Presolver

Detailed Description

methods for presolver plugins

Modules
	Special Methods
	methods commonly used for presolving

Functions
	SCIP_DECL_SORTPTRCOMP (SCIPpresolComp)
	SCIP_DECL_SORTPTRCOMP (SCIPpresolCompName)
SCIP_PRESOLDATA *	SCIPpresolGetData (SCIP_PRESOL *presol)
void	SCIPpresolSetData (SCIP_PRESOL *presol, SCIP_PRESOLDATA *presoldata)
const char *	SCIPpresolGetName (SCIP_PRESOL *presol)
const char *	SCIPpresolGetDesc (SCIP_PRESOL *presol)
int	SCIPpresolGetPriority (SCIP_PRESOL *presol)
int	SCIPpresolGetMaxrounds (SCIP_PRESOL *presol)
SCIP_PRESOLTIMING	SCIPpresolGetTiming (SCIP_PRESOL *presol)
void	SCIPpresolSetTiming (SCIP_PRESOL *presol, SCIP_PRESOLTIMING timing)
SCIP_Bool	SCIPpresolIsInitialized (SCIP_PRESOL *presol)
SCIP_Real	SCIPpresolGetSetupTime (SCIP_PRESOL *presol)
SCIP_Real	SCIPpresolGetTime (SCIP_PRESOL *presol)
int	SCIPpresolGetNFixedVars (SCIP_PRESOL *presol)
int	SCIPpresolGetNAggrVars (SCIP_PRESOL *presol)
int	SCIPpresolGetNChgVarTypes (SCIP_PRESOL *presol)
int	SCIPpresolGetNChgBds (SCIP_PRESOL *presol)
int	SCIPpresolGetNAddHoles (SCIP_PRESOL *presol)
int	SCIPpresolGetNDelConss (SCIP_PRESOL *presol)
int	SCIPpresolGetNAddConss (SCIP_PRESOL *presol)
int	SCIPpresolGetNUpgdConss (SCIP_PRESOL *presol)
int	SCIPpresolGetNChgCoefs (SCIP_PRESOL *presol)
int	SCIPpresolGetNChgSides (SCIP_PRESOL *presol)
int	SCIPpresolGetNCalls (SCIP_PRESOL *presol)
SCIP_RETCODE	SCIPincludePresol (SCIP *scip, const char *name, const char *desc, int priority, int maxrounds, SCIP_PRESOLTIMING timing, SCIP_DECL_PRESOLCOPY((*presolcopy)), SCIP_DECL_PRESOLFREE((*presolfree)), SCIP_DECL_PRESOLINIT((*presolinit)), SCIP_DECL_PRESOLEXIT((*presolexit)), SCIP_DECL_PRESOLINITPRE((*presolinitpre)), SCIP_DECL_PRESOLEXITPRE((*presolexitpre)), SCIP_DECL_PRESOLEXEC((*presolexec)), SCIP_PRESOLDATA *presoldata)
SCIP_RETCODE	SCIPincludePresolBasic (SCIP *scip, SCIP_PRESOL **presolptr, const char *name, const char *desc, int priority, int maxrounds, SCIP_PRESOLTIMING timing, SCIP_DECL_PRESOLEXEC((*presolexec)), SCIP_PRESOLDATA *presoldata)
SCIP_RETCODE	SCIPsetPresolCopy (SCIP *scip, SCIP_PRESOL *presol, SCIP_DECL_PRESOLCOPY((*presolcopy)))
SCIP_RETCODE	SCIPsetPresolFree (SCIP *scip, SCIP_PRESOL *presol, SCIP_DECL_PRESOLFREE((*presolfree)))
SCIP_RETCODE	SCIPsetPresolInit (SCIP *scip, SCIP_PRESOL *presol, SCIP_DECL_PRESOLINIT((*presolinit)))
SCIP_RETCODE	SCIPsetPresolExit (SCIP *scip, SCIP_PRESOL *presol, SCIP_DECL_PRESOLEXIT((*presolexit)))
SCIP_RETCODE	SCIPsetPresolInitpre (SCIP *scip, SCIP_PRESOL *presol, SCIP_DECL_PRESOLINITPRE((*presolinitpre)))
SCIP_RETCODE	SCIPsetPresolExitpre (SCIP *scip, SCIP_PRESOL *presol, SCIP_DECL_PRESOLEXITPRE((*presolexitpre)))
SCIP_PRESOL *	SCIPfindPresol (SCIP *scip, const char *name)
SCIP_PRESOL **	SCIPgetPresols (SCIP *scip)
int	SCIPgetNPresols (SCIP *scip)
SCIP_RETCODE	SCIPsetPresolPriority (SCIP *scip, SCIP_PRESOL *presol, int priority)

Function Documentation

SCIP_DECL_SORTPTRCOMP() [1/2]

SCIP_DECL_SORTPTRCOMP

(

SCIPpresolComp

)

compares two presolvers w. r. to their priority

Definition at line 47 of file presol.c.

SCIP_DECL_SORTPTRCOMP() [2/2]

SCIP_DECL_SORTPTRCOMP

(

SCIPpresolCompName

)

comparison method for sorting presolvers w.r.t. to their name

Definition at line 53 of file presol.c.

References SCIPpresolGetName().

SCIPpresolGetData()

SCIP_PRESOLDATA* SCIPpresolGetData

(

SCIP_PRESOL *

presol

)

gets user data of presolver

Parameters

presol

presolver

Definition at line 466 of file presol.c.

References NULL, and SCIP_Presol::presoldata.

Referenced by SCIP_DECL_PRESOLCOPY(), SCIP_DECL_PRESOLEXEC(), SCIP_DECL_PRESOLEXIT(), SCIP_DECL_PRESOLEXITPRE(), SCIP_DECL_PRESOLFREE(), SCIP_DECL_PRESOLINIT(), SCIP_DECL_PRESOLINITPRE(), SCIPfindObjPresol(), and SCIPgetObjPresol().

SCIPpresolSetData()

void SCIPpresolSetData	(	SCIP_PRESOL *	presol,
		SCIP_PRESOLDATA *	presoldata
	)

sets user data of presolver; user has to free old data in advance!

Parameters

presol	presolver
presoldata	new presolver user data

Definition at line 476 of file presol.c.

References NULL, and SCIP_Presol::presoldata.

Referenced by SCIP_DECL_PRESOLFREE().

SCIPpresolGetName()

const char* SCIPpresolGetName

(

SCIP_PRESOL *

presol

)

gets name of presolver

Parameters

presol

presolver

Definition at line 553 of file presol.c.

References SCIP_Presol::name, and NULL.

Referenced by paramsetSetPresolvingDefault(), paramsetSetPresolvingOff(), presolveRound(), printPresolverStatistics(), SCIP_DECL_DIALOGEXEC(), SCIP_DECL_PRESOLCOPY(), SCIP_DECL_PRESOLEXEC(), SCIP_DECL_SORTPTRCOMP(), SCIPcopyConcurrentSolvingStats(), SCIPincludeDialogDefaultFix(), SCIPincludeDialogDefaultSet(), SCIPpresolCopyInclude(), and SCIPsetFindConflicthdlr().

SCIPpresolGetDesc()

const char* SCIPpresolGetDesc

(

SCIP_PRESOL *

presol

)

gets description of presolver

Parameters

presol

presolver

Definition at line 563 of file presol.c.

References SCIP_Presol::desc, and NULL.

Referenced by SCIP_DECL_DIALOGEXEC(), SCIPincludeDialogDefaultFix(), and SCIPincludeDialogDefaultSet().

SCIPpresolGetPriority()

int SCIPpresolGetPriority

(

SCIP_PRESOL *

presol

)

gets priority of presolver

Parameters

presol

presolver

Definition at line 573 of file presol.c.

References NULL, and SCIP_Presol::priority.

Referenced by presolveRound(), and SCIP_DECL_DIALOGEXEC().

SCIPpresolGetMaxrounds()

int SCIPpresolGetMaxrounds

(

SCIP_PRESOL *

presol

)

gets round limit of presolver

Parameters

presol

presolver

Definition at line 583 of file presol.c.

References SCIP_Presol::maxrounds, and NULL.

Referenced by SCIP_DECL_DIALOGEXEC().

SCIPpresolGetTiming()

SCIP_PRESOLTIMING SCIPpresolGetTiming

(

SCIP_PRESOL *

presol

)

gets the timing mask of the presolver

Parameters

presol

presolver

Definition at line 607 of file presol.c.

References NULL, and SCIP_Presol::timing.

Referenced by SCIP_DECL_DIALOGEXEC().

SCIPpresolSetTiming()

void SCIPpresolSetTiming	(	SCIP_PRESOL *	presol,
		SCIP_PRESOLTIMING	timing
	)

sets the timing mask of the presolver

Parameters

presol	presolver
timing	timing mask of the presolver

Definition at line 617 of file presol.c.

References NULL, and SCIP_Presol::timing.

SCIPpresolIsInitialized()

SCIP_Bool SCIPpresolIsInitialized

(

SCIP_PRESOL *

presol

)

is presolver initialized?

Parameters

presol

presolver

Definition at line 629 of file presol.c.

References SCIP_Presol::initialized, and NULL.

SCIPpresolGetSetupTime()

SCIP_Real SCIPpresolGetSetupTime

(

SCIP_PRESOL *

presol

)

gets time in seconds used in this presolver for setting up for next stages

Parameters

presol

presolver

Definition at line 651 of file presol.c.

References NULL, SCIPclockGetTime(), and SCIP_Presol::setuptime.

Referenced by printPresolverStatistics().

SCIPpresolGetTime()

SCIP_Real SCIPpresolGetTime

(

SCIP_PRESOL *

presol

)

gets time in seconds used in this presolver

Parameters

presol

presolver

Definition at line 661 of file presol.c.

References NULL, SCIP_Presol::presolclock, and SCIPclockGetTime().

Referenced by printPresolverStatistics().

SCIPpresolGetNFixedVars()

int SCIPpresolGetNFixedVars

(

SCIP_PRESOL *

presol

)

gets number of variables fixed in presolver

Parameters

presol

presolver

Definition at line 671 of file presol.c.

References SCIP_Presol::nfixedvars, and NULL.

Referenced by printPresolverStatistics().

SCIPpresolGetNAggrVars()

int SCIPpresolGetNAggrVars

(

SCIP_PRESOL *

presol

)

gets number of variables aggregated in presolver

Parameters

presol

presolver

Definition at line 681 of file presol.c.

References SCIP_Presol::naggrvars, and NULL.

Referenced by printPresolverStatistics().

SCIPpresolGetNChgVarTypes()

int SCIPpresolGetNChgVarTypes

(

SCIP_PRESOL *

presol

)

gets number of variable types changed in presolver

Parameters

presol

presolver

Definition at line 691 of file presol.c.

References SCIP_Presol::nchgvartypes, and NULL.

Referenced by printPresolverStatistics().

SCIPpresolGetNChgBds()

int SCIPpresolGetNChgBds

(

SCIP_PRESOL *

presol

)

gets number of bounds changed in presolver

Parameters

presol

presolver

Definition at line 701 of file presol.c.

References SCIP_Presol::nchgbds, and NULL.

Referenced by printPresolverStatistics().

SCIPpresolGetNAddHoles()

int SCIPpresolGetNAddHoles

(

SCIP_PRESOL *

presol

)

gets number of holes added to domains of variables in presolver

Parameters

presol

presolver

Definition at line 711 of file presol.c.

References SCIP_Presol::naddholes, and NULL.

Referenced by printPresolverStatistics().

SCIPpresolGetNDelConss()

int SCIPpresolGetNDelConss

(

SCIP_PRESOL *

presol

)

gets number of constraints deleted in presolver

Parameters

presol

presolver

Definition at line 721 of file presol.c.

References SCIP_Presol::ndelconss, and NULL.

Referenced by printPresolverStatistics().

SCIPpresolGetNAddConss()

int SCIPpresolGetNAddConss

(

SCIP_PRESOL *

presol

)

gets number of constraints added in presolver

Parameters

presol

presolver

Definition at line 731 of file presol.c.

References SCIP_Presol::naddconss, and NULL.

Referenced by printPresolverStatistics().

SCIPpresolGetNUpgdConss()

int SCIPpresolGetNUpgdConss

(

SCIP_PRESOL *

presol

)

gets number of constraints upgraded in presolver

Parameters

presol

presolver

Definition at line 741 of file presol.c.

References NULL, and SCIP_Presol::nupgdconss.

SCIPpresolGetNChgCoefs()

int SCIPpresolGetNChgCoefs

(

SCIP_PRESOL *

presol

)

gets number of coefficients changed in presolver

Parameters

presol

presolver

Definition at line 751 of file presol.c.

References SCIP_Presol::nchgcoefs, and NULL.

Referenced by printPresolverStatistics().

SCIPpresolGetNChgSides()

int SCIPpresolGetNChgSides

(

SCIP_PRESOL *

presol

)

gets number of constraint sides changed in presolver

Parameters

presol

presolver

Definition at line 761 of file presol.c.

References SCIP_Presol::nchgsides, and NULL.

Referenced by printPresolverStatistics().

SCIPpresolGetNCalls()

int SCIPpresolGetNCalls

(

SCIP_PRESOL *

presol

)

gets number of times the presolver was called and tried to find reductions

Parameters

presol

presolver

Definition at line 771 of file presol.c.

References SCIP_Presol::ncalls, and NULL.

Referenced by printPresolverStatistics().

SCIPincludePresol()

SCIP_RETCODE SCIPincludePresol	(	SCIP *	scip,
		const char *	name,
		const char *	desc,
		int	priority,
		int	maxrounds,
		SCIP_PRESOLTIMING	timing,
		SCIP_DECL_PRESOLCOPY((*presolcopy))	,
		SCIP_DECL_PRESOLFREE((*presolfree))	,
		SCIP_DECL_PRESOLINIT((*presolinit))	,
		SCIP_DECL_PRESOLEXIT((*presolexit))	,
		SCIP_DECL_PRESOLINITPRE((*presolinitpre))	,
		SCIP_DECL_PRESOLEXITPRE((*presolexitpre))	,
		SCIP_DECL_PRESOLEXEC((*presolexec))	,
		SCIP_PRESOLDATA *	presoldata
	)

creates a presolver and includes it in SCIP

Note

method has all presolver callbacks as arguments and is thus changed every time a new callback is added in future releases; consider using SCIPincludePresolBasic() and setter functions if you seek for a method which is less likely to change in future releases

creates a presolver and includes it in SCIP.

Note

method has all presolver callbacks as arguments and is thus changed every time a new callback is added in future releases; consider using SCIPincludePresolBasic() and setter functions if you seek for a method which is less likely to change in future releases

Parameters

scip	SCIP data structure
name	name of presolver
desc	description of presolver
priority	priority of the presolver (>= 0: before, < 0: after constraint handlers)
maxrounds	maximal number of presolving rounds the presolver participates in (-1: no limit)
timing	timing mask of the presolver
presoldata	presolver data

Definition at line 6846 of file scip.c.

References checkStage(), FALSE, Scip::mem, Scip::messagehdlr, NULL, SCIP_CALL, SCIP_INVALIDDATA, SCIP_OKAY, SCIPerrorMessage, SCIPfindPresol(), SCIPpresolCreate(), SCIPsetIncludePresol(), Scip::set, SCIP_Mem::setmem, and TRUE.

Referenced by SCIPincludeObjPresol().

SCIPincludePresolBasic()

SCIP_RETCODE SCIPincludePresolBasic	(	SCIP *	scip,
		SCIP_PRESOL **	presolptr,
		const char *	name,
		const char *	desc,
		int	priority,
		int	maxrounds,
		SCIP_PRESOLTIMING	timing,
		SCIP_DECL_PRESOLEXEC((*presolexec))	,
		SCIP_PRESOLDATA *	presoldata
	)

Creates a presolver and includes it in SCIP with its fundamental callback. All non-fundamental (or optional) callbacks as, e.g., init and exit callbacks, will be set to NULL. Optional callbacks can be set via specific setter functions. These are SCIPsetPresolCopy(), SCIPsetPresolFree(), SCIPsetPresolInit(), SCIPsetPresolExit(), SCIPsetPresolInitpre(), and SCIPsetPresolExitPre().

Note

if you want to set all callbacks with a single method call, consider using SCIPincludePresol() instead

creates a presolver and includes it in SCIP with its fundamental callback. All non-fundamental (or optional) callbacks as, e.g., init and exit callbacks, will be set to NULL. Optional callbacks can be set via specific setter functions. These are SCIPsetPresolCopy(), SCIPsetPresolFree(), SCIPsetPresolInit(), SCIPsetPresolExit(), SCIPsetPresolInitpre(), and SCIPsetPresolExitPre().

Note

if you want to set all callbacks with a single method call, consider using SCIPincludePresol() instead

Parameters

scip	SCIP data structure
presolptr	reference to presolver, or NULL
name	name of presolver
desc	description of presolver
priority	priority of the presolver (>= 0: before, < 0: after constraint handlers)
maxrounds	maximal number of presolving rounds the presolver participates in (-1: no limit)
timing	timing mask of the presolver
presoldata	presolver data

Definition at line 6889 of file scip.c.

References checkStage(), FALSE, Scip::mem, Scip::messagehdlr, NULL, SCIP_CALL, SCIP_INVALIDDATA, SCIP_OKAY, SCIPerrorMessage, SCIPfindPresol(), SCIPpresolCreate(), SCIPsetIncludePresol(), Scip::set, SCIP_Mem::setmem, and TRUE.

Referenced by SCIPincludePresolBoundshift(), SCIPincludePresolConvertinttobin(), SCIPincludePresolDomcol(), SCIPincludePresolDualagg(), SCIPincludePresolDualcomp(), SCIPincludePresolDualinfer(), SCIPincludePresolImplfree(), SCIPincludePresolImplics(), SCIPincludePresolInttobinary(), SCIPincludePresolQPKKTref(), SCIPincludePresolRedvub(), SCIPincludePresolStuffing(), SCIPincludePresolTrivial(), and SCIPincludePresolTworowbnd().

SCIPsetPresolCopy()

SCIP_RETCODE SCIPsetPresolCopy	(	SCIP *	scip,
		SCIP_PRESOL *	presol,
		SCIP_DECL_PRESOLCOPY((*presolcopy))
	)

sets copy method of presolver

Parameters

scip	SCIP data structure
presol	presolver

Definition at line 6924 of file scip.c.

References checkStage(), FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIPpresolSetCopy(), and TRUE.

Referenced by SCIPincludePresolBoundshift(), SCIPincludePresolConvertinttobin(), SCIPincludePresolDomcol(), SCIPincludePresolDualcomp(), SCIPincludePresolDualinfer(), SCIPincludePresolImplfree(), SCIPincludePresolImplics(), SCIPincludePresolInttobinary(), SCIPincludePresolQPKKTref(), SCIPincludePresolStuffing(), SCIPincludePresolTrivial(), and SCIPincludePresolTworowbnd().

SCIPsetPresolFree()

SCIP_RETCODE SCIPsetPresolFree	(	SCIP *	scip,
		SCIP_PRESOL *	presol,
		SCIP_DECL_PRESOLFREE((*presolfree))
	)

sets destructor method of presolver

Parameters

scip	SCIP data structure
presol	presolver

Definition at line 6940 of file scip.c.

References checkStage(), FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIPpresolSetFree(), and TRUE.

Referenced by SCIPincludePresolBoundshift(), SCIPincludePresolConvertinttobin(), SCIPincludePresolDomcol(), SCIPincludePresolDualcomp(), and SCIPincludePresolQPKKTref().

SCIPsetPresolInit()

SCIP_RETCODE SCIPsetPresolInit	(	SCIP *	scip,
		SCIP_PRESOL *	presol,
		SCIP_DECL_PRESOLINIT((*presolinit))
	)

sets initialization method of presolver

Parameters

scip	SCIP data structure
presol	presolver

Definition at line 6956 of file scip.c.

References checkStage(), FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIPpresolSetInit(), and TRUE.

SCIPsetPresolExit()

SCIP_RETCODE SCIPsetPresolExit	(	SCIP *	scip,
		SCIP_PRESOL *	presol,
		SCIP_DECL_PRESOLEXIT((*presolexit))
	)

sets deinitialization method of presolver

Parameters

scip	SCIP data structure
presol	presolver

Definition at line 6972 of file scip.c.

References checkStage(), FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIPpresolSetExit(), and TRUE.

SCIPsetPresolInitpre()

SCIP_RETCODE SCIPsetPresolInitpre	(	SCIP *	scip,
		SCIP_PRESOL *	presol,
		SCIP_DECL_PRESOLINITPRE((*presolinitpre))
	)

sets solving process initialization method of presolver

Parameters

scip	SCIP data structure
presol	presolver

Definition at line 6988 of file scip.c.

References checkStage(), FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIPpresolSetInitpre(), and TRUE.

SCIPsetPresolExitpre()

SCIP_RETCODE SCIPsetPresolExitpre	(	SCIP *	scip,
		SCIP_PRESOL *	presol,
		SCIP_DECL_PRESOLEXITPRE((*presolexitpre))
	)

sets solving process deinitialization method of presolver

Parameters

scip	SCIP data structure
presol	presolver

Definition at line 7004 of file scip.c.

References checkStage(), FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIPpresolSetExitpre(), and TRUE.

SCIPfindPresol()

SCIP_PRESOL* SCIPfindPresol	(	SCIP *	scip,
		const char *	name
	)

returns the presolver of the given name, or NULL if not existing

Parameters

scip	SCIP data structure
name	name of presolver

Definition at line 7020 of file scip.c.

References NULL, SCIPsetFindPresol(), and Scip::set.

Referenced by SCIPcopyConcurrentSolvingStats(), SCIPfindObjPresol(), SCIPincludePresol(), and SCIPincludePresolBasic().

SCIPgetPresols()

SCIP_PRESOL** SCIPgetPresols

(

SCIP *

scip

)

returns the array of currently available presolvers

Parameters

scip	SCIP data structure

Definition at line 7033 of file scip.c.

References NULL, SCIP_Set::presols, SCIPsetSortPresols(), and Scip::set.

Referenced by SCIP_DECL_DIALOGEXEC(), SCIPcopyConcurrentSolvingStats(), SCIPincludeDialogDefaultFix(), and SCIPincludeDialogDefaultSet().

SCIPgetNPresols()

int SCIPgetNPresols

(

SCIP *

scip

)

returns the number of currently available presolvers

Parameters

scip	SCIP data structure

Definition at line 7046 of file scip.c.

References SCIP_Set::npresols, NULL, and Scip::set.

Referenced by SCIP_DECL_DIALOGEXEC(), SCIPcopyConcurrentSolvingStats(), SCIPincludeDialogDefaultFix(), and SCIPincludeDialogDefaultSet().

SCIPsetPresolPriority()

SCIP_RETCODE SCIPsetPresolPriority	(	SCIP *	scip,
		SCIP_PRESOL *	presol,
		int	priority
	)

sets the priority of a presolver

Parameters

scip	SCIP data structure
presol	presolver
priority	new priority of the presolver

Definition at line 7057 of file scip.c.

References NULL, SCIP_OKAY, SCIPpresolSetPriority(), and Scip::set.

Referenced by SCIP_DECL_PARAMCHGD().