Detailed Description

methods for branching on LP solutions, relaxation solutions, and pseudo solutions

See also: Public Variable methods contains some typical variable branching score functions

Functions
SCIP_RETCODE	SCIPgetLPBranchCands (SCIP scip, SCIP_VAR lpcands, SCIP_Real lpcandssol, SCIP_Real *lpcandsfrac, int nlpcands, int npriolpcands, int nfracimplvars)

int	SCIPgetNLPBranchCands (SCIP *scip)

int	SCIPgetNPrioLPBranchCands (SCIP *scip)

SCIP_RETCODE	SCIPgetExternBranchCands (SCIP scip, SCIP_VAR externcands, SCIP_Real externcandssol, SCIP_Real *externcandsscore, int nexterncands, int nprioexterncands, int nprioexternbins, int nprioexternints, int nprioexternimpls)

int	SCIPgetNExternBranchCands (SCIP *scip)

int	SCIPgetNPrioExternBranchCands (SCIP *scip)

int	SCIPgetNPrioExternBranchBins (SCIP *scip)

int	SCIPgetNPrioExternBranchInts (SCIP *scip)

int	SCIPgetNPrioExternBranchImpls (SCIP *scip)

int	SCIPgetNPrioExternBranchConts (SCIP *scip)

SCIP_RETCODE	SCIPaddExternBranchCand (SCIP scip, SCIP_VAR var, SCIP_Real score, SCIP_Real solval)

void	SCIPclearExternBranchCands (SCIP *scip)

SCIP_Bool	SCIPcontainsExternBranchCand (SCIP scip, SCIP_VAR var)

SCIP_RETCODE	SCIPgetPseudoBranchCands (SCIP scip, SCIP_VAR *pseudocands, int npseudocands, int *npriopseudocands)

int	SCIPgetNPseudoBranchCands (SCIP *scip)

int	SCIPgetNPrioPseudoBranchCands (SCIP *scip)

int	SCIPgetNPrioPseudoBranchBins (SCIP *scip)

int	SCIPgetNPrioPseudoBranchInts (SCIP *scip)

int	SCIPgetNPrioPseudoBranchImpls (SCIP *scip)

SCIP_Real	SCIPgetBranchScore (SCIP scip, SCIP_VAR var, SCIP_Real downgain, SCIP_Real upgain)

SCIP_Real	SCIPgetBranchScoreMultiple (SCIP scip, SCIP_VAR var, int nchildren, SCIP_Real *gains)

SCIP_Real	SCIPgetBranchingPoint (SCIP scip, SCIP_VAR var, SCIP_Real suggestion)

SCIP_Real	SCIPcalcNodeselPriority (SCIP scip, SCIP_VAR var, SCIP_BRANCHDIR branchdir, SCIP_Real targetvalue)

SCIP_Real	SCIPcalcChildEstimate (SCIP scip, SCIP_VAR var, SCIP_Real targetvalue)

SCIP_Real	SCIPcalcChildEstimateIncrease (SCIP scip, SCIP_VAR var, SCIP_Real varsol, SCIP_Real targetvalue)

SCIP_RETCODE	SCIPcreateChild (SCIP scip, SCIP_NODE *node, SCIP_Real nodeselprio, SCIP_Real estimate)

SCIP_RETCODE	SCIPbranchVar (SCIP scip, SCIP_VAR var, SCIP_NODE downchild, SCIP_NODE eqchild, SCIP_NODE **upchild)

SCIP_RETCODE	SCIPbranchVarHole (SCIP scip, SCIP_VAR var, SCIP_Real left, SCIP_Real right, SCIP_NODE downchild, SCIP_NODE upchild)

SCIP_RETCODE	SCIPbranchVarVal (SCIP scip, SCIP_VAR var, SCIP_Real val, SCIP_NODE downchild, SCIP_NODE eqchild, SCIP_NODE **upchild)

SCIP_RETCODE	SCIPbranchVarValNary (SCIP scip, SCIP_VAR var, SCIP_Real val, int n, SCIP_Real minwidth, SCIP_Real widthfactor, int *nchildren)

SCIP_RETCODE	SCIPbranchLP (SCIP scip, SCIP_RESULT result)

SCIP_RETCODE	SCIPbranchExtern (SCIP scip, SCIP_RESULT result)

SCIP_RETCODE	SCIPbranchPseudo (SCIP scip, SCIP_RESULT result)

Function Documentation

◆ SCIPgetLPBranchCands()

SCIP_RETCODE SCIPgetLPBranchCands	(	SCIP *	scip,
		SCIP_VAR ***	lpcands,
		SCIP_Real **	lpcandssol,
		SCIP_Real **	lpcandsfrac,
		int *	nlpcands,
		int *	npriolpcands,
		int *	nfracimplvars
	)

gets branching candidates for LP solution branching (fractional variables) along with solution values, fractionalities, and number of branching candidates; The number of branching candidates does NOT account for fractional implicit integer variables which should not be used for branching decisions.

Fractional implicit integer variables are stored at the positions *nlpcands to *nlpcands + *nfracimplvars - 1

branching rules should always select the branching candidate among the first npriolpcands of the candidate list

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.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure
lpcands	pointer to store the array of LP branching candidates, or NULL
lpcandssol	pointer to store the array of LP candidate solution values, or NULL
lpcandsfrac	pointer to store the array of LP candidate fractionalities, or NULL
nlpcands	pointer to store the number of LP branching candidates, or NULL
npriolpcands	pointer to store the number of candidates with maximal priority, or NULL
nfracimplvars	pointer to store the number of fractional implicit integer variables, or NULL

Definition at line 395 of file scip_branch.c.

References Scip::branchcand, FALSE, Scip::lp, SCIP_CALL, SCIP_INVALIDDATA, SCIP_LPSOLSTAT_OPTIMAL, SCIP_LPSOLSTAT_UNBOUNDEDRAY, SCIP_OKAY, SCIPbranchcandGetLPCands(), SCIPcheckStage(), SCIPerrorMessage, SCIPlpGetSolstat(), Scip::set, Scip::stat, and TRUE.

Referenced by branchingIntegralOrNonlinear(), computeBranchingPriorities(), performLPRandRounding(), performLPSimpleRounding(), SCIP_DECL_BRANCHEXECLP(), SCIP_DECL_HEUREXEC(), SCIP_DECL_SEPAEXECLP(), SCIPperformGenericDivingAlgorithm(), SCIPvisualUpdateChild(), and selectVarMultAggrBranching().

◆ SCIPgetNLPBranchCands()

int SCIPgetNLPBranchCands ( SCIP * scip )

gets number of branching candidates for LP solution branching (number of fractional variables)

Returns: the number of branching candidates for LP solution branching (number of fractional variables).

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure

Definition at line 428 of file scip_branch.c.

References Scip::branchcand, FALSE, Scip::lp, NULL, SCIP_CALL_ABORT, SCIP_LPSOLSTAT_OPTIMAL, SCIP_LPSOLSTAT_UNBOUNDEDRAY, SCIP_OKAY, SCIPABORT, SCIPbranchcandGetLPCands(), SCIPcheckStage(), SCIPerrorMessage, SCIPlpGetSolstat(), Scip::set, Scip::stat, and TRUE.

Referenced by branching(), branchingIntegralFirst(), branchingIntegralOrNonlinear(), consEnfo(), SCIP_DECL_BRANCHEXECLP(), SCIP_DECL_CONSENFOLP(), SCIP_DECL_CONSENFORELAX(), SCIP_DECL_CONSSEPALP(), SCIP_DECL_DISPOUTPUT(), SCIP_DECL_HEUREXEC(), SCIP_DECL_SEPAEXECLP(), SCIPapplyHeurDualval(), and separateOddCycles().

◆ SCIPgetNPrioLPBranchCands()

int SCIPgetNPrioLPBranchCands ( SCIP * scip )

gets number of branching candidates with maximal priority for LP solution branching

Returns: the number of branching candidates with maximal priority for LP solution branching.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure

Definition at line 466 of file scip_branch.c.

References Scip::branchcand, FALSE, Scip::lp, NULL, SCIP_CALL_ABORT, SCIP_LPSOLSTAT_OPTIMAL, SCIP_LPSOLSTAT_UNBOUNDEDRAY, SCIP_OKAY, SCIPABORT, SCIPbranchcandGetLPCands(), SCIPcheckStage(), SCIPerrorMessage, SCIPlpGetSolstat(), Scip::set, Scip::stat, and TRUE.

◆ SCIPgetExternBranchCands()

SCIP_RETCODE SCIPgetExternBranchCands	(	SCIP *	scip,
		SCIP_VAR ***	externcands,
		SCIP_Real **	externcandssol,
		SCIP_Real **	externcandsscore,
		int *	nexterncands,
		int *	nprioexterncands,
		int *	nprioexternbins,
		int *	nprioexternints,
		int *	nprioexternimpls
	)

gets external branching candidates along with solution values, scores, and number of branching candidates; these branching candidates can be used by relaxations or nonlinear constraint handlers; branching rules should always select the branching candidate among the first nprioexterncands of the candidate list

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.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Note: Candidate variables with maximal priority are ordered: binaries first, then integers, implicit integers and continuous last.

Parameters

scip	SCIP data structure
externcands	pointer to store the array of extern branching candidates, or NULL
externcandssol	pointer to store the array of extern candidate solution values, or NULL
externcandsscore	pointer to store the array of extern candidate scores, or NULL
nexterncands	pointer to store the number of extern branching candidates, or NULL
nprioexterncands	pointer to store the number of candidates with maximal priority, or NULL
nprioexternbins	pointer to store the number of binary candidates with maximal priority, or NULL
nprioexternints	pointer to store the number of integer candidates with maximal priority, or NULL
nprioexternimpls	pointer to store the number of implicit integer candidates with maximal priority, or NULL

Definition at line 511 of file scip_branch.c.

References Scip::branchcand, FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIPbranchcandGetExternCands(), SCIPcheckStage(), and TRUE.

Referenced by SCIP_DECL_BRANCHEXECEXT().

◆ SCIPgetNExternBranchCands()

int SCIPgetNExternBranchCands ( SCIP * scip )

gets number of external branching candidates

Returns: the number of external branching candidates.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure

Definition at line 543 of file scip_branch.c.

References Scip::branchcand, FALSE, NULL, SCIP_CALL_ABORT, SCIPbranchcandGetNExternCands(), SCIPcheckStage(), and TRUE.

Referenced by SCIP_DECL_DISPOUTPUT().

◆ SCIPgetNPrioExternBranchCands()

int SCIPgetNPrioExternBranchCands ( SCIP * scip )

gets number of external branching candidates with maximal branch priority

Returns: the number of external branching candidates with maximal branch priority.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure

Definition at line 563 of file scip_branch.c.

References Scip::branchcand, FALSE, NULL, SCIP_CALL_ABORT, SCIPbranchcandGetNPrioExternCands(), SCIPcheckStage(), and TRUE.

◆ SCIPgetNPrioExternBranchBins()

int SCIPgetNPrioExternBranchBins ( SCIP * scip )

gets number of binary external branching candidates with maximal branch priority

Returns: the number of binary external branching candidates with maximal branch priority.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure

Definition at line 583 of file scip_branch.c.

References Scip::branchcand, FALSE, NULL, SCIP_CALL_ABORT, SCIPbranchcandGetNPrioExternBins(), SCIPcheckStage(), and TRUE.

◆ SCIPgetNPrioExternBranchInts()

int SCIPgetNPrioExternBranchInts ( SCIP * scip )

gets number of integer external branching candidates with maximal branch priority

Returns: the number of integer external branching candidates with maximal branch priority.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure

Definition at line 603 of file scip_branch.c.

References Scip::branchcand, FALSE, NULL, SCIP_CALL_ABORT, SCIPbranchcandGetNPrioExternInts(), SCIPcheckStage(), and TRUE.

◆ SCIPgetNPrioExternBranchImpls()

int SCIPgetNPrioExternBranchImpls ( SCIP * scip )

gets number of implicit integer external branching candidates with maximal branch priority

Returns: the number of implicit integer external branching candidates with maximal branch priority.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure

Definition at line 623 of file scip_branch.c.

References Scip::branchcand, FALSE, NULL, SCIP_CALL_ABORT, SCIPbranchcandGetNPrioExternImpls(), SCIPcheckStage(), and TRUE.

◆ SCIPgetNPrioExternBranchConts()

int SCIPgetNPrioExternBranchConts ( SCIP * scip )

gets number of continuous external branching candidates with maximal branch priority

Returns: the number of continuous external branching candidates with maximal branch priority.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure

Definition at line 643 of file scip_branch.c.

References Scip::branchcand, FALSE, NULL, SCIP_CALL_ABORT, SCIPbranchcandGetNPrioExternConts(), SCIPcheckStage(), and TRUE.

◆ SCIPaddExternBranchCand()

SCIP_RETCODE SCIPaddExternBranchCand	(	SCIP *	scip,
		SCIP_VAR *	var,
		SCIP_Real	score,
		SCIP_Real	solval
	)

insert variable, its score and its solution value into the external branching candidate storage the relative difference of the current lower and upper bounds of a continuous variable must be at least epsilon

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.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure
var	variable to insert
score	score of external candidate, e.g. infeasibility
solval	value of the variable in the current solution

Definition at line 665 of file scip_branch.c.

References Scip::branchcand, FALSE, NULL, SCIP_Var::scip, SCIP_CALL, SCIP_OKAY, SCIPbranchcandAddExternCand(), SCIPcheckStage(), Scip::set, and TRUE.

Referenced by collectBranchingCands(), registerBranchingCandidates(), registerBranchingCandidatesAllUnfixed(), and SCIP_DECL_CONSENFORELAX().

◆ SCIPclearExternBranchCands()

void SCIPclearExternBranchCands ( SCIP * scip )

removes all external candidates from the storage for external branching

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure

Definition at line 689 of file scip_branch.c.

References Scip::branchcand, FALSE, NULL, SCIP_CALL_ABORT, SCIPbranchcandClearExternCands(), SCIPcheckStage(), and TRUE.

◆ SCIPcontainsExternBranchCand()

SCIP_Bool SCIPcontainsExternBranchCand	(	SCIP *	scip,
		SCIP_VAR *	var
	)

checks whether the given variable is contained in the candidate storage for external branching

Returns: whether the given variable is contained in the candidate storage for external branching.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure
var	variable to look for

Definition at line 709 of file scip_branch.c.

References Scip::branchcand, FALSE, NULL, SCIP_Var::scip, SCIP_CALL_ABORT, SCIPbranchcandContainsExternCand(), SCIPcheckStage(), and TRUE.

◆ SCIPgetPseudoBranchCands()

SCIP_RETCODE SCIPgetPseudoBranchCands	(	SCIP *	scip,
		SCIP_VAR ***	pseudocands,
		int *	npseudocands,
		int *	npriopseudocands
	)

gets branching candidates for pseudo solution branching (non-fixed variables) along with the number of candidates

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.

Precondition

This method can be called if scip is in one of the following stages:

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure
pseudocands	pointer to store the array of pseudo branching candidates, or NULL
npseudocands	pointer to store the number of pseudo branching candidates, or NULL
npriopseudocands	pointer to store the number of candidates with maximal priority, or NULL

Definition at line 733 of file scip_branch.c.

References Scip::branchcand, FALSE, SCIP_CALL, SCIP_OKAY, SCIPbranchcandGetPseudoCands(), SCIPcheckStage(), Scip::set, Scip::transprob, and TRUE.

Referenced by branch(), countSparseSol(), SCIP_DECL_BRANCHEXECLP(), SCIP_DECL_BRANCHEXECPS(), and SCIP_DECL_HEUREXEC().

◆ SCIPgetNPseudoBranchCands()

int SCIPgetNPseudoBranchCands ( SCIP * scip )

gets number of branching candidates for pseudo solution branching (non-fixed variables)

Returns: the number branching candidates for pseudo solution branching (non-fixed variables).

Precondition

This method can be called if scip is in one of the following stages:

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure

Definition at line 758 of file scip_branch.c.

References Scip::branchcand, FALSE, SCIP_CALL_ABORT, SCIPbranchcandGetNPseudoCands(), SCIPcheckStage(), and TRUE.

Referenced by applyBoundHeur(), applyOptcumulativeFixings(), applyVbounds(), applyVboundsFixings(), checkFeasSubtree(), checkSolution(), countSparseSol(), enforceConstraint(), SCIP_DECL_HEUREXEC(), and SCIPapplyHeurDualval().

◆ SCIPgetNPrioPseudoBranchCands()

int SCIPgetNPrioPseudoBranchCands ( SCIP * scip )

gets number of branching candidates with maximal branch priority for pseudo solution branching

Returns: the number of branching candidates with maximal branch priority for pseudo solution branching.

Precondition

This method can be called if scip is in one of the following stages:

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure

Definition at line 777 of file scip_branch.c.

References Scip::branchcand, FALSE, SCIP_CALL_ABORT, SCIPbranchcandGetNPrioPseudoCands(), SCIPcheckStage(), and TRUE.

◆ SCIPgetNPrioPseudoBranchBins()

int SCIPgetNPrioPseudoBranchBins ( SCIP * scip )

gets number of binary branching candidates with maximal branch priority for pseudo solution branching

Returns: the number of binary branching candidates with maximal branch priority for pseudo solution branching.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure

Definition at line 795 of file scip_branch.c.

References Scip::branchcand, FALSE, SCIP_CALL_ABORT, SCIPbranchcandGetNPrioPseudoBins(), SCIPcheckStage(), and TRUE.

Referenced by fixVariable().

◆ SCIPgetNPrioPseudoBranchInts()

int SCIPgetNPrioPseudoBranchInts ( SCIP * scip )

gets number of integer branching candidates with maximal branch priority for pseudo solution branching

Returns: the number of integer branching candidates with maximal branch priority for pseudo solution branching.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure

Definition at line 813 of file scip_branch.c.

References Scip::branchcand, FALSE, SCIP_CALL_ABORT, SCIPbranchcandGetNPrioPseudoInts(), SCIPcheckStage(), and TRUE.

◆ SCIPgetNPrioPseudoBranchImpls()

int SCIPgetNPrioPseudoBranchImpls ( SCIP * scip )

gets number of implicit integer branching candidates with maximal branch priority for pseudo solution branching

Returns: the number of implicit integer branching candidates with maximal branch priority for pseudo solution branching.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure

Definition at line 831 of file scip_branch.c.

References Scip::branchcand, FALSE, SCIP_CALL_ABORT, SCIPbranchcandGetNPrioPseudoImpls(), SCIPcheckStage(), and TRUE.

◆ SCIPgetBranchScore()

SCIP_Real SCIPgetBranchScore	(	SCIP *	scip,
		SCIP_VAR *	var,
		SCIP_Real	downgain,
		SCIP_Real	upgain
	)

calculates the branching score out of the gain predictions for a binary branching

Returns: the branching score out of the gain predictions for a binary branching.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure
var	variable, of which the branching factor should be applied, or NULL
downgain	prediction of objective gain for rounding downwards
upgain	prediction of objective gain for rounding upwards

Definition at line 849 of file scip_branch.c.

References FALSE, NULL, SCIP_Var::scip, SCIP_CALL_ABORT, SCIPbranchGetScore(), SCIPcheckStage(), Scip::set, and TRUE.

Referenced by execRelpscost(), getNActiveConsScore(), SCIP_DECL_BRANCHEXECLP(), SCIPselectVarPseudoStrongBranching(), SCIPselectVarStrongBranching(), scoreBranchingCandidates(), selectVarMultAggrBranching(), and updateBestCandidate().

◆ SCIPgetBranchScoreMultiple()

SCIP_Real SCIPgetBranchScoreMultiple	(	SCIP *	scip,
		SCIP_VAR *	var,
		int	nchildren,
		SCIP_Real *	gains
	)

calculates the branching score out of the gain predictions for a branching with arbitrary many children

Returns: the branching score out of the gain predictions for a branching with arbitrary many children.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure
var	variable, of which the branching factor should be applied, or NULL
nchildren	number of children that the branching will create
gains	prediction of objective gain for each child

Definition at line 872 of file scip_branch.c.

References FALSE, SCIP_Var::scip, SCIP_CALL_ABORT, SCIPbranchGetScoreMultiple(), SCIPcheckStage(), Scip::set, and TRUE.

Referenced by runVanillaStrongBranching(), and SCIPselectVarPseudoStrongBranching().

◆ SCIPgetBranchingPoint()

SCIP_Real SCIPgetBranchingPoint	(	SCIP *	scip,
		SCIP_VAR *	var,
		SCIP_Real	suggestion
	)

computes a branching point for a continuous or discrete variable

See also: SCIPbranchGetBranchingPoint

Returns: the branching point for a continuous or discrete variable.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure
var	variable, of which the branching point should be computed
suggestion	suggestion for branching point, or SCIP_INVALID if no suggestion

Definition at line 897 of file scip_branch.c.

References FALSE, SCIP_Var::scip, SCIP_CALL_ABORT, SCIPbranchGetBranchingPoint(), SCIPcheckStage(), Scip::set, Scip::tree, and TRUE.

Referenced by branching(), performBranchingSol(), SCIP_DECL_BRANCHEXECEXT(), scoreBranchingCandidates(), and updateBestCandidate().

◆ SCIPcalcNodeselPriority()

SCIP_Real SCIPcalcNodeselPriority	(	SCIP *	scip,
		SCIP_VAR *	var,
		SCIP_BRANCHDIR	branchdir,
		SCIP_Real	targetvalue
	)

calculates the node selection priority for moving the given variable's LP value to the given target value; this node selection priority can be given to the SCIPcreateChild() call

Returns: the node selection priority for moving the given variable's LP value to the given target value.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure
var	variable on which the branching is applied
branchdir	type of branching that was performed: upwards, downwards, or fixed; fixed should only be used, when both bounds changed
targetvalue	new value of the variable in the child node

Definition at line 920 of file scip_branch.c.

References FALSE, SCIP_Var::scip, SCIP_CALL_ABORT, SCIPcheckStage(), SCIPtreeCalcNodeselPriority(), Scip::set, Scip::stat, Scip::tree, and TRUE.

Referenced by branchBalancedCardinality(), branchOnBin(), branchUnbalancedCardinality(), createNAryBranch(), enforceConflictgraph(), enforceConssSOS1(), and enforceSOS2().

◆ SCIPcalcChildEstimate()

SCIP_Real SCIPcalcChildEstimate	(	SCIP *	scip,
		SCIP_VAR *	var,
		SCIP_Real	targetvalue
	)

calculates an estimate for the objective of the best feasible solution contained in the subtree after applying the given branching; this estimate can be given to the SCIPcreateChild() call

Returns: the estimate for the objective of the best feasible solution contained in the subtree after applying the given branching.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure
var	variable on which the branching is applied
targetvalue	new value of the variable in the child node

Definition at line 947 of file scip_branch.c.

References FALSE, SCIP_Var::scip, SCIP_CALL_ABORT, SCIPcheckStage(), SCIPtreeCalcChildEstimate(), Scip::set, Scip::stat, Scip::tree, and TRUE.

Referenced by branchOnBin(), branchUnbalancedCardinality(), createNAryBranch(), enforceConssSOS1(), enforceIndicators(), and performBranchingNoSol().

◆ SCIPcalcChildEstimateIncrease()

SCIP_Real SCIPcalcChildEstimateIncrease	(	SCIP *	scip,
		SCIP_VAR *	var,
		SCIP_Real	varsol,
		SCIP_Real	targetvalue
	)

calculates the increase of the estimate for the objective of the best feasible solution contained in the subtree after applying the given branching

Returns: the increase of the estimate for the objective of the best feasible solution contained in the subtree after applying the given branching.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure
var	variable on which the branching is applied
varsol	solution value of variable
targetvalue	new value of the variable in the child node

Definition at line 971 of file scip_branch.c.

References MIN, NULL, SCIP_Real, SCIP_VARTYPE_CONTINUOUS, SCIPsetFeasCeil(), SCIPsetFeasFloor(), SCIPvarGetPseudocost(), SCIPvarGetType(), Scip::set, and Scip::stat.

Referenced by branchBalancedCardinality(), branchUnbalancedCardinality(), enforceConflictgraph(), enforceConssSOS1(), and enforceSOS2().

◆ SCIPcreateChild()

SCIP_RETCODE SCIPcreateChild	(	SCIP *	scip,
		SCIP_NODE **	node,
		SCIP_Real	nodeselprio,
		SCIP_Real	estimate
	)

creates a child node of the focus node

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.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure
node	pointer to node data structure
nodeselprio	node selection priority of new node
estimate	estimate for(transformed) objective value of best feasible solution in subtree

Definition at line 1017 of file scip_branch.c.

References FALSE, Scip::mem, NULL, SCIP_Mem::probmem, SCIP_CALL, SCIP_OKAY, SCIPcheckStage(), SCIPnodeCreateChild(), Scip::set, Scip::stat, Scip::tree, and TRUE.

Referenced by branchBalancedCardinality(), branchCons(), branchOnBin(), branchUnbalancedCardinality(), createNAryBranch(), enforceConflictgraph(), enforceConssSOS1(), enforceIndicators(), enforceSOS2(), performBranchingNoSol(), SCIP_DECL_BRANCHEXECLP(), and SCIP_DECL_BRANCHEXECPS().

◆ SCIPbranchVar()

SCIP_RETCODE SCIPbranchVar	(	SCIP *	scip,
		SCIP_VAR *	var,
		SCIP_NODE **	downchild,
		SCIP_NODE **	eqchild,
		SCIP_NODE **	upchild
	)

branches on a non-continuous variable v using the current LP or pseudo solution; if solution value x' is fractional, two child nodes will be created (x <= floor(x'), x >= ceil(x')), if solution value is integral, the x' is equal to lower or upper bound of the branching variable and the bounds of v are finite, then two child nodes will be created (x <= x'', x >= x''+1 with x'' = floor((lb + ub)/2)), otherwise (up to) three child nodes will be created (x <= x'-1, x == x', x >= x'+1)

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.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure
var	variable to branch on
downchild	pointer to return the left child with variable rounded down, or NULL
eqchild	pointer to return the middle child with variable fixed, or NULL
upchild	pointer to return the right child with variable rounded up, or NULL

Definition at line 1050 of file scip_branch.c.

References Scip::branchcand, Scip::eventqueue, FALSE, Scip::lp, Scip::mem, Scip::origprob, SCIP_Mem::probmem, Scip::reopt, SCIP_Var::scip, SCIP_CALL, SCIP_INVALID, SCIP_INVALIDDATA, SCIP_OKAY, SCIP_VARTYPE_CONTINUOUS, SCIPcheckStage(), SCIPerrorMessage, SCIPsetIsEQ(), SCIPtreeBranchVar(), SCIPvarGetLbLocal(), SCIPvarGetName(), SCIPvarGetType(), SCIPvarGetUbLocal(), Scip::set, Scip::stat, Scip::transprob, Scip::tree, and TRUE.

Referenced by performBranchingNoSol(), SCIP_DECL_BRANCHEXECLP(), and SCIP_DECL_BRANCHEXECPS().

◆ SCIPbranchVarHole()

SCIP_RETCODE SCIPbranchVarHole	(	SCIP *	scip,
		SCIP_VAR *	var,
		SCIP_Real	left,
		SCIP_Real	right,
		SCIP_NODE **	downchild,
		SCIP_NODE **	upchild
	)

branches a variable x using a given domain hole; two child nodes (x <= left, x >= right) are created

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.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure
var	variable to branch on
left	left side of the domain hole
right	right side of the domain hole
downchild	pointer to return the left child (x <= left), or NULL
upchild	pointer to return the right child (x >= right), or NULL

Definition at line 1091 of file scip_branch.c.

References Scip::branchcand, Scip::eventqueue, FALSE, Scip::lp, Scip::mem, Scip::origprob, SCIP_Mem::probmem, Scip::reopt, SCIP_Var::scip, SCIP_CALL, SCIP_OKAY, SCIPcheckStage(), SCIPtreeBranchVarHole(), Scip::set, Scip::stat, Scip::transprob, Scip::tree, and TRUE.

Referenced by applyAlternativeBoundsBranching().

◆ SCIPbranchVarVal()

SCIP_RETCODE SCIPbranchVarVal	(	SCIP *	scip,
		SCIP_VAR *	var,
		SCIP_Real	val,
		SCIP_NODE **	downchild,
		SCIP_NODE **	eqchild,
		SCIP_NODE **	upchild
	)

branches on a variable x using a given value x'; for continuous variables with relative domain width larger epsilon, x' must not be one of the bounds; two child nodes (x <= x', x >= x') are created; for integer variables, if solution value x' is fractional, two child nodes are created (x <= floor(x'), x >= ceil(x')), if x' is integral, three child nodes are created (x <= x'-1, x == x', x >= x'+1)

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.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure
var	variable to branch on
val	value to branch on
downchild	pointer to return the left child with variable rounded down, or NULL
eqchild	pointer to return the middle child with variable fixed, or NULL
upchild	pointer to return the right child with variable rounded up, or NULL

Definition at line 1126 of file scip_branch.c.

References Scip::branchcand, Scip::eventqueue, FALSE, Scip::lp, Scip::mem, Scip::origprob, SCIP_Mem::probmem, Scip::reopt, SCIP_Var::scip, SCIP_CALL, SCIP_INVALIDDATA, SCIP_OKAY, SCIP_VARTYPE_CONTINUOUS, SCIPcheckStage(), SCIPerrorMessage, SCIPisInfinity(), SCIPisLT(), SCIPisRelEQ(), SCIPsetIsEQ(), SCIPtreeBranchVar(), SCIPvarGetLbLocal(), SCIPvarGetName(), SCIPvarGetType(), SCIPvarGetUbLocal(), Scip::set, Scip::stat, Scip::transprob, Scip::tree, and TRUE.

Referenced by branch(), branching(), execRelpscost(), performBranchingSol(), and SCIP_DECL_BRANCHEXECEXT().

◆ SCIPbranchVarValNary()

SCIP_RETCODE SCIPbranchVarValNary	(	SCIP *	scip,
		SCIP_VAR *	var,
		SCIP_Real	val,
		int	n,
		SCIP_Real	minwidth,
		SCIP_Real	widthfactor,
		int *	nchildren
	)

n-ary branching on a variable x using a given value

Branches on variable x such that up to n/2 children are created on each side of the usual branching value. The branching value is selected as in SCIPbranchVarVal(). The parameters minwidth and widthfactor determine the domain width of the branching variable in the child nodes. If n is odd, one child with domain width 'width' and having the branching value in the middle is created. Otherwise, two children with domain width 'width' and being left and right of the branching value are created. Next further nodes to the left and right are created, where width is multiplied by widthfactor with increasing distance from the first nodes. The initial width is calculated such that n/2 nodes are created to the left and to the right of the branching value. If this value is below minwidth, the initial width is set to minwidth, which may result in creating less than n nodes.

Giving a large value for widthfactor results in creating children with small domain when close to the branching value and large domain when closer to the current variable bounds. That is, setting widthfactor to a very large value and n to 3 results in a ternary branching where the branching variable is mostly fixed in the middle child. Setting widthfactor to 1.0 results in children where the branching variable always has the same domain width (except for one child if the branching value is not in the middle).

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.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure
var	variable to branch on
val	value to branch on
n	attempted number of children to be created, must be >= 2
minwidth	minimal domain width in children
widthfactor	multiplier for children domain width with increasing distance from val, must be >= 1.0
nchildren	pointer to store number of created children, or NULL

Definition at line 1189 of file scip_branch.c.

References Scip::branchcand, Scip::eventqueue, FALSE, Scip::lp, Scip::mem, Scip::origprob, SCIP_Mem::probmem, Scip::reopt, SCIP_Var::scip, SCIP_CALL, SCIP_INVALIDDATA, SCIP_OKAY, SCIP_VARTYPE_CONTINUOUS, SCIPcheckStage(), SCIPerrorMessage, SCIPisInfinity(), SCIPisLT(), SCIPisRelEQ(), SCIPsetIsEQ(), SCIPtreeBranchVarNary(), SCIPvarGetLbLocal(), SCIPvarGetName(), SCIPvarGetType(), SCIPvarGetUbLocal(), Scip::set, Scip::stat, Scip::transprob, Scip::tree, and TRUE.

Referenced by SCIP_DECL_BRANCHEXECEXT().

◆ SCIPbranchLP()

SCIP_RETCODE SCIPbranchLP	(	SCIP *	scip,
		SCIP_RESULT *	result
	)

calls branching rules to branch on an LP solution; if no fractional variables exist, the result is SCIP_DIDNOTRUN; if the branch priority of an unfixed variable is larger than the maximal branch priority of the fractional variables, pseudo solution branching is applied on the unfixed variables with maximal branch priority

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.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure
result	pointer to store the result of the branching (s. branch.h)

Definition at line 1234 of file scip_branch.c.

References Scip::branchcand, SCIP_Primal::cutoffbound, Scip::eventqueue, FALSE, Scip::lp, Scip::mem, Scip::origprob, Scip::primal, SCIP_Mem::probmem, Scip::reopt, SCIP_CALL, SCIP_OKAY, SCIPbranchExecLP(), SCIPcheckStage(), Scip::sepastore, Scip::set, Scip::stat, Scip::transprob, Scip::tree, and TRUE.

Referenced by SCIP_DECL_CONSENFOLP().

◆ SCIPbranchExtern()

SCIP_RETCODE SCIPbranchExtern	(	SCIP *	scip,
		SCIP_RESULT *	result
	)

calls branching rules to branch on a external candidates; if no such candidates exist, the result is SCIP_DIDNOTRUN

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.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure
result	pointer to store the result of the branching (s. branch.h)

Definition at line 1258 of file scip_branch.c.

References Scip::branchcand, SCIP_Primal::cutoffbound, Scip::eventqueue, FALSE, Scip::lp, Scip::mem, Scip::origprob, Scip::primal, SCIP_Mem::probmem, Scip::reopt, SCIP_CALL, SCIP_OKAY, SCIPbranchExecExtern(), SCIPcheckStage(), Scip::sepastore, Scip::set, Scip::stat, Scip::transprob, Scip::tree, and TRUE.

Referenced by SCIP_DECL_CONSENFORELAX().

◆ SCIPbranchPseudo()

SCIP_RETCODE SCIPbranchPseudo	(	SCIP *	scip,
		SCIP_RESULT *	result
	)

calls branching rules to branch on a pseudo solution; if no unfixed variables exist, the result is SCIP_DIDNOTRUN

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.

Precondition

This method can be called if scip is in one of the following stages:

SCIP_STAGE_SOLVING

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure
result	pointer to store the result of the branching (s. branch.h)

Definition at line 1282 of file scip_branch.c.

References Scip::branchcand, SCIP_Primal::cutoffbound, Scip::eventqueue, FALSE, Scip::lp, Scip::mem, Scip::origprob, Scip::primal, SCIP_Mem::probmem, Scip::reopt, SCIP_CALL, SCIP_OKAY, SCIPbranchExecPseudo(), SCIPcheckStage(), Scip::set, Scip::stat, Scip::transprob, Scip::tree, and TRUE.

SCIP

Detailed Description

Functions

Function Documentation

◆ SCIPgetLPBranchCands()

◆ SCIPgetNLPBranchCands()

◆ SCIPgetNPrioLPBranchCands()

◆ SCIPgetExternBranchCands()

◆ SCIPgetNExternBranchCands()

◆ SCIPgetNPrioExternBranchCands()

◆ SCIPgetNPrioExternBranchBins()

◆ SCIPgetNPrioExternBranchInts()

◆ SCIPgetNPrioExternBranchImpls()

◆ SCIPgetNPrioExternBranchConts()

◆ SCIPaddExternBranchCand()

◆ SCIPclearExternBranchCands()

◆ SCIPcontainsExternBranchCand()

◆ SCIPgetPseudoBranchCands()

◆ SCIPgetNPseudoBranchCands()

◆ SCIPgetNPrioPseudoBranchCands()

◆ SCIPgetNPrioPseudoBranchBins()

◆ SCIPgetNPrioPseudoBranchInts()

◆ SCIPgetNPrioPseudoBranchImpls()

◆ SCIPgetBranchScore()

◆ SCIPgetBranchScoreMultiple()

◆ SCIPgetBranchingPoint()

◆ SCIPcalcNodeselPriority()

◆ SCIPcalcChildEstimate()

◆ SCIPcalcChildEstimateIncrease()

◆ SCIPcreateChild()

◆ SCIPbranchVar()

◆ SCIPbranchVarHole()

◆ SCIPbranchVarVal()

◆ SCIPbranchVarValNary()

◆ SCIPbranchLP()

◆ SCIPbranchExtern()

◆ SCIPbranchPseudo()