Detailed Description

LP diving heuristic that chooses fixings w.r.t. conflict locks.

Author: Jakob Witzig

Definition in file heur_conflictdiving.c.

#include "scip/heur_conflictdiving.h"
#include "scip/heuristics.h"
#include "scip/pub_heur.h"
#include "scip/pub_message.h"
#include "scip/pub_misc.h"
#include "scip/pub_var.h"
#include "scip/scip_heur.h"
#include "scip/scip_mem.h"
#include "scip/scip_numerics.h"
#include "scip/scip_param.h"
#include "scip/scip_sol.h"
#include "scip/scip_solvingstats.h"
#include <string.h>

Go to the source code of this file.

Macros
#define	HEUR_NAME "conflictdiving"

#define	HEUR_DESC "LP diving heuristic that chooses fixings w.r.t. conflict locks"

#define	HEUR_DISPCHAR '~'

#define	HEUR_PRIORITY -1000100

#define	HEUR_FREQ -1

#define	HEUR_FREQOFS 0

#define	HEUR_MAXDEPTH -1

#define	HEUR_TIMING SCIP_HEURTIMING_AFTERLPPLUNGE

#define	HEUR_USESSUBSCIP FALSE

#define	DIVESET_DIVETYPES SCIP_DIVETYPE_INTEGRALITY \| SCIP_DIVETYPE_SOS1VARIABLE

#define	DEFAULT_RANDSEED 151

#define	DEFAULT_MINRELDEPTH 0.0

#define	DEFAULT_MAXRELDEPTH 1.0

#define	DEFAULT_MAXLPITERQUOT 0.15

#define	DEFAULT_MAXLPITEROFS 1000

#define	DEFAULT_MAXDIVEUBQUOT 0.8

#define	DEFAULT_MAXDIVEAVGQUOT 0.0

#define	DEFAULT_MAXDIVEUBQUOTNOSOL 0.1

#define	DEFAULT_MAXDIVEAVGQUOTNOSOL 0.0

#define	DEFAULT_BACKTRACK TRUE

#define	DEFAULT_LPRESOLVEDOMCHGQUOT 0.15

#define	DEFAULT_LPSOLVEFREQ 0

#define	DEFAULT_ONLYLPBRANCHCANDS FALSE

#define	DEFAULT_LOCKWEIGHT 1.0

#define	DEFAULT_LIKECOEF FALSE

#define	DEFAULT_MAXVIOL TRUE

#define	DEFAULT_MINCONFLICTLOCKS 5

#define	MIN_RAND 1e-06

#define	MAX_RAND 1e-05

Functions
static	SCIP_DECL_HEURCOPY (heurCopyConflictdiving)

static	SCIP_DECL_HEURFREE (heurFreeConflictdiving)

static	SCIP_DECL_HEURINIT (heurInitConflictdiving)

static	SCIP_DECL_HEUREXIT (heurExitConflictdiving)

static	SCIP_DECL_HEUREXEC (heurExecConflictdiving)

static SCIP_RETCODE	getScoreLikeCoefdiving (SCIP scip, SCIP_HEUR heur, SCIP_HEURDATA heurdata, SCIP_RANDNUMGEN rng, SCIP_DIVESET diveset, SCIP_DIVETYPE divetype, SCIP_VAR cand, SCIP_Real candsol, SCIP_Real candsfrac, SCIP_Real score, SCIP_Bool roundup)

static SCIP_RETCODE	getScore (SCIP scip, SCIP_HEUR heur, SCIP_HEURDATA heurdata, SCIP_RANDNUMGEN rng, SCIP_DIVESET diveset, SCIP_DIVETYPE divetype, SCIP_VAR cand, SCIP_Real candsol, SCIP_Real candsfrac, SCIP_Real score, SCIP_Bool roundup)

static	SCIP_DECL_DIVESETGETSCORE (divesetGetScoreConflictdiving)

SCIP_RETCODE	SCIPincludeHeurConflictdiving (SCIP *scip)

Macro Definition Documentation

◆ HEUR_NAME

#define HEUR_NAME "conflictdiving"

Definition at line 37 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ HEUR_DESC

#define HEUR_DESC "LP diving heuristic that chooses fixings w.r.t. conflict locks"

Definition at line 38 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ HEUR_DISPCHAR

#define HEUR_DISPCHAR '~'

Definition at line 39 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ HEUR_PRIORITY

#define HEUR_PRIORITY -1000100

Definition at line 40 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ HEUR_FREQ

#define HEUR_FREQ -1

Definition at line 41 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ HEUR_FREQOFS

#define HEUR_FREQOFS 0

Definition at line 42 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ HEUR_MAXDEPTH

#define HEUR_MAXDEPTH -1

Definition at line 43 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ HEUR_TIMING

#define HEUR_TIMING SCIP_HEURTIMING_AFTERLPPLUNGE

Definition at line 44 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ HEUR_USESSUBSCIP

#define HEUR_USESSUBSCIP FALSE

does the heuristic use a secondary SCIP instance?

Definition at line 45 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ DIVESET_DIVETYPES

#define DIVESET_DIVETYPES SCIP_DIVETYPE_INTEGRALITY | SCIP_DIVETYPE_SOS1VARIABLE

bit mask that represents all supported dive types

Definition at line 46 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ DEFAULT_RANDSEED

#define DEFAULT_RANDSEED 151

default random seed

Definition at line 47 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ DEFAULT_MINRELDEPTH

#define DEFAULT_MINRELDEPTH 0.0

minimal relative depth to start diving

Definition at line 53 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ DEFAULT_MAXRELDEPTH

#define DEFAULT_MAXRELDEPTH 1.0

maximal relative depth to start diving

Definition at line 54 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ DEFAULT_MAXLPITERQUOT

#define DEFAULT_MAXLPITERQUOT 0.15

maximal fraction of diving LP iterations compared to node LP iterations

Definition at line 55 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ DEFAULT_MAXLPITEROFS

#define DEFAULT_MAXLPITEROFS 1000

additional number of allowed LP iterations

Definition at line 56 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ DEFAULT_MAXDIVEUBQUOT

#define DEFAULT_MAXDIVEUBQUOT 0.8

maximal quotient (curlowerbound - lowerbound)/(cutoffbound - lowerbound) where diving is performed (0.0: no limit)

Definition at line 57 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ DEFAULT_MAXDIVEAVGQUOT

#define DEFAULT_MAXDIVEAVGQUOT 0.0

maximal quotient (curlowerbound - lowerbound)/(avglowerbound - lowerbound) where diving is performed (0.0: no limit)

Definition at line 60 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ DEFAULT_MAXDIVEUBQUOTNOSOL

#define DEFAULT_MAXDIVEUBQUOTNOSOL 0.1

maximal UBQUOT when no solution was found yet (0.0: no limit)

Definition at line 63 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ DEFAULT_MAXDIVEAVGQUOTNOSOL

#define DEFAULT_MAXDIVEAVGQUOTNOSOL 0.0

maximal AVGQUOT when no solution was found yet (0.0: no limit)

Definition at line 64 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ DEFAULT_BACKTRACK

#define DEFAULT_BACKTRACK TRUE

use one level of backtracking if infeasibility is encountered?

Definition at line 65 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ DEFAULT_LPRESOLVEDOMCHGQUOT

#define DEFAULT_LPRESOLVEDOMCHGQUOT 0.15

percentage of immediate domain changes during probing to trigger LP resolve

Definition at line 66 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ DEFAULT_LPSOLVEFREQ

#define DEFAULT_LPSOLVEFREQ 0

LP solve frequency for diving heuristics

Definition at line 67 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ DEFAULT_ONLYLPBRANCHCANDS

#define DEFAULT_ONLYLPBRANCHCANDS FALSE

should only LP branching candidates be considered instead of the slower but more general constraint handler diving variable selection?

Definition at line 68 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ DEFAULT_LOCKWEIGHT

#define DEFAULT_LOCKWEIGHT 1.0

weight used in a convex combination of conflict and variable locks

Definition at line 71 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ DEFAULT_LIKECOEF

#define DEFAULT_LIKECOEF FALSE

perform rounding like coefficient diving

Definition at line 72 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ DEFAULT_MAXVIOL

#define DEFAULT_MAXVIOL TRUE

prefer rounding direction with most violation

Definition at line 73 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ DEFAULT_MINCONFLICTLOCKS

#define DEFAULT_MINCONFLICTLOCKS 5

threshold for penalizing the score

Definition at line 74 of file heur_conflictdiving.c.

Referenced by SCIPincludeHeurConflictdiving().

◆ MIN_RAND

#define MIN_RAND 1e-06

Definition at line 190 of file heur_conflictdiving.c.

Referenced by getScore(), and getScoreLikeCoefdiving().

◆ MAX_RAND

#define MAX_RAND 1e-05

Definition at line 191 of file heur_conflictdiving.c.

Referenced by getScore(), and getScoreLikeCoefdiving().

Function Documentation

◆ SCIP_DECL_HEURCOPY()

static SCIP_DECL_HEURCOPY ( heurCopyConflictdiving )

static

copy method for primal heuristic plugins (called when SCIP copies plugins)

Definition at line 92 of file heur_conflictdiving.c.

◆ SCIP_DECL_HEURFREE()

static SCIP_DECL_HEURFREE ( heurFreeConflictdiving )

static

destructor of primal heuristic to free user data (called when SCIP is exiting)

Definition at line 106 of file heur_conflictdiving.c.

◆ SCIP_DECL_HEURINIT()

static SCIP_DECL_HEURINIT ( heurInitConflictdiving )

static

initialization method of primal heuristic (called after problem was transformed)

Definition at line 127 of file heur_conflictdiving.c.

◆ SCIP_DECL_HEUREXIT()

static SCIP_DECL_HEUREXIT ( heurExitConflictdiving )

static

deinitialization method of primal heuristic (called before transformed problem is freed)

Definition at line 147 of file heur_conflictdiving.c.

◆ SCIP_DECL_HEUREXEC()

static SCIP_DECL_HEUREXEC ( heurExecConflictdiving )

static

execution method of primal heuristic

Definition at line 166 of file heur_conflictdiving.c.

◆ getScoreLikeCoefdiving()

static SCIP_RETCODE getScoreLikeCoefdiving	(	SCIP *	scip,
		SCIP_HEUR *	heur,
		SCIP_HEURDATA *	heurdata,
		SCIP_RANDNUMGEN *	rng,
		SCIP_DIVESET *	diveset,
		SCIP_DIVETYPE	divetype,
		SCIP_VAR *	cand,
		SCIP_Real	candsol,
		SCIP_Real	candsfrac,
		SCIP_Real *	score,
		SCIP_Bool *	roundup
	)

static

calculate score variant 1: use rounding strategy like coefficent diving

Parameters

scip	SCIP data structure
heur	heuristic data structure
heurdata	heuristic data
rng	random number generator of the diveset
diveset	diveset of the heuristic
divetype	divetype of the heuristic
cand	diving candidate
candsol	diving candidate solution
candsfrac	fractionality of the candidate solution
score	pointer to store the score
roundup	pointer to store whether the candidate should be rounded upwards

Definition at line 195 of file heur_conflictdiving.c.

References getScore(), MAX_RAND, MIN_RAND, SCIP_Bool, SCIP_DIVETYPE_INTEGRALITY, SCIP_DIVETYPE_SOS1VARIABLE, SCIP_INVALIDDATA, SCIP_LOCKTYPE_CONFLICT, SCIP_LOCKTYPE_MODEL, SCIP_OKAY, SCIP_PROBINGSCORE_PENALTYRATIO, SCIP_Real, SCIPABORT, SCIPerrorMessage, SCIPisEQ(), SCIPisFeasNegative(), SCIPisFeasPositive(), SCIPisGT(), SCIPisZero(), SCIPrandomGetInt(), SCIPrandomGetReal(), SCIPvarGetNLocksDownType(), SCIPvarGetNLocksUpType(), and SCIPvarIsBinary().

◆ getScore()

static SCIP_RETCODE getScore	(	SCIP *	scip,
		SCIP_HEUR *	heur,
		SCIP_HEURDATA *	heurdata,
		SCIP_RANDNUMGEN *	rng,
		SCIP_DIVESET *	diveset,
		SCIP_DIVETYPE	divetype,
		SCIP_VAR *	cand,
		SCIP_Real	candsol,
		SCIP_Real	candsfrac,
		SCIP_Real *	score,
		SCIP_Bool *	roundup
	)

static

calculate score variant 2: use a rounding strategy that tends towards infeasibility

Parameters

scip	SCIP data structure
heur	heuristic data structure
heurdata	heuristic data
rng	random number generator of the diveset
diveset	diveset of the heuristic
divetype	divetype of the heuristic
cand	diving candidate
candsol	diving candidate solution
candsfrac	fractionality of the candidate solution
score	pointer to store the score
roundup	pointer to store whether the candidate should be rounded upwards

Definition at line 308 of file heur_conflictdiving.c.

References MAX_RAND, MIN_RAND, NULL, SCIP_Bool, SCIP_DECL_DIVESETGETSCORE(), SCIP_DIVETYPE_INTEGRALITY, SCIP_DIVETYPE_SOS1VARIABLE, SCIP_INVALIDDATA, SCIP_LOCKTYPE_CONFLICT, SCIP_LOCKTYPE_MODEL, SCIP_OKAY, SCIP_PROBINGSCORE_PENALTYRATIO, SCIP_Real, SCIPABORT, SCIPerrorMessage, SCIPisEQ(), SCIPisFeasNegative(), SCIPisFeasPositive(), SCIPisGT(), SCIPisLT(), SCIPisZero(), SCIPrandomGetInt(), SCIPrandomGetReal(), SCIPvarGetNLocksDownType(), SCIPvarGetNLocksUpType(), and SCIPvarIsBinary().

Referenced by getScoreLikeCoefdiving().

◆ SCIP_DECL_DIVESETGETSCORE()

static SCIP_DECL_DIVESETGETSCORE ( divesetGetScoreConflictdiving )

static

returns a score for the given candidate – the best candidate maximizes the diving score

Definition at line 452 of file heur_conflictdiving.c.

Referenced by getScore().

◆ SCIPincludeHeurConflictdiving()

SCIP_RETCODE SCIPincludeHeurConflictdiving ( SCIP * scip )

creates the conflictdiving heuristic and includes it in SCIP

Parameters

scip	SCIP data structure

Definition at line 487 of file heur_conflictdiving.c.

References DEFAULT_BACKTRACK, DEFAULT_LIKECOEF, DEFAULT_LOCKWEIGHT, DEFAULT_LPRESOLVEDOMCHGQUOT, DEFAULT_LPSOLVEFREQ, DEFAULT_MAXDIVEAVGQUOT, DEFAULT_MAXDIVEAVGQUOTNOSOL, DEFAULT_MAXDIVEUBQUOT, DEFAULT_MAXDIVEUBQUOTNOSOL, DEFAULT_MAXLPITEROFS, DEFAULT_MAXLPITERQUOT, DEFAULT_MAXRELDEPTH, DEFAULT_MAXVIOL, DEFAULT_MINCONFLICTLOCKS, DEFAULT_MINRELDEPTH, DEFAULT_ONLYLPBRANCHCANDS, DEFAULT_RANDSEED, DIVESET_DIVETYPES, HEUR_DESC, HEUR_DISPCHAR, HEUR_FREQ, HEUR_FREQOFS, HEUR_MAXDEPTH, HEUR_NAME, HEUR_PRIORITY, HEUR_TIMING, HEUR_USESSUBSCIP, NULL, SCIP_CALL, SCIP_OKAY, SCIPaddBoolParam(), SCIPaddIntParam(), SCIPaddRealParam(), SCIPallocBlockMemory, SCIPcreateDiveset(), SCIPincludeHeurBasic(), SCIPsetHeurCopy(), SCIPsetHeurExit(), SCIPsetHeurFree(), SCIPsetHeurInit(), and TRUE.

Referenced by SCIPincludeDefaultPlugins().

SCIP

Detailed Description

Macros

Functions

Macro Definition Documentation

◆ HEUR_NAME

◆ HEUR_DESC

◆ HEUR_DISPCHAR

◆ HEUR_PRIORITY

◆ HEUR_FREQ

◆ HEUR_FREQOFS

◆ HEUR_MAXDEPTH

◆ HEUR_TIMING

◆ HEUR_USESSUBSCIP

◆ DIVESET_DIVETYPES

◆ DEFAULT_RANDSEED

◆ DEFAULT_MINRELDEPTH

◆ DEFAULT_MAXRELDEPTH

◆ DEFAULT_MAXLPITERQUOT

◆ DEFAULT_MAXLPITEROFS

◆ DEFAULT_MAXDIVEUBQUOT

◆ DEFAULT_MAXDIVEAVGQUOT

◆ DEFAULT_MAXDIVEUBQUOTNOSOL

◆ DEFAULT_MAXDIVEAVGQUOTNOSOL

◆ DEFAULT_BACKTRACK

◆ DEFAULT_LPRESOLVEDOMCHGQUOT

◆ DEFAULT_LPSOLVEFREQ

◆ DEFAULT_ONLYLPBRANCHCANDS

◆ DEFAULT_LOCKWEIGHT

◆ DEFAULT_LIKECOEF

◆ DEFAULT_MAXVIOL

◆ DEFAULT_MINCONFLICTLOCKS

◆ MIN_RAND

◆ MAX_RAND

Function Documentation

◆ SCIP_DECL_HEURCOPY()

◆ SCIP_DECL_HEURFREE()

◆ SCIP_DECL_HEURINIT()

◆ SCIP_DECL_HEUREXIT()

◆ SCIP_DECL_HEUREXEC()

◆ getScoreLikeCoefdiving()

◆ getScore()

◆ SCIP_DECL_DIVESETGETSCORE()

◆ SCIPincludeHeurConflictdiving()