Detailed Description

methods to initiate and control the probing mode of SCIP

Functions
SCIP_EXPORT SCIP_Bool	SCIPinProbing (SCIP *scip)

SCIP_EXPORT SCIP_RETCODE	SCIPstartProbing (SCIP *scip)

SCIP_EXPORT SCIP_RETCODE	SCIPnewProbingNode (SCIP *scip)

SCIP_EXPORT int	SCIPgetProbingDepth (SCIP *scip)

SCIP_EXPORT SCIP_RETCODE	SCIPbacktrackProbing (SCIP *scip, int probingdepth)

SCIP_EXPORT SCIP_RETCODE	SCIPendProbing (SCIP *scip)

SCIP_EXPORT SCIP_RETCODE	SCIPchgVarLbProbing (SCIP scip, SCIP_VAR var, SCIP_Real newbound)

SCIP_EXPORT SCIP_RETCODE	SCIPchgVarUbProbing (SCIP scip, SCIP_VAR var, SCIP_Real newbound)

SCIP_EXPORT SCIP_Real	SCIPgetVarObjProbing (SCIP scip, SCIP_VAR var)

SCIP_EXPORT SCIP_RETCODE	SCIPfixVarProbing (SCIP scip, SCIP_VAR var, SCIP_Real fixedval)

SCIP_EXPORT SCIP_RETCODE	SCIPchgVarObjProbing (SCIP scip, SCIP_VAR var, SCIP_Real newobj)

SCIP_EXPORT SCIP_Bool	SCIPisObjChangedProbing (SCIP *scip)

SCIP_EXPORT SCIP_RETCODE	SCIPpropagateProbing (SCIP scip, int maxproprounds, SCIP_Bool cutoff, SCIP_Longint *ndomredsfound)

SCIP_EXPORT SCIP_RETCODE	SCIPpropagateProbingImplications (SCIP scip, SCIP_Bool cutoff)

SCIP_EXPORT SCIP_RETCODE	SCIPsolveProbingLP (SCIP scip, int itlim, SCIP_Bool lperror, SCIP_Bool *cutoff)

SCIP_EXPORT SCIP_RETCODE	SCIPsolveProbingLPWithPricing (SCIP scip, SCIP_Bool pretendroot, SCIP_Bool displayinfo, int maxpricerounds, SCIP_Bool lperror, SCIP_Bool *cutoff)

SCIP_EXPORT SCIP_RETCODE	SCIPsetProbingLPState (SCIP scip, SCIP_LPISTATE lpistate, SCIP_LPINORMS *lpinorms, SCIP_Bool primalfeas, SCIP_Bool dualfeas)

SCIP_EXPORT SCIP_RETCODE	SCIPaddRowProbing (SCIP scip, SCIP_ROW row)

SCIP_EXPORT SCIP_RETCODE	SCIPapplyCutsProbing (SCIP scip, SCIP_Bool cutoff)

SCIP_EXPORT SCIP_RETCODE	SCIPsolveProbingRelax (SCIP scip, SCIP_Bool cutoff)

SCIP_EXPORT SCIP_RETCODE	SCIPgetDivesetScore (SCIP scip, SCIP_DIVESET diveset, SCIP_DIVETYPE divetype, SCIP_VAR divecand, SCIP_Real divecandsol, SCIP_Real divecandfrac, SCIP_Real candscore, SCIP_Bool *roundup)

SCIP_EXPORT void	SCIPupdateDivesetLPStats (SCIP scip, SCIP_DIVESET diveset, SCIP_Longint niterstoadd)

SCIP_EXPORT void	SCIPupdateDivesetStats (SCIP scip, SCIP_DIVESET diveset, int nprobingnodes, int nbacktracks, SCIP_Longint nsolsfound, SCIP_Longint nbestsolsfound, SCIP_Longint nconflictsfound, SCIP_Bool leavewassol)

SCIP_EXPORT SCIP_RETCODE	SCIPgetDiveBoundChanges (SCIP scip, SCIP_DIVESET diveset, SCIP_SOL sol, SCIP_Bool success, SCIP_Bool *infeasible)

SCIP_EXPORT SCIP_RETCODE	SCIPaddDiveBoundChange (SCIP scip, SCIP_VAR var, SCIP_BRANCHDIR dir, SCIP_Real value, SCIP_Bool preferred)

SCIP_EXPORT void	SCIPgetDiveBoundChangeData (SCIP scip, SCIP_VAR variables, SCIP_BRANCHDIR directions, SCIP_Real *values, int ndivebdchgs, SCIP_Bool preferred)

SCIP_EXPORT void	SCIPclearDiveBoundChanges (SCIP *scip)

Function Documentation

◆ SCIPinProbing()

SCIP_EXPORT SCIP_Bool SCIPinProbing ( SCIP * scip )

returns whether we are in probing mode; probing mode is activated via SCIPstartProbing() and stopped via SCIPendProbing()

Returns: TRUE, if SCIP is currently in probing mode, otherwise FALSE

Precondition

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

Parameters

scip	SCIP data structure

Definition at line 87 of file scip_probing.c.

References FALSE, SCIP_CALL_ABORT, SCIPcheckStage(), SCIPtreeProbing(), Scip::tree, and TRUE.

Referenced by analyzeConflict(), analyzeConflictOne(), analyzeConflictZero(), applyGenVBounds(), applyProbingVar(), applyVbounds(), checkRedundancy(), consdataDeletePos(), execGenVBounds(), filterExistingLP(), fixIntegerVariable(), fixIntegerVariableLb(), fixIntegerVariableUb(), performRandRounding(), polishSolution(), processBinvarFixings(), propagateAllConss(), propagateBounds(), propagateBoundsCons(), propagateBoundsTightenVarLb(), propagateBoundsTightenVarUb(), propagateCons(), propagateConstraintSides(), propagatePackingPartitioningCons(), propIndicator(), reformulate(), removeFixedBinvars(), resolvePropagationCoretimes(), SCIP_DECL_CONSPRESOL(), SCIP_DECL_CONSPROP(), SCIP_DECL_EVENTEXEC(), SCIP_DECL_PRESOLEXEC(), SCIP_DECL_PROPEXEC(), SCIP_DECL_PROPPRESOL(), SCIP_DECL_RELAXEXEC(), SCIPaddDiveBoundChange(), SCIPapplyLockFixings(), SCIPbendersExec(), SCIPbendersFreeSubproblem(), SCIPbendersSetMastervarsCont(), SCIPbendersSolveSubproblem(), SCIPbendersSolveSubproblemCIP(), SCIPbendersSolveSubproblemLP(), SCIPchgVarLb(), SCIPchgVarLbGlobal(), SCIPchgVarUb(), SCIPchgVarUbGlobal(), SCIPgetDiveBoundChangeData(), SCIPgetDiveBoundChanges(), SCIPgetVarStrongbranchWithPropagation(), SCIPinferVarLbCons(), SCIPinferVarLbProp(), SCIPinferVarUbCons(), SCIPinferVarUbProp(), SCIPisObjChangedProbing(), SCIPrelaxExec(), SCIPstartStrongbranch(), SCIPtightenVarLb(), SCIPtightenVarLbGlobal(), SCIPtightenVarUb(), SCIPtightenVarUbGlobal(), SCIPupdateDivesetStats(), selectVarStart(), solveBilinearLP(), solveIndependentCons(), solveSubproblem(), storeAllBilinearTerms(), tightenBounds(), tightenedIntvar(), updateSubproblemLowerbound(), and varProcessBoundChanges().

◆ SCIPstartProbing()

SCIP_EXPORT SCIP_RETCODE SCIPstartProbing ( SCIP * scip )

initiates probing, making methods SCIPnewProbingNode(), SCIPbacktrackProbing(), SCIPchgVarLbProbing(), SCIPchgVarUbProbing(), SCIPfixVarProbing(), SCIPpropagateProbing(), and SCIPsolveProbingLP() available

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:

Note: The collection of variable statistics is turned off during probing. If these statistics should be collected during probing use the method SCIPenableVarHistory() to turn the collection explicitly on.

Parameters

scip	SCIP data structure

Definition at line 109 of file scip_probing.c.

References FALSE, Scip::lp, Scip::mem, NULL, SCIP_Mem::probmem, Scip::relaxation, SCIP_CALL, SCIP_INVALIDCALL, SCIP_OKAY, SCIPcheckStage(), SCIPerrorMessage, SCIPlpDiving(), SCIPstatDisableVarHistory(), SCIPswapPointers(), SCIPtreeProbing(), SCIPtreeStartProbing(), Scip::sepastore, Scip::sepastoreprobing, Scip::set, Scip::stat, Scip::transprob, Scip::tree, and TRUE.

Referenced by applyBoundHeur(), applyCompletesol(), applyOptcumulative(), applyVbounds(), executeStrongBranching(), fixAndPropagate(), performRandRounding(), performStrongbranchSOS1(), propagateCons(), SCIP_DECL_HEUREXEC(), SCIPapplyProbingVar(), SCIPbendersComputeSubproblemLowerbound(), SCIPbendersSetupSubproblem(), SCIPbendersSolveSubproblem(), SCIPperformGenericDivingAlgorithm(), selectVarMultAggrBranching(), tryOneOpt(), trySolCandidate(), and updateSubproblemLowerbound().

◆ SCIPnewProbingNode()

SCIP_EXPORT SCIP_RETCODE SCIPnewProbingNode ( SCIP * scip )

creates a new probing sub node, whose changes can be undone by backtracking to a higher node in the probing path with a call to SCIPbacktrackProbing(); using a sub node for each set of probing bound changes can improve conflict analysis

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:

Parameters

scip	SCIP data structure

Definition at line 155 of file scip_probing.c.

References FALSE, Scip::lp, Scip::mem, SCIP_Mem::probmem, SCIP_CALL, SCIP_INVALIDCALL, SCIP_MAXDEPTHLEVEL, SCIP_OKAY, SCIPcheckStage(), SCIPerrorMessage, SCIPtreeCreateProbingNode(), SCIPtreeProbing(), SCIPwarningMessage(), Scip::set, Scip::tree, and TRUE.

Referenced by applyCliqueFixings(), applyOptcumulativeFixings(), applyVboundsFixings(), executeStrongBranching(), performFixing(), performRandRounding(), performStrongbranchWithPropagation(), propagateCons(), SCIP_DECL_HEUREXEC(), SCIPapplyLockFixings(), SCIPperformGenericDivingAlgorithm(), selectVarMultAggrBranching(), solveBilinearLP(), tightenVariables(), tryOneOpt(), and trySolCandidate().

◆ SCIPgetProbingDepth()

SCIP_EXPORT int SCIPgetProbingDepth ( SCIP * scip )

returns the current probing depth

Returns: the probing depth, i.e. the number of probing sub nodes existing in the probing path

Precondition

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

Parameters

scip	SCIP data structure

Definition at line 188 of file scip_probing.c.

References FALSE, SCIP_CALL_ABORT, SCIPABORT, SCIPcheckStage(), SCIPerrorMessage, SCIPtreeGetProbingDepth(), SCIPtreeProbing(), Scip::tree, and TRUE.

Referenced by applyBoundHeur(), applyCliqueFixings(), applyOptcumulativeFixings(), applyVboundsFixings(), executeBranchingRecursive(), fixAndPropagate(), SCIP_DECL_HEUREXEC(), SCIPapplyLockFixings(), SCIPendStrongbranch(), SCIPperformGenericDivingAlgorithm(), selectVarRecursive(), selectVarStart(), and tightenVariables().

◆ SCIPbacktrackProbing()

SCIP_EXPORT SCIP_RETCODE SCIPbacktrackProbing	(	SCIP *	scip,
		int	probingdepth
	)

undoes all changes to the problem applied in probing up to the given probing depth; the changes of the probing node of the given probing depth are the last ones that remain active; changes that were applied before calling SCIPnewProbingNode() cannot be undone

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:

Parameters

scip	SCIP data structure
probingdepth	probing depth of the node in the probing path that should be reactivated

Definition at line 215 of file scip_probing.c.

References Scip::branchcand, Scip::cliquetable, Scip::eventfilter, Scip::eventqueue, FALSE, Scip::lp, Scip::mem, Scip::origprob, Scip::primal, SCIP_Mem::probmem, Scip::reopt, SCIP_CALL, SCIP_INVALIDCALL, SCIP_INVALIDDATA, SCIP_OKAY, SCIPcheckStage(), SCIPerrorMessage, SCIPtreeBacktrackProbing(), SCIPtreeGetProbingDepth(), SCIPtreeProbing(), Scip::set, Scip::stat, Scip::transprob, Scip::tree, and TRUE.

Referenced by applyBoundHeur(), applyCliqueFixings(), applyOptcumulativeFixings(), applyVboundsFixings(), executeBranchingRecursive(), fixAndPropagate(), performStrongbranchWithPropagation(), SCIP_DECL_HEUREXEC(), SCIPapplyLockFixings(), SCIPperformGenericDivingAlgorithm(), selectVarMultAggrBranching(), solveBilinearLP(), tightenVariables(), and tryOneOpt().

◆ SCIPendProbing()

SCIP_EXPORT SCIP_RETCODE SCIPendProbing ( SCIP * scip )

quits probing and resets bounds and constraints to the focus node's environment

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:

Parameters

scip	SCIP data structure

Definition at line 250 of file scip_probing.c.

References Scip::branchcand, Scip::cliquetable, Scip::eventfilter, Scip::eventqueue, FALSE, Scip::lp, Scip::mem, Scip::messagehdlr, NULL, Scip::origprob, Scip::primal, SCIP_Mem::probmem, Scip::relaxation, Scip::reopt, SCIP_CALL, SCIP_INVALIDCALL, SCIP_OKAY, SCIPcheckStage(), SCIPerrorMessage, SCIPsepastoreGetNCuts(), SCIPstatEnableVarHistory(), SCIPswapPointers(), SCIPtreeEndProbing(), SCIPtreeProbing(), Scip::sepastore, Scip::sepastoreprobing, Scip::set, Scip::stat, Scip::transprob, Scip::tree, and TRUE.

Referenced by applyBoundHeur(), applyCompletesol(), applyOptcumulative(), applyVbounds(), executeStrongBranching(), fixAndPropagate(), performRandRounding(), performStrongbranchSOS1(), propagateCons(), SCIP_DECL_HEUREXEC(), SCIPapplyProbingVar(), SCIPbendersFreeSubproblem(), SCIPbendersSetMastervarsCont(), SCIPbendersSolveSubproblemCIP(), SCIPperformGenericDivingAlgorithm(), selectVarMultAggrBranching(), tryOneOpt(), trySolCandidate(), and updateSubproblemLowerbound().

◆ SCIPchgVarLbProbing()

SCIP_EXPORT SCIP_RETCODE SCIPchgVarLbProbing	(	SCIP *	scip,
		SCIP_VAR *	var,
		SCIP_Real	newbound
	)

injects a change of variable's lower bound into current probing node; the same can also be achieved with a call to SCIPchgVarLb(), but in this case, the bound change would be treated like a deduction instead of a branching decision

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:

Parameters

scip	SCIP data structure
var	variable to change the bound for
newbound	new value for bound

Definition at line 291 of file scip_probing.c.

References Scip::branchcand, Scip::cliquetable, Scip::eventqueue, FALSE, Scip::lp, Scip::mem, Scip::origprob, SCIP_Mem::probmem, Scip::reopt, SCIP_BOUNDTYPE_LOWER, SCIP_CALL, SCIP_INVALIDCALL, SCIP_NODETYPE_PROBINGNODE, SCIP_OKAY, SCIP_STAGE_SOLVING, SCIPcheckStage(), SCIPerrorMessage, SCIPgetStage(), SCIPisInfinity(), SCIPnodeAddBoundchg(), SCIPnodeGetType(), SCIPtreeGetCurrentNode(), SCIPtreeProbing(), SCIPvarAdjustLb(), SCIPvarGetLbLocal(), SCIPvarGetName(), SCIPwarningMessage(), Scip::set, Scip::stat, Scip::transprob, Scip::tree, and TRUE.

Referenced by applyVboundsFixings(), chgProbingBound(), performFixing(), performRandRounding(), performStrongbranchSOS1(), performStrongbranchWithPropagation(), SCIP_DECL_HEUREXEC(), SCIPapplyProbingVar(), SCIPperformGenericDivingAlgorithm(), tryOneOpt(), and trySolCandidate().

◆ SCIPchgVarUbProbing()

SCIP_EXPORT SCIP_RETCODE SCIPchgVarUbProbing	(	SCIP *	scip,
		SCIP_VAR *	var,
		SCIP_Real	newbound
	)

injects a change of variable's upper bound into current probing node; the same can also be achieved with a call to SCIPchgVarUb(), but in this case, the bound change would be treated like a deduction instead of a branching decision

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:

Parameters

scip	SCIP data structure
var	variable to change the bound for
newbound	new value for bound

Definition at line 335 of file scip_probing.c.

References Scip::branchcand, Scip::cliquetable, Scip::eventqueue, FALSE, Scip::lp, Scip::mem, Scip::origprob, SCIP_Mem::probmem, Scip::reopt, SCIP_BOUNDTYPE_UPPER, SCIP_CALL, SCIP_INVALIDCALL, SCIP_NODETYPE_PROBINGNODE, SCIP_OKAY, SCIP_STAGE_SOLVING, SCIPcheckStage(), SCIPerrorMessage, SCIPgetStage(), SCIPisInfinity(), SCIPnodeAddBoundchg(), SCIPnodeGetType(), SCIPtreeGetCurrentNode(), SCIPtreeProbing(), SCIPvarAdjustUb(), SCIPvarGetName(), SCIPvarGetUbLocal(), SCIPwarningMessage(), Scip::set, Scip::stat, Scip::transprob, Scip::tree, and TRUE.

Referenced by applyVboundsFixings(), chgProbingBound(), performFixing(), performRandRounding(), performStrongbranchSOS1(), performStrongbranchWithPropagation(), SCIP_DECL_HEUREXEC(), SCIPapplyProbingVar(), SCIPperformGenericDivingAlgorithm(), tryOneOpt(), and trySolCandidate().

◆ SCIPgetVarObjProbing()

SCIP_EXPORT SCIP_Real SCIPgetVarObjProbing	(	SCIP *	scip,
		SCIP_VAR *	var
	)

gets variable's objective value in current probing

Returns: the variable's objective value in current probing.

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 get the bound for

Definition at line 378 of file scip_probing.c.

References FALSE, NULL, SCIP_CALL_ABORT, SCIP_INVALID, SCIPcheckStage(), SCIPerrorMessage, SCIPtreeProbing(), SCIPvarGetObjLP(), Scip::tree, and TRUE.

Referenced by filterExistingLP(), and SCIPpropagateProbing().

◆ SCIPfixVarProbing()

SCIP_EXPORT SCIP_RETCODE SCIPfixVarProbing	(	SCIP *	scip,
		SCIP_VAR *	var,
		SCIP_Real	fixedval
	)

injects a change of variable's bounds into current probing node to fix the variable to the specified value; the same can also be achieved with a call to SCIPfixVar(), but in this case, the bound changes would be treated like deductions instead of branching decisions

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:

Parameters

scip	SCIP data structure
var	variable to change the bound for
fixedval	value to fix variable to

Definition at line 408 of file scip_probing.c.

References Scip::branchcand, Scip::cliquetable, Scip::eventqueue, FALSE, Scip::lp, Scip::mem, Scip::origprob, SCIP_Mem::probmem, Scip::reopt, SCIP_BOUNDTYPE_LOWER, SCIP_BOUNDTYPE_UPPER, SCIP_CALL, SCIP_INVALIDCALL, SCIP_NODETYPE_PROBINGNODE, SCIP_OKAY, SCIP_Real, SCIPcheckStage(), SCIPerrorMessage, SCIPnodeAddBoundchg(), SCIPnodeGetType(), SCIPsetIsEQ(), SCIPsetIsGT(), SCIPsetIsLT(), SCIPtreeGetCurrentNode(), SCIPtreeProbing(), SCIPvarAdjustLb(), SCIPvarAdjustUb(), SCIPvarGetLbLocal(), SCIPvarGetUbLocal(), Scip::set, Scip::stat, Scip::transprob, Scip::tree, and TRUE.

Referenced by applyBoundHeur(), applyCliqueFixings(), applyOptcumulativeFixings(), applyVboundsFixings(), chgProbingBound(), fixVariable(), performStrongbranchSOS1(), propagateCons(), SCIP_DECL_HEUREXEC(), and SCIPapplyLockFixings().

◆ SCIPchgVarObjProbing()

SCIP_EXPORT SCIP_RETCODE SCIPchgVarObjProbing	(	SCIP *	scip,
		SCIP_VAR *	var,
		SCIP_Real	newobj
	)

changes (column) variable's objective value during probing mode

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:

The variable needs to be a column variable.

Parameters

scip	SCIP data structure
var	variable to change the objective for
newobj	new objective function value

Definition at line 464 of file scip_probing.c.

References SCIP_Lp::cutoffbound, SCIP_Node::data, Scip::eventqueue, FALSE, Scip::lp, Scip::mem, SCIP_Probingnode::nchgdobjs, SCIP_Probingnode::origobjvals, SCIP_Probingnode::origobjvars, Scip::primal, SCIP_Node::probingnode, SCIP_Tree::probingsumchgdobjs, SCIP_Mem::probmem, SCIP_CALL, SCIP_INVALIDCALL, SCIP_NODETYPE_PROBINGNODE, SCIP_OKAY, SCIP_Real, SCIPallocMemoryArray, SCIPcheckStage(), SCIPerrorMessage, SCIPisEQ(), SCIPisInfinity(), SCIPlpDivingObjChanged(), SCIPlpMarkDivingObjChanged(), SCIPlpSetCutoffbound(), SCIPnodeGetType(), SCIPreallocMemoryArray, SCIPsetInfinity(), SCIPtreeGetCurrentNode(), SCIPtreeMarkProbingObjChanged(), SCIPtreeProbing(), SCIPtreeProbingObjChanged(), SCIPvarChgObj(), SCIPvarGetObj(), Scip::set, Scip::transprob, Scip::tree, and TRUE.

Referenced by filterExistingLP(), solveBilinearLP(), and updateSubproblemLowerbound().

◆ SCIPisObjChangedProbing()

SCIP_EXPORT SCIP_Bool SCIPisObjChangedProbing ( SCIP * scip )

returns whether the objective function has changed during probing mode

Returns: TRUE if objective has changed, FALSE otherwise

Precondition

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

Parameters

scip	SCIP data structure

Definition at line 542 of file scip_probing.c.

References FALSE, NULL, SCIP_CALL_ABORT, SCIPcheckStage(), SCIPinProbing(), SCIPtreeProbingObjChanged(), Scip::tree, and TRUE.

◆ SCIPpropagateProbing()

SCIP_EXPORT SCIP_RETCODE SCIPpropagateProbing	(	SCIP *	scip,
		int	maxproprounds,
		SCIP_Bool *	cutoff,
		SCIP_Longint *	ndomredsfound
	)

applies domain propagation on the probing sub problem, that was changed after SCIPstartProbing() was called; the propagated domains of the variables can be accessed with the usual bound accessing calls SCIPvarGetLbLocal() and SCIPvarGetUbLocal(); the propagation is only valid locally, i.e. the local bounds as well as the changed bounds due to SCIPchgVarLbProbing(), SCIPchgVarUbProbing(), and SCIPfixVarProbing() are used for propagation

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:

Parameters

scip	SCIP data structure
maxproprounds	maximal number of propagation rounds (-1: no limit, 0: parameter settings)
cutoff	pointer to store whether the probing node can be cut off
ndomredsfound	pointer to store the number of domain reductions found, or NULL

Definition at line 565 of file scip_probing.c.

References Scip::branchcand, Scip::cliquetable, Scip::conflict, Scip::eventqueue, FALSE, Scip::lp, Scip::mem, MIN, SCIP_Stat::nprobboundchgs, SCIP_Stat::nprobholechgs, NULL, Scip::origprob, Scip::primal, SCIP_Tree::probingobjchanged, SCIP_Tree::probingsumchgdobjs, SCIP_Mem::probmem, Scip::reopt, SCIP_Bool, SCIP_CALL, SCIP_INVALIDCALL, SCIP_OKAY, SCIP_PROPTIMING_ALWAYS, SCIP_Real, SCIPallocBufferArray, SCIPcheckStage(), SCIPerrorMessage, SCIPfreeBufferArray, SCIPgetDepth(), SCIPgetNVars(), SCIPgetVarObjProbing(), SCIPgetVars(), SCIPisEQ(), SCIPlpMarkDivingObjChanged(), SCIPlpUnmarkDivingObjChanged(), SCIPpropagateDomains(), SCIPtreeProbing(), SCIPvarChgObj(), Scip::set, Scip::stat, Scip::transprob, Scip::tree, TRUE, and SCIP_Var::unchangedobj.

Referenced by applyBoundHeur(), applyCliqueFixings(), applyOptcumulativeFixings(), applyVboundsFixings(), executeStrongBranching(), performFixing(), performRandRounding(), performStrongbranchSOS1(), performStrongbranchWithPropagation(), propagateCons(), SCIP_DECL_HEUREXEC(), SCIPapplyLockFixings(), SCIPapplyProbingVar(), SCIPperformGenericDivingAlgorithm(), tightenVariables(), tryOneOpt(), and trySolCandidate().

◆ SCIPpropagateProbingImplications()

SCIP_EXPORT SCIP_RETCODE SCIPpropagateProbingImplications	(	SCIP *	scip,
		SCIP_Bool *	cutoff
	)

applies domain propagation on the probing sub problem, that was changed after SCIPstartProbing() was called; only propagations of the binary variables fixed at the current probing node that are triggered by the implication graph and the clique table are applied; the propagated domains of the variables can be accessed with the usual bound accessing calls SCIPvarGetLbLocal() and SCIPvarGetUbLocal(); the propagation is only valid locally, i.e. the local bounds as well as the changed bounds due to SCIPchgVarLbProbing(), SCIPchgVarUbProbing(), and SCIPfixVarProbing() are used for propagation

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:

Parameters

scip	SCIP data structure
cutoff	pointer to store whether the probing node can be cut off

Definition at line 671 of file scip_probing.c.

References Scip::branchcand, Scip::cliquetable, Scip::eventqueue, FALSE, Scip::lp, Scip::mem, Scip::origprob, SCIP_Mem::probmem, Scip::reopt, SCIP_CALL, SCIP_INVALIDCALL, SCIP_OKAY, SCIPcheckStage(), SCIPerrorMessage, SCIPnodePropagateImplics(), SCIPtreeGetCurrentNode(), SCIPtreeProbing(), Scip::set, Scip::stat, Scip::transprob, Scip::tree, and TRUE.

Referenced by SCIPapplyProbingVar().

◆ SCIPsolveProbingLP()

SCIP_EXPORT SCIP_RETCODE SCIPsolveProbingLP	(	SCIP *	scip,
		int	itlim,
		SCIP_Bool *	lperror,
		SCIP_Bool *	cutoff
	)

solves the LP at the current probing node (cannot be applied at preprocessing stage); no separation or pricing is applied

The LP has to be constructed before (you can use SCIPisLPConstructed() or SCIPconstructLP()).

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

Parameters

scip	SCIP data structure
itlim	maximal number of LP iterations to perform, or -1 for no limit
lperror	pointer to store whether an unresolved LP error occurred
cutoff	pointer to store whether the probing LP was infeasible or the objective limit was reached (or NULL, if not needed)

Definition at line 801 of file scip_probing.c.

References FALSE, SCIP_CALL, SCIP_OKAY, SCIPcheckStage(), solveProbingLP(), and TRUE.

Referenced by applyBoundHeur(), applyVbounds(), performStrongbranchSOS1(), performStrongbranchWithPropagation(), polishSolution(), SCIP_DECL_HEUREXEC(), SCIPbendersComputeSubproblemLowerbound(), SCIPbendersSolveSubproblemLP(), selectVarMultAggrBranching(), solveBilinearLP(), solveLP(), tryOneOpt(), trySolCandidate(), and updateSubproblemLowerbound().

◆ SCIPsolveProbingLPWithPricing()

SCIP_EXPORT SCIP_RETCODE SCIPsolveProbingLPWithPricing	(	SCIP *	scip,
		SCIP_Bool	pretendroot,
		SCIP_Bool	displayinfo,
		int	maxpricerounds,
		SCIP_Bool *	lperror,
		SCIP_Bool *	cutoff
	)

solves the LP at the current probing node (cannot be applied at preprocessing stage) and applies pricing until the LP is solved to optimality; no separation is applied

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

solves the LP at the current probing node (cannot be applied at preprocessing stage) and applies pricing until the LP is solved to optimality; no separation is applied

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

Parameters

scip	SCIP data structure
pretendroot	should the pricers be called as if we were at the root node?
displayinfo	should info lines be displayed after each pricing round?
maxpricerounds	maximal number of pricing rounds (-1: no limit); a finite limit means that the LP might not be solved to optimality!
lperror	pointer to store whether an unresolved LP error occurred
cutoff	pointer to store whether the probing LP was infeasible or the objective limit was reached (or NULL, if not needed)

Definition at line 825 of file scip_probing.c.

References FALSE, SCIP_CALL, SCIP_OKAY, SCIPcheckStage(), solveProbingLP(), and TRUE.

Referenced by executeStrongBranching().

◆ SCIPsetProbingLPState()

SCIP_EXPORT SCIP_RETCODE SCIPsetProbingLPState	(	SCIP *	scip,
		SCIP_LPISTATE **	lpistate,
		SCIP_LPINORMS **	lpinorms,
		SCIP_Bool	primalfeas,
		SCIP_Bool	dualfeas
	)

sets the LP state for the current probing node

Note: state and norms are stored at the node and later released by SCIP; therefore, the pointers are set to NULL by the method; the pointers to state and norms must not be NULL; however, they may point to a NULL pointer if the respective information should not be set

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:

Parameters

scip	SCIP data structure
lpistate	pointer to LP state information (like basis information)
lpinorms	pointer to LP pricing norms information
primalfeas	primal feasibility when LP state information was stored
dualfeas	dual feasibility when LP state information was stored

Definition at line 858 of file scip_probing.c.

References FALSE, Scip::lp, Scip::mem, SCIP_Mem::probmem, SCIP_CALL, SCIP_INVALIDCALL, SCIP_OKAY, SCIPcheckStage(), SCIPerrorMessage, SCIPtreeProbing(), SCIPtreeSetProbingLPState(), Scip::tree, and TRUE.

◆ SCIPaddRowProbing()

SCIP_EXPORT SCIP_RETCODE SCIPaddRowProbing	(	SCIP *	scip,
		SCIP_ROW *	row
	)

adds a row to the LP in the current probing 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
row	row to be added

Definition at line 889 of file scip_probing.c.

References Scip::eventfilter, Scip::eventqueue, FALSE, Scip::lp, Scip::mem, NULL, SCIP_Mem::probmem, SCIP_CALL, SCIP_INVALIDCALL, SCIP_OKAY, SCIPcheckStage(), SCIPerrorMessage, SCIPlpAddRow(), SCIPnodeGetDepth(), SCIPtreeGetCurrentNode(), SCIPtreeProbing(), Scip::set, Scip::tree, and TRUE.

Referenced by solveBilinearLP().

◆ SCIPapplyCutsProbing()

SCIP_EXPORT SCIP_RETCODE SCIPapplyCutsProbing	(	SCIP *	scip,
		SCIP_Bool *	cutoff
	)

applies the cuts in the separation storage to the LP and clears the storage afterwards; this method can only be applied during probing; the user should resolve the probing LP afterwards in order to get a new solution

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

Parameters

scip	SCIP data structure
cutoff	pointer to store whether an empty domain was created

Definition at line 929 of file scip_probing.c.

References Scip::branchcand, Scip::cliquetable, Scip::eventfilter, Scip::eventqueue, FALSE, Scip::lp, Scip::mem, Scip::origprob, SCIP_Mem::probmem, Scip::reopt, SCIP_CALL, SCIP_EFFICIACYCHOICE_LP, SCIP_INVALIDCALL, SCIP_OKAY, SCIPcheckStage(), SCIPerrorMessage, SCIPsepastoreApplyCuts(), SCIPtreeProbing(), Scip::sepastore, Scip::set, Scip::stat, Scip::transprob, Scip::tree, and TRUE.

◆ SCIPsolveProbingRelax()

SCIP_EXPORT SCIP_RETCODE SCIPsolveProbingRelax	(	SCIP *	scip,
		SCIP_Bool *	cutoff
	)

solves relaxation(s) at the current probing node (cannot be applied at preprocessing stage); no separation or pricing is applied

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

Parameters

scip	SCIP data structure
cutoff	pointer to store whether a relaxation was infeasible or the objective limit was reached (or NULL, if not needed)

Definition at line 958 of file scip_probing.c.

References FALSE, NULL, r, SCIP_CALL, SCIP_CONSADDED, SCIP_CUTOFF, SCIP_DIDNOTRUN, SCIP_INVALIDCALL, SCIP_INVALIDRESULT, SCIP_OKAY, SCIP_Real, SCIP_REDUCEDDOM, SCIP_SEPARATED, SCIP_SUCCESS, SCIP_SUSPENDED, SCIPcheckStage(), SCIPdebugMsg, SCIPerrorMessage, SCIPinfinity(), SCIPrelaxExec(), SCIPrelaxGetName(), SCIPsetSortRelaxs(), SCIPtreeGetCurrentDepth(), SCIPtreeProbing(), Scip::set, Scip::stat, Scip::tree, and TRUE.

◆ SCIPgetDivesetScore()

SCIP_EXPORT SCIP_RETCODE SCIPgetDivesetScore	(	SCIP *	scip,
		SCIP_DIVESET *	diveset,
		SCIP_DIVETYPE	divetype,
		SCIP_VAR *	divecand,
		SCIP_Real	divecandsol,
		SCIP_Real	divecandfrac,
		SCIP_Real *	candscore,
		SCIP_Bool *	roundup
	)

stores the candidate score and preferred rounding direction for a candidate variable

gets the candidate score and preferred rounding direction for a candidate variable

Parameters

scip	SCIP data structure
diveset	general diving settings
divetype	represents different methods for a dive set to explore the next children
divecand	the candidate for which the branching direction is requested
divecandsol	LP solution value of the candidate
divecandfrac	fractionality of the candidate
candscore	pointer to store the candidate score
roundup	pointer to store whether preferred direction for diving is upwards

Definition at line 1026 of file scip_probing.c.

References FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIPcheckStage(), SCIPdivesetGetScore(), Scip::set, and TRUE.

Referenced by getDiveBdChgsSOS1conflictgraph(), getDiveBdChgsSOS1constraints(), SCIP_DECL_CONSGETDIVEBDCHGS(), and selectNextDiving().

◆ SCIPupdateDivesetLPStats()

SCIP_EXPORT void SCIPupdateDivesetLPStats	(	SCIP *	scip,
		SCIP_DIVESET *	diveset,
		SCIP_Longint	niterstoadd
	)

update diveset LP statistics, should be called after every LP solved by this diving heuristic

Parameters

scip	SCIP data structure
diveset	diving settings
niterstoadd	additional number of LP iterations to be added

Definition at line 1051 of file scip_probing.c.

References NULL, SCIPdivesetUpdateLPStats(), and Scip::stat.

Referenced by solveLP().

◆ SCIPupdateDivesetStats()

SCIP_EXPORT void SCIPupdateDivesetStats	(	SCIP *	scip,
		SCIP_DIVESET *	diveset,
		int	nprobingnodes,
		int	nbacktracks,
		SCIP_Longint	nsolsfound,
		SCIP_Longint	nbestsolsfound,
		SCIP_Longint	nconflictsfound,
		SCIP_Bool	leavewassol
	)

update diveset statistics and global diveset statistics

Parameters

scip	SCIP data structure
diveset	diveset to be reset
nprobingnodes	the number of probing nodes explored this time
nbacktracks	the number of backtracks during probing this time
nsolsfound	the number of solutions found
nbestsolsfound	the number of best solutions found
nconflictsfound	number of new conflicts found this time
leavewassol	was a solution found at the leaf?

Definition at line 1064 of file scip_probing.c.

References NULL, SCIPdivesetUpdateStats(), SCIPgetDepth(), SCIPinProbing(), and Scip::stat.

Referenced by SCIPperformGenericDivingAlgorithm().

◆ SCIPgetDiveBoundChanges()

SCIP_EXPORT SCIP_RETCODE SCIPgetDiveBoundChanges	(	SCIP *	scip,
		SCIP_DIVESET *	diveset,
		SCIP_SOL *	sol,
		SCIP_Bool *	success,
		SCIP_Bool *	infeasible
	)

enforces a probing/diving solution by suggesting bound changes that maximize the score w.r.t. the current diving settings

the process is guided by the enforcement priorities of the constraint handlers and the scoring mechanism provided by the dive set. Constraint handlers may suggest diving bound changes in decreasing order of their enforcement priority, based on the solution values in the solution sol and the current local bounds of the variables. A diving bound change is a triple (variable,branching direction,value) and is used inside SCIPperformGenericDivingAlgorithm().

After a successful call, SCIP holds two arrays of suggested dive bound changes, one for the preferred child and one for the alternative.

See also: SCIPgetDiveBoundChangeData() for retrieving the dive bound change suggestions.

The method stops after the first constraint handler was successful

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
diveset	diving settings to control scoring
sol	current solution of diving mode
success	pointer to store whether constraint handler successfully found a variable
infeasible	pointer to store whether the current node was detected to be infeasible

Definition at line 1106 of file scip_probing.c.

References SCIP_Set::conshdlrs_enfo, FALSE, SCIP_Set::nconshdlrs, NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPcheckStage(), SCIPclearDiveBoundChanges(), SCIPconshdlrGetDiveBoundChanges(), SCIPinProbing(), SCIPtreeGetDiveBoundChangeData(), Scip::set, Scip::tree, and TRUE.

Referenced by selectNextDiving().

◆ SCIPaddDiveBoundChange()

SCIP_EXPORT SCIP_RETCODE SCIPaddDiveBoundChange	(	SCIP *	scip,
		SCIP_VAR *	var,
		SCIP_BRANCHDIR	dir,
		SCIP_Real	value,
		SCIP_Bool	preferred
	)

adds a diving bound change to the diving bound change storage of SCIP together with the information if this is a bound change for the preferred direction or not

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 apply the bound change to
dir	direction of the bound change
value	value to adjust this variable bound to
preferred	is this a bound change for the preferred child?

Definition at line 1168 of file scip_probing.c.

References FALSE, Scip::mem, NULL, SCIP_Mem::probmem, SCIP_CALL, SCIP_OKAY, SCIPcheckStage(), SCIPinProbing(), SCIPtreeAddDiveBoundChange(), Scip::tree, and TRUE.

Referenced by getDiveBdChgsSOS1conflictgraph(), getDiveBdChgsSOS1constraints(), SCIP_DECL_CONSGETDIVEBDCHGS(), and selectNextDiving().

◆ SCIPgetDiveBoundChangeData()

SCIP_EXPORT void SCIPgetDiveBoundChangeData	(	SCIP *	scip,
		SCIP_VAR ***	variables,
		SCIP_BRANCHDIR **	directions,
		SCIP_Real **	values,
		int *	ndivebdchgs,
		SCIP_Bool	preferred
	)

get the dive bound change data for the preferred or the alternative direction

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
variables	pointer to store variables for the specified direction
directions	pointer to store the branching directions
values	pointer to store bound change values
ndivebdchgs	pointer to store the number of dive bound changes
preferred	should the dive bound changes for the preferred child be output?

Definition at line 1194 of file scip_probing.c.

References FALSE, NULL, SCIP_CALL_ABORT, SCIPcheckStage(), SCIPinProbing(), SCIPtreeGetDiveBoundChangeData(), Scip::tree, and TRUE.

Referenced by SCIPperformGenericDivingAlgorithm().

◆ SCIPclearDiveBoundChanges()

SCIP_EXPORT void SCIPclearDiveBoundChanges ( SCIP * scip )

clear the dive bound change data structures

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 1221 of file scip_probing.c.

References FALSE, NULL, SCIP_CALL_ABORT, SCIPcheckStage(), SCIPtreeClearDiveBoundChanges(), Scip::tree, and TRUE.

Referenced by SCIPgetDiveBoundChanges(), and selectNextDiving().

SCIP

Detailed Description

Functions

Function Documentation

◆ SCIPinProbing()

◆ SCIPstartProbing()

◆ SCIPnewProbingNode()

◆ SCIPgetProbingDepth()

◆ SCIPbacktrackProbing()

◆ SCIPendProbing()

◆ SCIPchgVarLbProbing()

◆ SCIPchgVarUbProbing()

◆ SCIPgetVarObjProbing()

◆ SCIPfixVarProbing()

◆ SCIPchgVarObjProbing()

◆ SCIPisObjChangedProbing()

◆ SCIPpropagateProbing()

◆ SCIPpropagateProbingImplications()

◆ SCIPsolveProbingLP()

◆ SCIPsolveProbingLPWithPricing()

◆ SCIPsetProbingLPState()

◆ SCIPaddRowProbing()

◆ SCIPapplyCutsProbing()

◆ SCIPsolveProbingRelax()

◆ SCIPgetDivesetScore()

◆ SCIPupdateDivesetLPStats()

◆ SCIPupdateDivesetStats()

◆ SCIPgetDiveBoundChanges()

◆ SCIPaddDiveBoundChange()

◆ SCIPgetDiveBoundChangeData()

◆ SCIPclearDiveBoundChanges()