Scippy

SCIP

Solving Constraint Integer Programs

Macros | Functions
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 <assert.h>
#include <string.h>
#include "scip/heur_guideddiving.h"
#include "scip/pub_dive.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   'g'
 
#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 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
 

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)
 
SCIP_RETCODE SCIPincludeHeurGuideddiving (SCIP *scip)
 

Macro Definition Documentation

#define HEUR_NAME   "guideddiving"

Definition at line 29 of file heur_guideddiving.c.

Referenced by SCIPincludeHeurGuideddiving().

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

Definition at line 30 of file heur_guideddiving.c.

Referenced by SCIPincludeHeurGuideddiving().

#define HEUR_DISPCHAR   'g'

Definition at line 31 of file heur_guideddiving.c.

Referenced by SCIPincludeHeurGuideddiving().

#define HEUR_PRIORITY   -1007000

Definition at line 32 of file heur_guideddiving.c.

Referenced by SCIPincludeHeurGuideddiving().

#define HEUR_FREQ   10

Definition at line 33 of file heur_guideddiving.c.

Referenced by SCIPincludeHeurGuideddiving().

#define HEUR_FREQOFS   7

Definition at line 34 of file heur_guideddiving.c.

Referenced by SCIPincludeHeurGuideddiving().

#define HEUR_MAXDEPTH   -1

Definition at line 35 of file heur_guideddiving.c.

Referenced by SCIPincludeHeurGuideddiving().

#define HEUR_TIMING   SCIP_HEURTIMING_AFTERLPPLUNGE

Definition at line 36 of file heur_guideddiving.c.

Referenced by SCIPincludeHeurGuideddiving().

#define HEUR_USESSUBSCIP   FALSE

does the heuristic use a secondary SCIP instance?

Definition at line 37 of file heur_guideddiving.c.

Referenced by SCIPincludeHeurGuideddiving().

#define DIVESET_DIVETYPES   SCIP_DIVETYPE_INTEGRALITY

bit mask that represents all supported dive types

Definition at line 38 of file heur_guideddiving.c.

Referenced by SCIPincludeHeurGuideddiving().

#define DEFAULT_MINRELDEPTH   0.0

minimal relative depth to start diving

Definition at line 45 of file heur_guideddiving.c.

Referenced by SCIPincludeHeurGuideddiving().

#define DEFAULT_MAXRELDEPTH   1.0

maximal relative depth to start diving

Definition at line 46 of file heur_guideddiving.c.

Referenced by SCIPincludeHeurGuideddiving().

#define DEFAULT_MAXLPITERQUOT   0.05

maximal fraction of diving LP iterations compared to node LP iterations

Definition at line 47 of file heur_guideddiving.c.

Referenced by SCIPincludeHeurGuideddiving().

#define DEFAULT_MAXLPITEROFS   1000

additional number of allowed LP iterations

Definition at line 48 of file heur_guideddiving.c.

Referenced by SCIPincludeHeurGuideddiving().

#define DEFAULT_MAXDIVEUBQUOT   0.8

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

Definition at line 49 of file heur_guideddiving.c.

Referenced by SCIPincludeHeurGuideddiving().

#define DEFAULT_MAXDIVEAVGQUOT   0.0

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

Definition at line 52 of file heur_guideddiving.c.

Referenced by SCIPincludeHeurGuideddiving().

#define DEFAULT_BACKTRACK   TRUE

use one level of backtracking if infeasibility is encountered?

Definition at line 55 of file heur_guideddiving.c.

Referenced by SCIPincludeHeurGuideddiving().

#define DEFAULT_LPRESOLVEDOMCHGQUOT   0.15

percentage of immediate domain changes during probing to trigger LP resolve

Definition at line 56 of file heur_guideddiving.c.

Referenced by SCIPincludeHeurGuideddiving().

#define DEFAULT_LPSOLVEFREQ   0

LP solve frequency for diving heuristics

Definition at line 57 of file heur_guideddiving.c.

Referenced by SCIPincludeHeurGuideddiving().

#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 58 of file heur_guideddiving.c.

Referenced by SCIPincludeHeurGuideddiving().

Function Documentation

static SCIP_DECL_HEURCOPY ( heurCopyGuideddiving  )
static

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

Definition at line 78 of file heur_guideddiving.c.

static SCIP_DECL_HEURFREE ( heurFreeGuideddiving  )
static

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

Definition at line 92 of file heur_guideddiving.c.

static SCIP_DECL_HEURINIT ( heurInitGuideddiving  )
static

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

Definition at line 113 of file heur_guideddiving.c.

static SCIP_DECL_HEUREXIT ( heurExitGuideddiving  )
static

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

Definition at line 133 of file heur_guideddiving.c.

static SCIP_DECL_HEUREXEC ( heurExecGuideddiving  )
static

execution method of primal heuristic

Definition at line 153 of file heur_guideddiving.c.

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 202 of file heur_guideddiving.c.

SCIP_RETCODE SCIPincludeHeurGuideddiving ( SCIP *  scip)

creates the guideddiving heuristic and includes it in SCIP

Parameters
scipSCIP data structure

Definition at line 262 of file heur_guideddiving.c.

References DEFAULT_BACKTRACK, DEFAULT_LPRESOLVEDOMCHGQUOT, DEFAULT_LPSOLVEFREQ, DEFAULT_MAXDIVEAVGQUOT, DEFAULT_MAXDIVEUBQUOT, 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().