Exact Solving Mode

Detailed Description

general methods for numerically exact solving

Functions
SCIP_RETCODE	SCIPenableExactSolving (SCIP *scip, SCIP_Bool enable)
SCIP_Bool	SCIPisExact (SCIP *scip)
SCIP_Bool	SCIPallowNegSlack (SCIP *scip)
SCIP_RETCODE	SCIPbranchLPExact (SCIP *scip, SCIP_RESULT *result)
SCIP_RETCODE	SCIPaddRowExact (SCIP *scip, SCIP_ROWEXACT *rowexact)

Function Documentation

SCIPenableExactSolving()

SCIP_RETCODE SCIPenableExactSolving	(	SCIP *	scip,
		SCIP_Bool	enable
	)

enables or disables exact solving 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:

• SCIP_STAGE_INIT

Parameters

scip	SCIP data structure
enable	enable exact solving (TRUE) or disable it (FALSE)

Definition at line 151 of file scip_exact.c.

References NULL, SCIP_ERROR, SCIP_INVALIDCALL, SCIP_OKAY, SCIP_STAGE_PROBLEM, SCIPerrorMessage, and SCIPgetStage().

Referenced by applyRepair(), createSubscip(), createSubSCIP(), doCopy(), SCIPcopyLargeNeighborhoodSearch(), and setupSubscipLpface().

SCIPisExact()

SCIP_Bool SCIPisExact

(

SCIP *

scip

)

returns whether the solution process is arithmetically exact, i.e., not subject to roundoff errors

Returns

Returns TRUE if SCIP is in exact solving mode, otherwise FALSE

returns whether the solution process should be probably correct

Returns

Returns TRUE if SCIP is in exact solving mode, otherwise FALSE

Parameters

scip	SCIP data structure

Definition at line 193 of file scip_exact.c.

References NULL.

Referenced by addCut(), addOneRowSafely(), analyzeStrongbranch(), applyRepair(), branch(), branchOnVar(), calcActivityBounds(), calcMIRSafely(), checkSolOrig(), checkSolOrigExact(), chgCoeffWithBoundSafely(), copyVars(), createVariable(), cutsRoundMIRSafely(), cutsSubstituteMIR(), cutsSubstituteMIRSafely(), cutsTransformMIRSafely(), cutTightenCoefs(), cutTightenCoefsSafely(), determineTotalNumberLinearConss(), execRelpscost(), freeSolve(), fromCommandLine(), getFixedVariable(), getObjectiveRow(), getVariable(), initializeCandsLists(), initSolve(), performBoundSubstitution(), performBoundSubstitutionSafely(), performBoundSubstitutionSimple(), performBoundSubstitutionSimpleSafely(), postprocessCutSafely(), presolve(), presolveRound(), readBinaries(), readBounds(), readColsExact(), readConstraints(), readIndicators(), readMpsExact(), readObjective(), readOPBFile(), readQCMatrix(), readQMatrix(), readSol(), readSolFile(), readSOS(), readXmlSolFile(), removeExactConflictFromCertificateHashmap(), removeZerosSafely(), runVanillaStrongBranching(), scaleValSafely(), SCIP_DECL_BRANCHEXECLP(), SCIP_DECL_CONSCHECK(), SCIP_DECL_CONSDEACTIVE(), SCIP_DECL_CONSDELETE(), SCIP_DECL_CONSDELVARS(), SCIP_DECL_CONSENFOLP(), SCIP_DECL_CONSENFOPS(), SCIP_DECL_CONSENFORELAX(), SCIP_DECL_CONSEXIT(), SCIP_DECL_CONSEXITPRE(), SCIP_DECL_CONSEXITSOL(), SCIP_DECL_CONSINIT(), SCIP_DECL_CONSINITLP(), SCIP_DECL_CONSLOCK(), SCIP_DECL_CONSPROP(), SCIP_DECL_CONSSEPALP(), SCIP_DECL_CONSSEPASOL(), SCIP_DECL_CONSTRANS(), SCIP_DECL_DIALOGEXEC(), SCIP_DECL_EVENTEXEC(), SCIP_DECL_HEUREXEC(), SCIP_DECL_PROPEXEC(), SCIP_DECL_READERREAD(), SCIP_DECL_READERWRITE(), SCIP_DECL_SEPAEXECLP(), SCIPaddCons(), SCIPaddConsNode(), SCIPaddOrigObjoffset(), SCIPaddVar(), SCIPaggrRowAddRowSafely(), SCIPaggrRowRemoveZeros(), SCIPaggrRowSumRows(), SCIPallowNegSlack(), SCIPcalcMIR(), SCIPcertificateFreeRowInfo(), SCIPcertifyMirCut(), SCIPcheckSol(), SCIPcheckSolOrig(), SCIPcollectSolutionStatistics(), SCIPcopyConsExactLinear(), SCIPendDive(), SCIPfixVarExact(), SCIPfreeCertificateActiveAggrInfo(), SCIPfreeCertificateActiveMirInfo(), SCIPgetOrigObjoffsetExact(), SCIPincludeBranchruleRelpscost(), SCIPmatrixCreate(), SCIPmatrixFree(), SCIPprintSol(), SCIPprintSolutionStatistics(), SCIPprocessShellArguments(), SCIPpropagateProbing(), SCIPreadMps(), SCIPselectVarPseudoStrongBranching(), SCIPselectVarStrongBranching(), SCIPsolve(), SCIPsolveCIP(), SCIPsolveConcurrent(), SCIPstoreCertificateActiveAggrInfo(), SCIPstoreCertificateActiveMirInfo(), SCIPtightenVarLbExact(), SCIPtightenVarLbGlobal(), SCIPtightenVarUbExact(), SCIPtightenVarUbGlobal(), SCIPtransformProb(), SCIPvalidateSolveExact(), SCIPwriteLp(), SCIPwriteMps(), selectVarMultAggrBranching(), setColumnMajorFormat(), setObjective(), setupAndSolveSubscip(), setupProbingSCIP(), setupSCIPparamsStage3(), setupSubscipLpface(), solveLp(), varVecAddScaledRowCoefsSafely(), writeOpbConstraints(), and writeOpbObjective().

SCIPallowNegSlack()

SCIP_Bool SCIPallowNegSlack

(

SCIP *

scip

)

returns whether aggregation is allowed to use negative slack in exact solving mode

Returns

Returns TRUE if SCIP is not in exact solving mode or aggregation is allowed to use negative slack

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 212 of file scip_exact.c.

References FALSE, NULL, SCIP_CALL_ABORT, SCIPcheckStage, SCIPisExact(), and TRUE.

Referenced by SCIP_DECL_SEPAEXECLP().

SCIPbranchLPExact()

SCIP_RETCODE SCIPbranchLPExact	(	SCIP *	scip,
		SCIP_RESULT *	result
	)

branches on an LP solution exactly; does not call branching rules, since fractionalities are assumed to small; if no fractional 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 235 of file scip_exact.c.

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

Referenced by SCIP_DECL_CONSENFOLP().

SCIPaddRowExact()

SCIP_RETCODE SCIPaddRowExact	(	SCIP *	scip,
		SCIP_ROWEXACT *	rowexact
	)

adds row to exact separation storage

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
rowexact	exact row to add

Definition at line 257 of file scip_exact.c.

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

Referenced by addRelaxation(), and SCIPsepastoreApplyCuts().