Scippy

SCIP

Solving Constraint Integer Programs

Macros | Functions
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"
#include "scip/pub_dive.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
 

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

#define HEUR_NAME   "actconsdiving"

Definition at line 29 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

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

Definition at line 30 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

#define HEUR_DISPCHAR   'a'

Definition at line 31 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

#define HEUR_PRIORITY   -1003700

Definition at line 32 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

#define HEUR_FREQ   -1

Definition at line 33 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

#define HEUR_FREQOFS   5

Definition at line 34 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

#define HEUR_MAXDEPTH   -1

Definition at line 35 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

#define HEUR_TIMING   SCIP_HEURTIMING_AFTERLPPLUNGE

Definition at line 36 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

#define HEUR_USESSUBSCIP   FALSE

does the heuristic use a secondary SCIP instance?

Definition at line 37 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

#define DIVESET_DIVETYPES   SCIP_DIVETYPE_INTEGRALITY

bit mask that represents all supported dive types

Definition at line 38 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

#define DEFAULT_MINRELDEPTH   0.0

minimal relative depth to start diving

Definition at line 44 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

#define DEFAULT_MAXRELDEPTH   1.0

maximal relative depth to start diving

Definition at line 45 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

#define DEFAULT_MAXLPITERQUOT   0.05

maximal fraction of diving LP iterations compared to node LP iterations

Definition at line 46 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

#define DEFAULT_MAXLPITEROFS   1000

additional number of allowed LP iterations

Definition at line 47 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

#define DEFAULT_MAXDIVEUBQUOT   0.8

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

Definition at line 48 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

#define DEFAULT_MAXDIVEAVGQUOT   0.0

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

Definition at line 51 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

#define DEFAULT_MAXDIVEUBQUOTNOSOL   1.0

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

Definition at line 54 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

#define DEFAULT_MAXDIVEAVGQUOTNOSOL   1.0

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

Definition at line 55 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

#define DEFAULT_BACKTRACK   TRUE

use one level of backtracking if infeasibility is encountered?

Definition at line 56 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

#define DEFAULT_LPRESOLVEDOMCHGQUOT   0.15

percentage of immediate domain changes during probing to trigger LP resolve

Definition at line 57 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

#define DEFAULT_LPSOLVEFREQ   0

LP solve frequency for diving heuristics

Definition at line 58 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

#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 59 of file heur_actconsdiving.c.

Referenced by SCIPincludeHeurActconsdiving().

Function Documentation

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 77 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().

static SCIP_DECL_HEURCOPY ( heurCopyActconsdiving  )
static

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

Definition at line 188 of file heur_actconsdiving.c.

Referenced by getNActiveConsScore().

static SCIP_DECL_HEURFREE ( heurFreeActconsdiving  )
static

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

Definition at line 202 of file heur_actconsdiving.c.

static SCIP_DECL_HEURINIT ( heurInitActconsdiving  )
static

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

Definition at line 223 of file heur_actconsdiving.c.

static SCIP_DECL_HEUREXIT ( heurExitActconsdiving  )
static

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

Definition at line 243 of file heur_actconsdiving.c.

static SCIP_DECL_HEUREXEC ( heurExecActconsdiving  )
static

execution method of primal heuristic

Definition at line 263 of file heur_actconsdiving.c.

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.

SCIP_RETCODE SCIPincludeHeurActconsdiving ( SCIP *  scip)

creates the actconsdiving heuristic and includes it in SCIP

Parameters
scipSCIP data structure

Definition at line 338 of file heur_actconsdiving.c.

References DEFAULT_BACKTRACK, DEFAULT_LPRESOLVEDOMCHGQUOT, DEFAULT_LPSOLVEFREQ, DEFAULT_MAXDIVEAVGQUOT, DEFAULT_MAXDIVEAVGQUOTNOSOL, DEFAULT_MAXDIVEUBQUOT, DEFAULT_MAXDIVEUBQUOTNOSOL, DEFAULT_MAXLPITEROFS, DEFAULT_MAXLPITERQUOT, DEFAULT_MAXRELDEPTH, DEFAULT_MINRELDEPTH, DEFAULT_ONLYLPBRANCHCANDS, 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, SCIPallocMemory, SCIPcreateDiveset(), SCIPincludeHeurBasic(), SCIPsetHeurCopy(), SCIPsetHeurExit(), SCIPsetHeurFree(), and SCIPsetHeurInit().

Referenced by SCIPincludeDefaultPlugins().