heur.h File Reference

Detailed Description

internal methods for primal heuristics

Author

Tobias Achterberg

Definition in file heur.h.

#include "scip/def.h"
#include "blockmemshell/memory.h"
#include "scip/type_retcode.h"
#include "scip/type_result.h"
#include "scip/type_set.h"
#include "scip/type_primal.h"
#include "scip/type_heur.h"
#include "scip/pub_heur.h"
#include "scip/stat.h"

Go to the source code of this file.

Functions
SCIP_RETCODE	SCIPdivesetCreate (SCIP_DIVESET **diveset, SCIP_HEUR *heur, const char *name, SCIP_SET *set, SCIP_MESSAGEHDLR *messagehdlr, BMS_BLKMEM *blkmem, SCIP_Real minreldepth, SCIP_Real maxreldepth, SCIP_Real maxlpiterquot, SCIP_Real maxdiveubquot, SCIP_Real maxdiveavgquot, SCIP_Real maxdiveubquotnosol, SCIP_Real maxdiveavgquotnosol, SCIP_Real lpresolvedomchgquot, int lpsolvefreq, int maxlpiterofs, SCIP_Bool backtrack, SCIP_Bool onlylpbranchcands, SCIP_DIVETYPE divetypemask, SCIP_DECL_DIVESETGETSCORE((*divesetgetscore)))
void	SCIPdivesetReset (SCIP_DIVESET *diveset)
void	SCIPdivesetUpdateStats (SCIP_DIVESET *diveset, SCIP_STAT *stat, int depth, int nprobingnodes, int nbacktracks, SCIP_Longint nsolsfound, SCIP_Longint nbestsolsfound, SCIP_Bool leavesol)
SCIP_RETCODE	SCIPdivesetGetScore (SCIP_DIVESET *diveset, SCIP_SET *set, SCIP_DIVETYPE divetype, SCIP_VAR *divecand, SCIP_Real divecandsol, SCIP_Real divecandfrac, SCIP_Real *candscore, SCIP_Bool *roundup)
void	SCIPdivesetUpdateLPStats (SCIP_DIVESET *diveset, SCIP_STAT *stat, SCIP_Longint niterstoadd)
SCIP_RETCODE	SCIPheurCopyInclude (SCIP_HEUR *heur, SCIP_SET *set)
SCIP_RETCODE	SCIPheurCreate (SCIP_HEUR **heur, SCIP_SET *set, SCIP_MESSAGEHDLR *messagehdlr, BMS_BLKMEM *blkmem, const char *name, const char *desc, char dispchar, int priority, int freq, int freqofs, int maxdepth, unsigned int timingmask, SCIP_Bool usessubscip, SCIP_DECL_HEURCOPY((*heurcopy)), SCIP_DECL_HEURFREE((*heurfree)), SCIP_DECL_HEURINIT((*heurinit)), SCIP_DECL_HEUREXIT((*heurexit)), SCIP_DECL_HEURINITSOL((*heurinitsol)), SCIP_DECL_HEUREXITSOL((*heurexitsol)), SCIP_DECL_HEUREXEC((*heurexec)), SCIP_HEURDATA *heurdata)
SCIP_RETCODE	SCIPheurFree (SCIP_HEUR **heur, SCIP_SET *set)
SCIP_RETCODE	SCIPheurInit (SCIP_HEUR *heur, SCIP_SET *set)
SCIP_RETCODE	SCIPheurExit (SCIP_HEUR *heur, SCIP_SET *set)
SCIP_RETCODE	SCIPheurInitsol (SCIP_HEUR *heur, SCIP_SET *set)
SCIP_RETCODE	SCIPheurExitsol (SCIP_HEUR *heur, SCIP_SET *set)
SCIP_Bool	SCIPheurShouldBeExecuted (SCIP_HEUR *heur, int depth, int lpstateforkdepth, SCIP_HEURTIMING heurtiming, SCIP_Bool *delayed)
SCIP_RETCODE	SCIPheurExec (SCIP_HEUR *heur, SCIP_SET *set, SCIP_PRIMAL *primal, int depth, int lpstateforkdepth, SCIP_HEURTIMING heurtiming, SCIP_Bool nodeinfeasible, int *ndelayedheurs, SCIP_RESULT *result)
void	SCIPheurSetPriority (SCIP_HEUR *heur, SCIP_SET *set, int priority)
void	SCIPheurSetCopy (SCIP_HEUR *heur, SCIP_DECL_HEURCOPY((*heurcopy)))
void	SCIPheurSetFree (SCIP_HEUR *heur, SCIP_DECL_HEURFREE((*heurfree)))
void	SCIPheurSetInit (SCIP_HEUR *heur, SCIP_DECL_HEURINIT((*heurinit)))
void	SCIPheurSetExit (SCIP_HEUR *heur, SCIP_DECL_HEUREXIT((*heurexit)))
void	SCIPheurSetInitsol (SCIP_HEUR *heur, SCIP_DECL_HEURINITSOL((*heurinitsol)))
void	SCIPheurSetExitsol (SCIP_HEUR *heur, SCIP_DECL_HEUREXITSOL((*heurexitsol)))
void	SCIPheurEnableOrDisableClocks (SCIP_HEUR *heur, SCIP_Bool enable)

Function Documentation

SCIP_RETCODE SCIPdivesetCreate	(	SCIP_DIVESET **	diveset,
		SCIP_HEUR *	heur,
		const char *	name,
		SCIP_SET *	set,
		SCIP_MESSAGEHDLR *	messagehdlr,
		BMS_BLKMEM *	blkmem,
		SCIP_Real	minreldepth,
		SCIP_Real	maxreldepth,
		SCIP_Real	maxlpiterquot,
		SCIP_Real	maxdiveubquot,
		SCIP_Real	maxdiveavgquot,
		SCIP_Real	maxdiveubquotnosol,
		SCIP_Real	maxdiveavgquotnosol,
		SCIP_Real	lpresolvedomchgquot,
		int	lpsolvefreq,
		int	maxlpiterofs,
		SCIP_Bool	backtrack,
		SCIP_Bool	onlylpbranchcands,
		SCIP_DIVETYPE	divetypemask,
		SCIP_DECL_DIVESETGETSCORE((*divesetgetscore))
	)

create a set of diving heuristic settings

Parameters

diveset	pointer to the freshly created diveset
heur	the heuristic to which this dive setting belongs
name	name for the diveset, or NULL if the name of the heuristic should be used
set	global SCIP settings
messagehdlr	message handler
blkmem	block memory for parameter settings
minreldepth	minimal relative depth to start diving
maxreldepth	maximal relative depth to start diving
maxlpiterquot	maximal fraction of diving LP iterations compared to node LP iterations
maxdiveubquot	maximal quotient (curlowerbound - lowerbound)/(cutoffbound - lowerbound) where diving is performed (0.0: no limit)
maxdiveavgquot	maximal quotient (curlowerbound - lowerbound)/(avglowerbound - lowerbound) where diving is performed (0.0: no limit)
maxdiveubquotnosol	maximal UBQUOT when no solution was found yet (0.0: no limit)
maxdiveavgquotnosol	maximal AVGQUOT when no solution was found yet (0.0: no limit)
lpresolvedomchgquot	percentage of immediate domain changes during probing to trigger LP resolve
lpsolvefreq	LP solve frequency for (0: only if enough domain reductions are found by propagation)
maxlpiterofs	additional number of allowed LP iterations
backtrack	use one level of backtracking if infeasibility is encountered?
onlylpbranchcands	should only LP branching candidates be considered instead of the slower but more general constraint handler diving variable selection?
divetypemask	bit mask that represents the supported dive types by this dive set

Definition at line 176 of file heur.c.

References BMSallocMemory, BMSduplicateMemoryArray, FALSE, heurAddDiveset(), NULL, paramname, SCIP_ALLOC, SCIP_CALL, SCIP_MAXSTRLEN, SCIP_OKAY, SCIP_REAL_MAX, SCIPdivesetReset(), SCIPheurGetName(), SCIPsetAddBoolParam(), SCIPsetAddIntParam(), SCIPsetAddRealParam(), SCIPsnprintf(), and TRUE.

Referenced by SCIPcreateDiveset().

void SCIPdivesetReset

(

SCIP_DIVESET *

diveset

)

resets diving settings counters

Parameters

diveset

diveset to be reset

Definition at line 85 of file heur.c.

References SCIP_Diveset::maxdepth, SCIP_Diveset::maxsoldepth, SCIP_Diveset::mindepth, SCIP_Diveset::minsoldepth, SCIP_Diveset::nbestsolsfound, SCIP_Diveset::ncalls, SCIP_Diveset::nlpiterations, SCIP_Diveset::nlps, SCIP_Diveset::nsolcalls, SCIP_Diveset::nsolsfound, NULL, SCIP_Diveset::totaldepth, SCIP_Diveset::totalnbacktracks, SCIP_Diveset::totalnnodes, and SCIP_Diveset::totalsoldepth.

Referenced by SCIPdivesetCreate(), and SCIPheurInit().

void SCIPdivesetUpdateStats	(	SCIP_DIVESET *	diveset,
		SCIP_STAT *	stat,
		int	depth,
		int	nprobingnodes,
		int	nbacktracks,
		SCIP_Longint	nsolsfound,
		SCIP_Longint	nbestsolsfound,
		SCIP_Bool	leavesol
	)

update diveset statistics and global diveset statistics

Parameters

diveset	diveset to be reset
stat	global SCIP statistics
depth	the depth reached this time
nprobingnodes	the number of probing nodes explored this time
nbacktracks	the number of backtracks during probing this time
nsolsfound	number of new solutions found this time
nbestsolsfound	number of new best solutions found this time
leavesol	has the diving heuristic reached a feasible leaf

Definition at line 108 of file heur.c.

References MAX, SCIP_Diveset::maxdepth, SCIP_Diveset::maxsoldepth, MIN, SCIP_Diveset::mindepth, SCIP_Diveset::minsoldepth, SCIP_Diveset::nbestsolsfound, SCIP_Diveset::ncalls, SCIP_Stat::ndivesetcalls, SCIP_Diveset::nsolcalls, SCIP_Diveset::nsolsfound, NULL, SCIP_Diveset::totaldepth, SCIP_Stat::totaldivesetdepth, SCIP_Diveset::totalnbacktracks, SCIP_Diveset::totalnnodes, and SCIP_Diveset::totalsoldepth.

Referenced by SCIPupdateDivesetStats().

SCIP_RETCODE SCIPdivesetGetScore	(	SCIP_DIVESET *	diveset,
		SCIP_SET *	set,
		SCIP_DIVETYPE	divetype,
		SCIP_VAR *	divecand,
		SCIP_Real	divecandsol,
		SCIP_Real	divecandfrac,
		SCIP_Real *	candscore,
		SCIP_Bool *	roundup
	)

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

Parameters

diveset	general diving settings
set	SCIP settings
divetype	the type of diving that should be applied
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 599 of file heur.c.

References SCIP_Diveset::divetypemask, NULL, SCIP_CALL, and SCIP_OKAY.

Referenced by SCIPgetDivesetScore().

void SCIPdivesetUpdateLPStats	(	SCIP_DIVESET *	diveset,
		SCIP_STAT *	stat,
		SCIP_Longint	niterstoadd
	)

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

Parameters

diveset	diving settings
stat	global SCIP statistics
niterstoadd	additional number of LP iterations to be added

Definition at line 573 of file heur.c.

References SCIP_Stat::ndivesetlpiterations, SCIP_Stat::ndivesetlps, SCIP_Diveset::nlpiterations, and SCIP_Diveset::nlps.

Referenced by SCIPupdateDivesetLPStats().

SCIP_RETCODE SCIPheurCopyInclude	(	SCIP_HEUR *	heur,
		SCIP_SET *	set
	)

copies the given primal heuristic to a new scip

Parameters

heur	primal heuristic
set	SCIP_SET of SCIP to copy to

Definition at line 624 of file heur.c.

References NULL, SCIP_CALL, SCIP_OKAY, SCIPdebugMessage, and SCIPheurGetName().

Referenced by SCIPsetCopyPlugins().

SCIP_RETCODE SCIPheurCreate	(	SCIP_HEUR **	heur,
		SCIP_SET *	set,
		SCIP_MESSAGEHDLR *	messagehdlr,
		BMS_BLKMEM *	blkmem,
		const char *	name,
		const char *	desc,
		char	dispchar,
		int	priority,
		int	freq,
		int	freqofs,
		int	maxdepth,
		unsigned int	timingmask,
		SCIP_Bool	usessubscip,
		SCIP_DECL_HEURCOPY((*heurcopy))	,
		SCIP_DECL_HEURFREE((*heurfree))	,
		SCIP_DECL_HEURINIT((*heurinit))	,
		SCIP_DECL_HEUREXIT((*heurexit))	,
		SCIP_DECL_HEURINITSOL((*heurinitsol))	,
		SCIP_DECL_HEUREXITSOL((*heurexitsol))	,
		SCIP_DECL_HEUREXEC((*heurexec))	,
		SCIP_HEURDATA *	heurdata
	)

creates a primal heuristic

Parameters

heur	pointer to primal heuristic data structure
set	global SCIP settings
messagehdlr	message handler
blkmem	block memory for parameter settings
name	name of primal heuristic
desc	description of primal heuristic
dispchar	display character of primal heuristic
priority	priority of the primal heuristic
freq	frequency for calling primal heuristic
freqofs	frequency offset for calling primal heuristic
maxdepth	maximal depth level to call heuristic at (-1: no limit)
timingmask	positions in the node solving loop where heuristic should be executed
usessubscip	does the heuristic use a secondary SCIP instance?
heurdata	primal heuristic data

Definition at line 643 of file heur.c.

References BMSallocMemory, BMSduplicateMemoryArray, FALSE, NULL, paramname, SCIP_ALLOC, SCIP_CALL, SCIP_CLOCKTYPE_DEFAULT, SCIP_MAXSTRLEN, SCIP_OKAY, SCIPclockCreate(), SCIPsetAddIntParam(), SCIPsnprintf(), and TRUE.

Referenced by SCIPincludeHeur(), and SCIPincludeHeurBasic().

SCIP_RETCODE SCIPheurFree	(	SCIP_HEUR **	heur,
		SCIP_SET *	set
	)

calls destructor and frees memory of primal heuristic

Parameters

heur	pointer to primal heuristic data structure
set	global SCIP settings

Definition at line 728 of file heur.c.

References BMSfreeMemory, BMSfreeMemoryArray, BMSfreeMemoryArrayNull, divesetFree(), NULL, SCIP_CALL, SCIP_OKAY, and SCIPclockFree().

SCIP_RETCODE SCIPheurInit	(	SCIP_HEUR *	heur,
		SCIP_SET *	set
	)

initializes primal heuristic

Parameters

heur	primal heuristic
set	global SCIP settings

Definition at line 762 of file heur.c.

References SCIP_Heur::delaypos, SCIP_Heur::divesets, SCIP_Heur::heurclock, SCIP_Heur::initialized, SCIP_Heur::name, SCIP_Heur::nbestsolsfound, SCIP_Heur::ncalls, SCIP_Heur::ndivesets, SCIP_Heur::nsolsfound, NULL, SCIP_CALL, SCIP_INVALIDCALL, SCIP_OKAY, SCIPclockReset(), SCIPclockStart(), SCIPclockStop(), SCIPdivesetReset(), SCIPerrorMessage, SCIP_Heur::setuptime, and TRUE.

Referenced by SCIPsetInitPlugins().

SCIP_RETCODE SCIPheurExit	(	SCIP_HEUR *	heur,
		SCIP_SET *	set
	)

calls exit method of primal heuristic

Parameters

heur	primal heuristic
set	global SCIP settings

Definition at line 812 of file heur.c.

References FALSE, SCIP_Heur::initialized, SCIP_Heur::name, NULL, SCIP_CALL, SCIP_INVALIDCALL, SCIP_OKAY, SCIPclockStart(), SCIPclockStop(), SCIPerrorMessage, and SCIP_Heur::setuptime.

Referenced by SCIPsetExitPlugins().

SCIP_RETCODE SCIPheurInitsol	(	SCIP_HEUR *	heur,
		SCIP_SET *	set
	)

informs primal heuristic that the branch and bound process is being started

Parameters

heur	primal heuristic
set	global SCIP settings

Definition at line 842 of file heur.c.

References SCIP_Heur::delaypos, FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIPclockStart(), SCIPclockStop(), and SCIP_Heur::setuptime.

Referenced by SCIPsetExitprePlugins().

SCIP_RETCODE SCIPheurExitsol	(	SCIP_HEUR *	heur,
		SCIP_SET *	set
	)

informs primal heuristic that the branch and bound process data is being freed

Parameters

heur	primal heuristic
set	global SCIP settings

Definition at line 872 of file heur.c.

References NULL, SCIP_CALL, SCIP_OKAY, SCIPclockStart(), SCIPclockStop(), and SCIP_Heur::setuptime.

Referenced by SCIPsetInitsolPlugins().

SCIP_Bool SCIPheurShouldBeExecuted	(	SCIP_HEUR *	heur,
		int	depth,
		int	lpstateforkdepth,
		SCIP_HEURTIMING	heurtiming,
		SCIP_Bool *	delayed
	)

should the heuristic be executed at the given depth, frequency, timing, ...

Parameters

heur	primal heuristic
depth	depth of current node
lpstateforkdepth	depth of the last node with solved LP
heurtiming	current point in the node solving process
delayed	pointer to store whether the heuristic should be delayed

Definition at line 896 of file heur.c.

References SCIP_Heur::delaypos, FALSE, SCIP_Heur::freq, SCIP_Heur::freqofs, SCIP_Heur::maxdepth, SCIP_Bool, SCIP_HEURTIMING_AFTERLPNODE, SCIP_HEURTIMING_AFTERLPPLUNGE, SCIP_HEURTIMING_AFTERPSEUDONODE, SCIP_HEURTIMING_AFTERPSEUDOPLUNGE, SCIP_HEURTIMING_BEFOREPRESOL, SCIP_HEURTIMING_DURINGPRESOLLOOP, SCIP_Heur::timingmask, and TRUE.

Referenced by SCIPheurExec(), and SCIPprimalHeuristics().

SCIP_RETCODE SCIPheurExec	(	SCIP_HEUR *	heur,
		SCIP_SET *	set,
		SCIP_PRIMAL *	primal,
		int	depth,
		int	lpstateforkdepth,
		SCIP_HEURTIMING	heurtiming,
		SCIP_Bool	nodeinfeasible,
		int *	ndelayedheurs,
		SCIP_RESULT *	result
	)

calls execution method of primal heuristic

Parameters

heur	primal heuristic
set	global SCIP settings
primal	primal data
depth	depth of current node
lpstateforkdepth	depth of the last node with solved LP
heurtiming	current point in the node solving process
nodeinfeasible	was the current node already detected to be infeasible?
ndelayedheurs	pointer to count the number of delayed heuristics
result	pointer to store the result of the callback method

Definition at line 958 of file heur.c.

References SCIP_Heur::delaypos, FALSE, SCIP_Heur::freq, SCIP_Heur::freqofs, SCIP_Heur::heurclock, SCIP_Heur::maxdepth, SCIP_Heur::name, SCIP_Primal::nbestsolsfound, SCIP_Heur::nbestsolsfound, SCIP_Heur::ncalls, SCIP_Primal::nsolsfound, SCIP_Heur::nsolsfound, NULL, SCIP_Bool, SCIP_CALL, SCIP_DELAYED, SCIP_DIDNOTFIND, SCIP_DIDNOTRUN, SCIP_FOUNDSOL, SCIP_HEURTIMING_BEFOREPRESOL, SCIP_HEURTIMING_DURINGPRESOLLOOP, SCIP_INVALIDRESULT, SCIP_Longint, SCIP_OKAY, SCIPclockStart(), SCIPclockStop(), SCIPdebugMessage, SCIPerrorMessage, and SCIPheurShouldBeExecuted().

Referenced by SCIPprimalHeuristics().

void SCIPheurSetPriority	(	SCIP_HEUR *	heur,
		SCIP_SET *	set,
		int	priority
	)

sets priority of primal heuristic

Parameters

heur	primal heuristic
set	global SCIP settings
priority	new priority of the primal heuristic

Definition at line 1218 of file heur.c.

References FALSE, NULL, and SCIP_Heur::priority.

Referenced by SCIPsetHeurPriority().

void SCIPheurSetCopy	(	SCIP_HEUR *	heur,
		SCIP_DECL_HEURCOPY((*heurcopy))
	)

sets copy callback of primal heuristic

Parameters

heur	primal heuristic

Definition at line 1081 of file heur.c.

References NULL.

Referenced by SCIPsetHeurCopy().

void SCIPheurSetFree	(	SCIP_HEUR *	heur,
		SCIP_DECL_HEURFREE((*heurfree))
	)

sets destructor callback of primal heuristic

Parameters

heur	primal heuristic

Definition at line 1092 of file heur.c.

References NULL.

Referenced by SCIPsetHeurFree().

void SCIPheurSetInit	(	SCIP_HEUR *	heur,
		SCIP_DECL_HEURINIT((*heurinit))
	)

sets initialization callback of primal heuristic

Parameters

heur	primal heuristic

Definition at line 1103 of file heur.c.

References NULL.

Referenced by SCIPsetHeurInit().

void SCIPheurSetExit	(	SCIP_HEUR *	heur,
		SCIP_DECL_HEUREXIT((*heurexit))
	)

sets deinitialization callback of primal heuristic

Parameters

heur	primal heuristic

Definition at line 1114 of file heur.c.

References NULL.

Referenced by SCIPsetHeurExit().

void SCIPheurSetInitsol	(	SCIP_HEUR *	heur,
		SCIP_DECL_HEURINITSOL((*heurinitsol))
	)

sets solving process initialization callback of primal heuristic

Parameters

heur	primal heuristic

Definition at line 1125 of file heur.c.

References NULL.

Referenced by SCIPsetHeurInitsol().

void SCIPheurSetExitsol	(	SCIP_HEUR *	heur,
		SCIP_DECL_HEUREXITSOL((*heurexitsol))
	)

sets solving process deinitialization callback of primal heuristic

Parameters

heur	primal heuristic

Definition at line 1136 of file heur.c.

References NULL.

Referenced by SCIPsetHeurExitsol().

void SCIPheurEnableOrDisableClocks	(	SCIP_HEUR *	heur,
		SCIP_Bool	enable
	)

enables or disables all clocks of heur, depending on the value of the flag

Parameters

heur	the heuristic for which all clocks should be enabled or disabled
enable	should the clocks of the heuristic be enabled?

Definition at line 1313 of file heur.c.

References SCIP_Heur::heurclock, NULL, SCIPclockEnableOrDisable(), and SCIP_Heur::setuptime.

Referenced by SCIPsetSetReoptimizationParams().