth(), SCIPgetSolVal(), SCIPinProbing(), SCIPnodeGetNumber(), SCIPstartStrongbranch(), SCIPstatistic, SCIPvarGetLbLocal(), SCIPvarGetName(), SCIPvarGetProbindex(), SCIPvarGetUbLocal(), SCORECONTAINER::scores, selectVarRecursive(), TRUE, BRANCHINGDECISION::updb, BRANCHINGDECISION::updbvalid, CONFIGURATION::usebincons, CONFIGURATION::usedomainreduction, and CONFIGURATION::uselevel2data.

Referenced by SCIP_DECL_BRANCHEXECLP().

isUsePreviousResult()

SCIP_Bool isUsePreviousResult ( SCIP * scip, SCIP_BRANCHRULEDATA * branchruledata )

static

We can use the previous result, stored in the branchruledata, if the branchingvariable (as an indicator) is set and the current lp solution is equal to the previous lp solution.

Returns

TRUE, if we can branch on the previous decision, FALSE, else.

Parameters

scip	SCIP data structure
branchruledata	branching rule data

Definition at line 5654 of file branch_lookahead.c.

References assert(), branchingDecisionIsValid(), LABdebugMessage, NULL, PERSISTENTDATA::olddecision, PERSISTENTDATA::oldnnodelpiterations, PERSISTENTDATA::oldnnodelps, PERSISTENTDATA::oldntotalnodes, SCIP_Bool, SCIP_VERBLEVEL_HIGH, SCIPgetNNodeLPIterations(), SCIPgetNNodeLPs(), SCIPgetNNodeZeroIterationLPs(), and SCIPgetNTotalNodes().

Referenced by SCIP_DECL_BRANCHEXECLP().

usePreviousResult()

SCIP_RETCODE usePreviousResult ( SCIP * scip, SCIP_BRANCHRULEDATA * branchruledata, SCIP_RESULT * result )

static

Uses the results from the previous run saved in the branchruledata to branch. This is the case, if in the previous run only non-violating constraints were added. In that case we can use the branching decision we would have made then. If everything worked, the result pointer contains SCIP_BRANCHED.

Returns

SCIP_OKAY is returned if everything worked. Otherwise a suitable error code is passed. See SCIP_RETCODE for a complete list of error codes.

Parameters

scip	SCIP data structure
branchruledata	branching rule data
result	the pointer to the branching result

Definition at line 5690 of file branch_lookahead.c.

References assert(), branchOnVar(), LABdebugMessage, NULL, result, SCIP_BRANCHED, SCIP_CALL, SCIP_OKAY, SCIP_VERBLEVEL_FULL, SCIP_VERBLEVEL_HIGH, and SCIPvarGetName().

Referenced by SCIP_DECL_BRANCHEXECLP().

freePersistent()

SCIP_RETCODE freePersistent ( SCIP * scip, SCIP_BRANCHRULEDATA * branchruledata )

static

free persistent data structure

Parameters

scip	SCIP data structure
branchruledata	branching rule data

Definition at line 5720 of file branch_lookahead.c.

References assert(), FALSE, i, PERSISTENTDATA::lastbranchdownres, PERSISTENTDATA::lastbranchid, PERSISTENTDATA::lastbranchlpobjval, PERSISTENTDATA::lastbranchnlps, PERSISTENTDATA::lastbranchupres, NULL, nvars, PERSISTENTDATA::nvars, SCIP_OKAY, SCIPfreeBlockMemory, and SCIPfreeBlockMemoryArray.

Referenced by initBranchruleData(), and SCIP_DECL_BRANCHEXITSOL().

initBranchruleData()

SCIP_RETCODE initBranchruleData ( SCIP * scip, SCIP_BRANCHRULEDATA * branchruledata )

static

initializes the branchruledata and the contained structs

Parameters

scip	SCIP data structure
branchruledata	the branch rule data to initialize

Definition at line 5767 of file branch_lookahead.c.

References assert(), branchingDecisionInit(), freePersistent(), i, LABdebugMessage, NULL, nvars, SCIP_CALL, SCIP_OKAY, SCIP_VERBLEVEL_FULL, SCIPallocBlockMemory, SCIPallocBlockMemoryArray, SCIPgetNContImplVars(), SCIPgetNContVars(), SCIPgetNVars(), and TRUE.

Referenced by SCIP_DECL_BRANCHEXECLP().

SCIP_DECL_BRANCHCOPY()

SCIP_DECL_BRANCHCOPY ( branchCopyLookahead )

static

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

Definition at line 5827 of file branch_lookahead.c.

References assert(), BRANCHRULE_NAME, NULL, SCIP_CALL, SCIP_OKAY, SCIPbranchruleGetName(), and SCIPincludeBranchruleLookahead().

SCIP_DECL_BRANCHFREE()

SCIP_DECL_BRANCHFREE ( branchFreeLookahead )

static

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

Definition at line 5841 of file branch_lookahead.c.

References assert(), NULL, SCIP_OKAY, SCIPbranchruleGetData(), SCIPbranchruleSetData(), and SCIPfreeBlockMemory.

SCIP_DECL_BRANCHINIT()

SCIP_DECL_BRANCHINIT ( branchInitLookahead )

static

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

Definition at line 5860 of file branch_lookahead.c.

References assert(), LABdebugMessage, NULL, SCIP_CALL, SCIP_OKAY, SCIP_VERBLEVEL_FULL, SCIP_VERBLEVEL_HIGH, SCIPallocMemory, SCIPallocMemoryArray, SCIPbranchruleGetData(), SCIPgetNContImplVars(), SCIPgetNContVars(), and SCIPgetNVars().

SCIP_DECL_BRANCHEXIT()

SCIP_DECL_BRANCHEXIT ( branchExitLookahead )

static

deinitialization method of branching rule (called before transformed problem is freed)

Definition at line 5920 of file branch_lookahead.c.

References assert(), NULL, SCIP_OKAY, SCIPbranchruleGetData(), SCIPfreeMemory, and SCIPfreeMemoryArray.

SCIP_DECL_BRANCHEXITSOL()

SCIP_DECL_BRANCHEXITSOL ( branchExitSolLookahead )

static

solving process deinitialization method of branching rule (called before branch and bound process data is freed)

Definition at line 5957 of file branch_lookahead.c.

References assert(), freePersistent(), NULL, SCIP_CALL, SCIP_OKAY, and SCIPbranchruleGetData().

SCIP_DECL_BRANCHEXECLP()

SCIP_DECL_BRANCHEXECLP ( branchExeclpLookahead )

static

branching execution method for fractional LP solutions

Definition at line 5974 of file branch_lookahead.c.

References CONFIGURATION::abbreviated, STATUS::addedbinconss, assert(), branchingDecisionCreate(), branchingDecisionFree(), branchingDecisionIsValid(), branchOnVar(), BRANCHRULE_NAME, BRANCHINGDECISION::branchval, CANDIDATE::branchval, BRANCHINGDECISION::branchvar, CANDIDATE::branchvar, candidateListFree(), candidateListGetAllFractionalCandidates(), CANDIDATELIST::candidates, STATUS::cutoff, STATUS::depthtoosmall, STATUS::domred, STATUS::domredcutoff, BRANCHINGDECISION::downdb, i, initBranchruleData(), isUsePreviousResult(), LABdebugMessage, STATUS::limitreached, STATUS::lperror, STATUS::maxnconsreached, CANDIDATELIST::ncandidates, NULL, BRANCHINGDECISION::proveddb, result, SCIP_Bool, SCIP_BRANCHED, SCIP_CALL, SCIP_CONSADDED, SCIP_CUTOFF, SCIP_OKAY, SCIP_REDUCEDDOM, SCIP_VERBLEVEL_FULL, SCIP_VERBLEVEL_HIGH, SCIP_VERBLEVEL_NORMAL, SCIPallColsInLP(), SCIPbranchruleGetData(), SCIPbranchruleGetName(), SCIPgetCurrentNode(), SCIPisExact(), SCIPisStopped(), SCIPnodeGetNumber(), SCIPupdateLocalLowerbound(), SCIPvarGetName(), scoreContainerCreate(), scoreContainerFree(), selectVarStart(), statusCreate(), statusFree(), CONFIGURATION::storeunviolatedsol, BRANCHINGDECISION::updb, CONFIGURATION::usebincons, and usePreviousResult().

SCIPincludeBranchruleLookahead()

SCIP_RETCODE SCIPincludeBranchruleLookahead

(

SCIP *

scip

)

creates the lookahead branching rule and includes it in SCIP

Parameters

scip	SCIP data structure

Definition at line 6209 of file branch_lookahead.c.

References assert(), BRANCHRULE_DESC, BRANCHRULE_MAXBOUNDDIST, BRANCHRULE_MAXDEPTH, BRANCHRULE_NAME, BRANCHRULE_PRIORITY, DEFAULT_ABBREVIATED, DEFAULT_ABBREVPSEUDO, DEFAULT_ADDBINCONSROW, DEFAULT_ADDCLIQUE, DEFAULT_ADDNONVIOCONS, DEFAULT_APPLYCHILDBOUNDS, DEFAULT_DEEPERSCORINGFUNCTION, DEFAULT_ENFORCEMAXDOMREDS, DEFAULT_FILTERBYMAXGAIN, DEFAULT_LEVEL2AVGSCORE, DEFAULT_LEVEL2ZEROSCORE, DEFAULT_MAXNCANDS, DEFAULT_MAXNDEEPERCANDS, DEFAULT_MAXNVIOLATEDBINCONS, DEFAULT_MAXNVIOLATEDCONS, DEFAULT_MAXNVIOLATEDDOMREDS, DEFAULT_MAXPROPROUNDS, DEFAULT_MERGEDOMAINREDUCTIONS, DEFAULT_MINWEIGHT, DEFAULT_ONLYVIOLDOMREDS, DEFAULT_PREFERSIMPLEBOUNDS, DEFAULT_PROPAGATE, DEFAULT_RECURSIONDEPTH, DEFAULT_REEVALAGE, DEFAULT_REEVALAGEFSB, DEFAULT_REUSEBASIS, DEFAULT_SCORINGFUNCTION, DEFAULT_SCORINGSCORINGFUNCTION, DEFAULT_STOREUNVIOLATEDSOL, DEFAULT_UPDATEBRANCHINGRESULTS, DEFAULT_USEBINARYCONSTRAINTS, DEFAULT_USEDOMAINREDUCTION, DEFAULT_USELEVEL2DATA, DEFAULT_WORSEFACTOR, FALSE, NULL, SCIP_CALL, SCIP_LONGINT_MAX, SCIP_OKAY, SCIP_REAL_MAX, SCIPaddBoolParam(), SCIPaddCharParam(), SCIPaddIntParam(), SCIPaddLongintParam(), SCIPaddRealParam(), SCIPallocBlockMemory, SCIPincludeBranchruleBasic(), SCIPsetBranchruleCopy(), SCIPsetBranchruleExecLp(), SCIPsetBranchruleExit(), SCIPsetBranchruleExitsol(), SCIPsetBranchruleFree(), SCIPsetBranchruleInit(), and TRUE.

Referenced by SCIP_DECL_BRANCHCOPY(), and SCIPincludeDefaultPlugins().