heur_actconsdiving.c File Reference

Detailed Description

LP diving heuristic that chooses fixings w.r.t. the active constraints the variable appear in.

Author

Tobias Achterberg

Definition in file heur_actconsdiving.c.

#include <assert.h>
#include <string.h>
#include "scip/heur_actconsdiving.h"

Go to the source code of this file.

Macros
#define	HEUR_NAME   "actconsdiving"
#define	HEUR_DESC   "LP diving heuristic that chooses fixings w.r.t. the active constraints"
#define	HEUR_DISPCHAR   'a'
#define	HEUR_PRIORITY   -1003700
#define	HEUR_FREQ   -1
#define	HEUR_FREQOFS   5
#define	HEUR_MAXDEPTH   -1
#define	HEUR_TIMING   SCIP_HEURTIMING_AFTERLPPLUNGE
#define	HEUR_USESSUBSCIP   FALSE
#define	DIVESET_DIVETYPES   SCIP_DIVETYPE_INTEGRALITY
#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_MAXDIVEUBQUOTNOSOL   1.0
#define	DEFAULT_MAXDIVEAVGQUOTNOSOL   1.0
#define	DEFAULT_BACKTRACK   TRUE
#define	DEFAULT_LPRESOLVEDOMCHGQUOT   0.15
#define	DEFAULT_LPSOLVEFREQ   0
#define	DEFAULT_ONLYLPBRANCHCANDS   TRUE
#define	DEFAULT_RANDSEED   149

Functions
static SCIP_Real	getNActiveConsScore (SCIP *scip, SCIP_SOL *sol, SCIP_VAR *var, SCIP_Real *downscore, SCIP_Real *upscore)
static	SCIP_DECL_HEURCOPY (heurCopyActconsdiving)
static	SCIP_DECL_HEURFREE (heurFreeActconsdiving)
static	SCIP_DECL_HEURINIT (heurInitActconsdiving)
static	SCIP_DECL_HEUREXIT (heurExitActconsdiving)
static	SCIP_DECL_HEUREXEC (heurExecActconsdiving)
static	SCIP_DECL_DIVESETGETSCORE (divesetGetScoreActconsdiving)
SCIP_RETCODE	SCIPincludeHeurActconsdiving (SCIP *scip)

Macro Definition Documentation

HEUR_NAME

#define HEUR_NAME   "actconsdiving"

Definition at line 28 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

HEUR_DESC

#define HEUR_DESC   "LP diving heuristic that chooses fixings w.r.t. the active constraints"

Definition at line 29 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

HEUR_DISPCHAR

#define HEUR_DISPCHAR   'a'

Definition at line 30 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

HEUR_PRIORITY

#define HEUR_PRIORITY   -1003700

Definition at line 31 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

HEUR_FREQ

#define HEUR_FREQ   -1

Definition at line 32 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

HEUR_FREQOFS

#define HEUR_FREQOFS   5

Definition at line 33 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

HEUR_MAXDEPTH

#define HEUR_MAXDEPTH   -1

Definition at line 34 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

HEUR_TIMING

#define HEUR_TIMING   SCIP_HEURTIMING_AFTERLPPLUNGE

Definition at line 35 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

HEUR_USESSUBSCIP

#define HEUR_USESSUBSCIP   FALSE

does the heuristic use a secondary SCIP instance?

Definition at line 36 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

DIVESET_DIVETYPES

#define DIVESET_DIVETYPES   SCIP_DIVETYPE_INTEGRALITY

bit mask that represents all supported dive types

Definition at line 37 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

DEFAULT_MINRELDEPTH

#define DEFAULT_MINRELDEPTH   0.0

minimal relative depth to start diving

Definition at line 43 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

DEFAULT_MAXRELDEPTH

#define DEFAULT_MAXRELDEPTH   1.0

maximal relative depth to start diving

Definition at line 44 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

DEFAULT_MAXLPITERQUOT

#define DEFAULT_MAXLPITERQUOT   0.05

maximal fraction of diving LP iterations compared to node LP iterations

Definition at line 45 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

DEFAULT_MAXLPITEROFS

#define DEFAULT_MAXLPITEROFS   1000

additional number of allowed LP iterations

Definition at line 46 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

DEFAULT_MAXDIVEUBQUOT

#define DEFAULT_MAXDIVEUBQUOT   0.8

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

Definition at line 47 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

DEFAULT_MAXDIVEAVGQUOT

#define DEFAULT_MAXDIVEAVGQUOT   0.0

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

Definition at line 50 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

DEFAULT_MAXDIVEUBQUOTNOSOL

#define DEFAULT_MAXDIVEUBQUOTNOSOL   1.0

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

Definition at line 53 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

DEFAULT_MAXDIVEAVGQUOTNOSOL

#define DEFAULT_MAXDIVEAVGQUOTNOSOL   1.0

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

Definition at line 54 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

DEFAULT_BACKTRACK

#define DEFAULT_BACKTRACK   TRUE

use one level of backtracking if infeasibility is encountered?

Definition at line 55 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

DEFAULT_LPRESOLVEDOMCHGQUOT

#define DEFAULT_LPRESOLVEDOMCHGQUOT   0.15

percentage of immediate domain changes during probing to trigger LP resolve

Definition at line 56 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

DEFAULT_LPSOLVEFREQ

#define DEFAULT_LPSOLVEFREQ   0

LP solve frequency for diving heuristics

Definition at line 57 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

DEFAULT_ONLYLPBRANCHCANDS

#define DEFAULT_ONLYLPBRANCHCANDS   TRUE

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

Definition at line 58 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

DEFAULT_RANDSEED

#define DEFAULT_RANDSEED   149

default random seed

Definition at line 61 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

Function Documentation

getNActiveConsScore()

static SCIP_Real getNActiveConsScore ( SCIP *  scip, SCIP_SOL *  sol, SCIP_VAR *  var, SCIP_Real *  downscore, SCIP_Real *  upscore  )

static

returns a score value for the given variable based on the active constraints that the variable appears in

Parameters

scip	SCIP data structure
sol	working solution
var	variable to get the score value for
downscore	pointer to store the score for branching downwards
upscore	pointer to store the score for branching upwards

Definition at line 76 of file heur_actconsdiving.c.

References NULL, SCIP_DECL_HEURCOPY(), SCIP_Real, SCIP_VARSTATUS_COLUMN, SCIPcolGetNLPNonz(), SCIPcolGetRows(), SCIPcolGetVals(), SCIPgetBranchScore(), SCIPgetNLPRows(), SCIPgetRowSolActivity(), SCIPisFeasEQ(), SCIPisFeasNegative(), SCIPisFeasPositive(), SCIProwGetDualsol(), SCIProwGetLhs(), SCIProwGetNorm(), SCIProwGetRhs(), SCIPvarGetCol(), and SCIPvarGetStatus().

SCIP_DECL_HEURCOPY()

static SCIP_DECL_HEURCOPY ( heurCopyActconsdiving  )

static

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

Definition at line 187 of file heur_actconsdiving.c.

Referenced by getNActiveConsScore().

SCIP_DECL_HEURFREE()

static SCIP_DECL_HEURFREE ( heurFreeActconsdiving  )

static

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

Definition at line 201 of file heur_actconsdiving.c.

SCIP_DECL_HEURINIT()

static SCIP_DECL_HEURINIT ( heurInitActconsdiving  )

static

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

Definition at line 222 of file heur_actconsdiving.c.

SCIP_DECL_HEUREXIT()

static SCIP_DECL_HEUREXIT ( heurExitActconsdiving  )

static

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

Definition at line 242 of file heur_actconsdiving.c.

SCIP_DECL_HEUREXEC()

static SCIP_DECL_HEUREXEC ( heurExecActconsdiving  )

static

execution method of primal heuristic

Definition at line 263 of file heur_actconsdiving.c.

SCIP_DECL_DIVESETGETSCORE()

static SCIP_DECL_DIVESETGETSCORE ( divesetGetScoreActconsdiving  )

static

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

Definition at line 290 of file heur_actconsdiving.c.