heur_guideddiving.c File Reference

Detailed Description

LP diving heuristic that chooses fixings in direction of incumbent solutions.

Author

Tobias Achterberg

Definition in file heur_guideddiving.c.

#include "scip/heur_guideddiving.h"
#include "scip/heuristics.h"
#include "scip/pub_heur.h"
#include "scip/pub_message.h"
#include "scip/pub_sol.h"
#include "scip/pub_var.h"
#include "scip/scip_heur.h"
#include "scip/scip_lp.h"
#include "scip/scip_mem.h"
#include "scip/scip_numerics.h"
#include "scip/scip_prob.h"
#include "scip/scip_sol.h"
#include <string.h>

Go to the source code of this file.

Macros
#define	HEUR_NAME   "guideddiving"
#define	HEUR_DESC   "LP diving heuristic that chooses fixings in direction of incumbent solutions"
#define	HEUR_DISPCHAR   SCIP_HEURDISPCHAR_DIVING
#define	HEUR_PRIORITY   -1007000
#define	HEUR_FREQ   10
#define	HEUR_FREQOFS   7
#define	HEUR_MAXDEPTH   -1
#define	HEUR_TIMING   SCIP_HEURTIMING_AFTERLPPLUNGE
#define	HEUR_USESSUBSCIP   FALSE
#define	DIVESET_DIVETYPES   SCIP_DIVETYPE_INTEGRALITY
#define	DIVESET_ISPUBLIC   TRUE
#define	DEFAULT_MINRELDEPTH   0.0
#define	DEFAULT_MAXRELDEPTH   1.0
#define	DEFAULT_MAXLPITERQUOT   0.05
#define	DEFAULT_MAXLPITEROFS   1000
#define	DEFAULT_MAXDIVEUBQUOT   0.8
#define	DEFAULT_MAXDIVEAVGQUOT   0.0
#define	DEFAULT_BACKTRACK   TRUE
#define	DEFAULT_LPRESOLVEDOMCHGQUOT   0.15
#define	DEFAULT_LPSOLVEFREQ   0
#define	DEFAULT_ONLYLPBRANCHCANDS   FALSE
#define	DEFAULT_RANDSEED   127

Functions
static	SCIP_DECL_HEURCOPY (heurCopyGuideddiving)
static	SCIP_DECL_HEURFREE (heurFreeGuideddiving)
static	SCIP_DECL_HEURINIT (heurInitGuideddiving)
static	SCIP_DECL_HEUREXIT (heurExitGuideddiving)
static	SCIP_DECL_HEUREXEC (heurExecGuideddiving)
static	SCIP_DECL_DIVESETGETSCORE (divesetGetScoreGuideddiving)
static	SCIP_DECL_DIVESETAVAILABLE (divesetAvailableGuideddiving)
SCIP_RETCODE	SCIPincludeHeurGuideddiving (SCIP *scip)

Macro Definition Documentation

HEUR_NAME

#define HEUR_NAME   "guideddiving"

Definition at line 47 of file heur_guideddiving.c.

HEUR_DESC

#define HEUR_DESC   "LP diving heuristic that chooses fixings in direction of incumbent solutions"

Definition at line 48 of file heur_guideddiving.c.

HEUR_DISPCHAR

#define HEUR_DISPCHAR   SCIP_HEURDISPCHAR_DIVING

Definition at line 49 of file heur_guideddiving.c.

HEUR_PRIORITY

#define HEUR_PRIORITY   -1007000

Definition at line 50 of file heur_guideddiving.c.

HEUR_FREQ

#define HEUR_FREQ   10

Definition at line 51 of file heur_guideddiving.c.

HEUR_FREQOFS

#define HEUR_FREQOFS   7

Definition at line 52 of file heur_guideddiving.c.

HEUR_MAXDEPTH

#define HEUR_MAXDEPTH   -1

Definition at line 53 of file heur_guideddiving.c.

HEUR_TIMING

#define HEUR_TIMING   SCIP_HEURTIMING_AFTERLPPLUNGE

Definition at line 54 of file heur_guideddiving.c.

HEUR_USESSUBSCIP

#define HEUR_USESSUBSCIP   FALSE

does the heuristic use a secondary SCIP instance?

Definition at line 55 of file heur_guideddiving.c.

DIVESET_DIVETYPES

#define DIVESET_DIVETYPES   SCIP_DIVETYPE_INTEGRALITY

bit mask that represents all supported dive types

Definition at line 56 of file heur_guideddiving.c.

DIVESET_ISPUBLIC

#define DIVESET_ISPUBLIC   TRUE

is this dive set publicly available (ie., can be used by other primal heuristics?)

Definition at line 57 of file heur_guideddiving.c.

DEFAULT_MINRELDEPTH

#define DEFAULT_MINRELDEPTH   0.0

minimal relative depth to start diving

Definition at line 64 of file heur_guideddiving.c.

DEFAULT_MAXRELDEPTH

#define DEFAULT_MAXRELDEPTH   1.0

maximal relative depth to start diving

Definition at line 65 of file heur_guideddiving.c.

DEFAULT_MAXLPITERQUOT

#define DEFAULT_MAXLPITERQUOT   0.05

maximal fraction of diving LP iterations compared to node LP iterations

Definition at line 66 of file heur_guideddiving.c.

DEFAULT_MAXLPITEROFS

#define DEFAULT_MAXLPITEROFS   1000

additional number of allowed LP iterations

Definition at line 67 of file heur_guideddiving.c.

DEFAULT_MAXDIVEUBQUOT

#define DEFAULT_MAXDIVEUBQUOT   0.8

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

Definition at line 69 of file heur_guideddiving.c.

DEFAULT_MAXDIVEAVGQUOT

#define DEFAULT_MAXDIVEAVGQUOT   0.0

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

Definition at line 71 of file heur_guideddiving.c.

DEFAULT_BACKTRACK

#define DEFAULT_BACKTRACK   TRUE

use one level of backtracking if infeasibility is encountered?

Definition at line 72 of file heur_guideddiving.c.

DEFAULT_LPRESOLVEDOMCHGQUOT

#define DEFAULT_LPRESOLVEDOMCHGQUOT   0.15

percentage of immediate domain changes during probing to trigger LP resolve

Definition at line 73 of file heur_guideddiving.c.

DEFAULT_LPSOLVEFREQ

#define DEFAULT_LPSOLVEFREQ   0

LP solve frequency for diving heuristics

Definition at line 74 of file heur_guideddiving.c.

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 76 of file heur_guideddiving.c.

DEFAULT_RANDSEED

#define DEFAULT_RANDSEED   127

initial seed for random number generation

Definition at line 77 of file heur_guideddiving.c.

Function Documentation

SCIP_DECL_HEURCOPY()

static SCIP_DECL_HEURCOPY ( heurCopyGuideddiving  )

static

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

Definition at line 95 of file heur_guideddiving.c.

References HEUR_NAME, NULL, SCIP_CALL, SCIP_OKAY, SCIPheurGetName(), and SCIPincludeHeurGuideddiving().

SCIP_DECL_HEURFREE()

static SCIP_DECL_HEURFREE ( heurFreeGuideddiving  )

static

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

Definition at line 109 of file heur_guideddiving.c.

References HEUR_NAME, NULL, SCIP_OKAY, SCIPfreeBlockMemory, SCIPheurGetData(), SCIPheurGetName(), and SCIPheurSetData().

SCIP_DECL_HEURINIT()

static SCIP_DECL_HEURINIT ( heurInitGuideddiving  )

static

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

Definition at line 130 of file heur_guideddiving.c.

References HEUR_NAME, NULL, SCIP_CALL, SCIP_OKAY, SCIPcreateSol(), SCIPheurGetData(), and SCIPheurGetName().

SCIP_DECL_HEUREXIT()

static SCIP_DECL_HEUREXIT ( heurExitGuideddiving  )

static

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

Definition at line 150 of file heur_guideddiving.c.

References HEUR_NAME, NULL, SCIP_CALL, SCIP_OKAY, SCIPfreeSol(), SCIPheurGetData(), and SCIPheurGetName().

SCIP_DECL_HEUREXEC()

static SCIP_DECL_HEUREXEC ( heurExecGuideddiving  )

static

execution method of primal heuristic

Definition at line 170 of file heur_guideddiving.c.

References HEUR_NAME, NULL, SCIP_CALL, SCIP_DIDNOTRUN, SCIP_DIVECONTEXT_SINGLE, SCIP_OKAY, SCIPgetBestSol(), SCIPgetNContImplVars(), SCIPgetNContVars(), SCIPgetNSols(), SCIPgetNVars(), SCIPhasCurrentNodeLP(), SCIPheurGetData(), SCIPheurGetDivesets(), SCIPheurGetName(), SCIPheurGetNDivesets(), SCIPperformGenericDivingAlgorithm(), SCIPsolIsOriginal(), and SCIP_Diveset::sol.

SCIP_DECL_DIVESETGETSCORE()

static SCIP_DECL_DIVESETGETSCORE ( divesetGetScoreGuideddiving  )

static

calculate score and preferred rounding direction for the candidate variable; the best candidate maximizes the score

Definition at line 218 of file heur_guideddiving.c.

References FALSE, NULL, SCIP_OKAY, SCIP_Real, SCIPgetBestSol(), SCIPgetObjNorm(), SCIPgetSolVal(), SCIPisPositive(), SCIPsolIsOriginal(), SCIPvarGetObj(), SCIPvarIsBinary(), SCIPvarMayRoundDown(), SCIPvarMayRoundUp(), and TRUE.

SCIP_DECL_DIVESETAVAILABLE()

static SCIP_DECL_DIVESETAVAILABLE ( divesetAvailableGuideddiving  )

static

callback to check preconditions for diving, e.g., if an incumbent solution is available

Definition at line 275 of file heur_guideddiving.c.

References FALSE, SCIP_OKAY, SCIPgetBestSol(), SCIPgetNSols(), SCIPsolIsOriginal(), and TRUE.