Scippy

SCIP

Solving Constraint Integer Programs

Macros | Functions
heur_linesearchdiving.c File Reference

Detailed Description

LP diving heuristic that fixes variables with a large difference to their root solution.

Author
Tobias Achterberg

Definition in file heur_linesearchdiving.c.

#include <assert.h>
#include <string.h>
#include "scip/heur_linesearchdiving.h"
#include "scip/pub_dive.h"

Go to the source code of this file.

Macros

#define HEUR_NAME   "linesearchdiving"
 
#define HEUR_DESC   "LP diving heuristic that chooses fixings following the line from root solution to current solution"
 
#define HEUR_DISPCHAR   'l'
 
#define HEUR_PRIORITY   -1006000
 
#define HEUR_FREQ   10
 
#define HEUR_FREQOFS   6
 
#define HEUR_MAXDEPTH   -1
 
#define HEUR_TIMING   SCIP_HEURTIMING_AFTERLPPLUNGE
 
#define HEUR_USESSUBSCIP   FALSE
 
#define DIVESET_DIVETYPES   SCIP_DIVETYPE_INTEGRALITY | SCIP_DIVETYPE_SOS1VARIABLE
 
#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   0.1
 
#define DEFAULT_MAXDIVEAVGQUOTNOSOL   0.0
 
#define DEFAULT_BACKTRACK   TRUE
 
#define DEFAULT_LPRESOLVEDOMCHGQUOT   0.15
 
#define DEFAULT_LPSOLVEFREQ   0
 
#define DEFAULT_ONLYLPBRANCHCANDS   FALSE
 

Functions

static SCIP_DECL_HEURCOPY (heurCopyLinesearchdiving)
 
static SCIP_DECL_HEURFREE (heurFreeLinesearchdiving)
 
static SCIP_DECL_HEURINIT (heurInitLinesearchdiving)
 
static SCIP_DECL_HEUREXIT (heurExitLinesearchdiving)
 
static SCIP_DECL_HEUREXEC (heurExecLinesearchdiving)
 
static SCIP_DECL_DIVESETGETSCORE (divesetGetScoreLinesearchdiving)
 
SCIP_RETCODE SCIPincludeHeurLinesearchdiving (SCIP *scip)
 

Macro Definition Documentation

#define HEUR_NAME   "linesearchdiving"

Definition at line 29 of file heur_linesearchdiving.c.

Referenced by SCIPincludeHeurLinesearchdiving().

#define HEUR_DESC   "LP diving heuristic that chooses fixings following the line from root solution to current solution"

Definition at line 30 of file heur_linesearchdiving.c.

Referenced by SCIPincludeHeurLinesearchdiving().

#define HEUR_DISPCHAR   'l'

Definition at line 31 of file heur_linesearchdiving.c.

Referenced by SCIPincludeHeurLinesearchdiving().

#define HEUR_PRIORITY   -1006000

Definition at line 32 of file heur_linesearchdiving.c.

Referenced by SCIPincludeHeurLinesearchdiving().

#define HEUR_FREQ   10

Definition at line 33 of file heur_linesearchdiving.c.

Referenced by SCIPincludeHeurLinesearchdiving().

#define HEUR_FREQOFS   6

Definition at line 34 of file heur_linesearchdiving.c.

Referenced by SCIPincludeHeurLinesearchdiving().

#define HEUR_MAXDEPTH   -1

Definition at line 35 of file heur_linesearchdiving.c.

Referenced by SCIPincludeHeurLinesearchdiving().

#define HEUR_TIMING   SCIP_HEURTIMING_AFTERLPPLUNGE

Definition at line 36 of file heur_linesearchdiving.c.

Referenced by SCIPincludeHeurLinesearchdiving().

#define HEUR_USESSUBSCIP   FALSE

does the heuristic use a secondary SCIP instance?

Definition at line 37 of file heur_linesearchdiving.c.

Referenced by SCIPincludeHeurLinesearchdiving().

#define DIVESET_DIVETYPES   SCIP_DIVETYPE_INTEGRALITY | SCIP_DIVETYPE_SOS1VARIABLE

bit mask that represents all supported dive types

Definition at line 38 of file heur_linesearchdiving.c.

Referenced by SCIPincludeHeurLinesearchdiving().

#define DEFAULT_MINRELDEPTH   0.0

minimal relative depth to start diving

Definition at line 45 of file heur_linesearchdiving.c.

Referenced by SCIPincludeHeurLinesearchdiving().

#define DEFAULT_MAXRELDEPTH   1.0

maximal relative depth to start diving

Definition at line 46 of file heur_linesearchdiving.c.

Referenced by SCIPincludeHeurLinesearchdiving().

#define DEFAULT_MAXLPITERQUOT   0.05

maximal fraction of diving LP iterations compared to node LP iterations

Definition at line 47 of file heur_linesearchdiving.c.

Referenced by SCIPincludeHeurLinesearchdiving().

#define DEFAULT_MAXLPITEROFS   1000

additional number of allowed LP iterations

Definition at line 48 of file heur_linesearchdiving.c.

Referenced by SCIPincludeHeurLinesearchdiving().

#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_linesearchdiving.c.

Referenced by SCIPincludeHeurLinesearchdiving().

#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_linesearchdiving.c.

Referenced by SCIPincludeHeurLinesearchdiving().

#define DEFAULT_MAXDIVEUBQUOTNOSOL   0.1

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

Definition at line 55 of file heur_linesearchdiving.c.

Referenced by SCIPincludeHeurLinesearchdiving().

#define DEFAULT_MAXDIVEAVGQUOTNOSOL   0.0

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

Definition at line 56 of file heur_linesearchdiving.c.

Referenced by SCIPincludeHeurLinesearchdiving().

#define DEFAULT_BACKTRACK   TRUE

use one level of backtracking if infeasibility is encountered?

Definition at line 57 of file heur_linesearchdiving.c.

Referenced by SCIPincludeHeurLinesearchdiving().

#define DEFAULT_LPRESOLVEDOMCHGQUOT   0.15

percentage of immediate domain changes during probing to trigger LP resolve

Definition at line 58 of file heur_linesearchdiving.c.

Referenced by SCIPincludeHeurLinesearchdiving().

#define DEFAULT_LPSOLVEFREQ   0

LP solve frequency for diving heuristics

Definition at line 59 of file heur_linesearchdiving.c.

Referenced by SCIPincludeHeurLinesearchdiving().

#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 60 of file heur_linesearchdiving.c.

Referenced by SCIPincludeHeurLinesearchdiving().

Function Documentation

static SCIP_DECL_HEURCOPY ( heurCopyLinesearchdiving  )
static

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

Definition at line 86 of file heur_linesearchdiving.c.

static SCIP_DECL_HEURFREE ( heurFreeLinesearchdiving  )
static

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

Definition at line 100 of file heur_linesearchdiving.c.

static SCIP_DECL_HEURINIT ( heurInitLinesearchdiving  )
static

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

Definition at line 119 of file heur_linesearchdiving.c.

static SCIP_DECL_HEUREXIT ( heurExitLinesearchdiving  )
static

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

Definition at line 138 of file heur_linesearchdiving.c.

static SCIP_DECL_HEUREXEC ( heurExecLinesearchdiving  )
static

execution method of primal heuristic

Definition at line 157 of file heur_linesearchdiving.c.

static SCIP_DECL_DIVESETGETSCORE ( divesetGetScoreLinesearchdiving  )
static

returns a score for the given candidate – the best candidate maximizes the diving score

Definition at line 179 of file heur_linesearchdiving.c.

SCIP_RETCODE SCIPincludeHeurLinesearchdiving ( SCIP *  scip)

creates the linesearchdiving primal heuristic and includes it in SCIP

Parameters
scipSCIP data structure

Definition at line 257 of file heur_linesearchdiving.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().