Scippy

SCIP

Solving Constraint Integer Programs

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 "scip/heur_actconsdiving.h"
#include "scip/heuristics.h"
#include "scip/pub_heur.h"
#include "scip/pub_lp.h"
#include "scip/pub_message.h"
#include "scip/pub_misc.h"
#include "scip/pub_var.h"
#include "scip/scip_branch.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   "actconsdiving"
 
#define HEUR_DESC   "LP diving heuristic that chooses fixings w.r.t. the active constraints"
 
#define HEUR_DISPCHAR   SCIP_HEURDISPCHAR_DIVING
 
#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 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_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
 
#define divesetAvailableActconsdiving   NULL
 

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 40 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 41 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

◆ HEUR_DISPCHAR

#define HEUR_DISPCHAR   SCIP_HEURDISPCHAR_DIVING

Definition at line 42 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

◆ HEUR_PRIORITY

#define HEUR_PRIORITY   -1003700

Definition at line 43 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

◆ HEUR_FREQ

#define HEUR_FREQ   -1

Definition at line 44 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

◆ HEUR_FREQOFS

#define HEUR_FREQOFS   5

Definition at line 45 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

◆ HEUR_MAXDEPTH

#define HEUR_MAXDEPTH   -1

Definition at line 46 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

◆ HEUR_TIMING

#define HEUR_TIMING   SCIP_HEURTIMING_AFTERLPPLUNGE

Definition at line 47 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 48 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 49 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

◆ DIVESET_ISPUBLIC

#define DIVESET_ISPUBLIC   TRUE

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

Definition at line 50 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

◆ DEFAULT_MINRELDEPTH

#define DEFAULT_MINRELDEPTH   0.0

minimal relative depth to start diving

Definition at line 56 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

◆ DEFAULT_MAXRELDEPTH

#define DEFAULT_MAXRELDEPTH   1.0

maximal relative depth to start diving

Definition at line 57 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 58 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

◆ DEFAULT_MAXLPITEROFS

#define DEFAULT_MAXLPITEROFS   1000

additional number of allowed LP iterations

Definition at line 59 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 60 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 63 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 66 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 67 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 68 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 69 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

◆ DEFAULT_LPSOLVEFREQ

#define DEFAULT_LPSOLVEFREQ   0

LP solve frequency for diving heuristics

Definition at line 70 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 71 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

◆ DEFAULT_RANDSEED

#define DEFAULT_RANDSEED   149

default random seed

Definition at line 74 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

◆ divesetAvailableActconsdiving

#define divesetAvailableActconsdiving   NULL

Definition at line 358 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
scipSCIP data structure
solworking solution
varvariable to get the score value for
downscorepointer to store the score for branching downwards
upscorepointer to store the score for branching upwards

Definition at line 89 of file heur_actconsdiving.c.

References NULL, r, 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 200 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 214 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 235 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 255 of file heur_actconsdiving.c.

◆ SCIP_DECL_HEUREXEC()

static SCIP_DECL_HEUREXEC ( heurExecActconsdiving  )
static

execution method of primal heuristic

Definition at line 275 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 302 of file heur_actconsdiving.c.