Scippy

SCIP

Solving Constraint Integer Programs

Macros | Functions
heur_coefdiving.c File Reference

Detailed Description

LP diving heuristic that chooses fixings w.r.t. the matrix coefficients.

Author
Tobias Achterberg
Marc Pfetsch

Indicator constraints are taken into account if present.

Definition in file heur_coefdiving.c.

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

Go to the source code of this file.

Macros

#define HEUR_NAME   "coefdiving"
 
#define HEUR_DESC   "LP diving heuristic that chooses fixings w.r.t. the matrix coefficients"
 
#define HEUR_DISPCHAR   'c'
 
#define HEUR_PRIORITY   -1001000
 
#define HEUR_FREQ   10
 
#define HEUR_FREQOFS   1
 
#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 (heurCopyCoefdiving)
 
static SCIP_DECL_HEURFREE (heurFreeCoefdiving)
 
static SCIP_DECL_HEURINIT (heurInitCoefdiving)
 
static SCIP_DECL_HEUREXIT (heurExitCoefdiving)
 
static SCIP_DECL_HEUREXEC (heurExecCoefdiving)
 
static SCIP_DECL_DIVESETGETSCORE (divesetGetScoreCoefdiving)
 
SCIP_RETCODE SCIPincludeHeurCoefdiving (SCIP *scip)
 

Macro Definition Documentation

#define HEUR_NAME   "coefdiving"

Definition at line 32 of file heur_coefdiving.c.

Referenced by SCIPincludeHeurCoefdiving().

#define HEUR_DESC   "LP diving heuristic that chooses fixings w.r.t. the matrix coefficients"

Definition at line 33 of file heur_coefdiving.c.

Referenced by SCIPincludeHeurCoefdiving().

#define HEUR_DISPCHAR   'c'

Definition at line 34 of file heur_coefdiving.c.

Referenced by SCIPincludeHeurCoefdiving().

#define HEUR_PRIORITY   -1001000

Definition at line 35 of file heur_coefdiving.c.

Referenced by SCIPincludeHeurCoefdiving().

#define HEUR_FREQ   10

Definition at line 36 of file heur_coefdiving.c.

Referenced by SCIPincludeHeurCoefdiving().

#define HEUR_FREQOFS   1

Definition at line 37 of file heur_coefdiving.c.

Referenced by SCIPincludeHeurCoefdiving().

#define HEUR_MAXDEPTH   -1

Definition at line 38 of file heur_coefdiving.c.

Referenced by SCIPincludeHeurCoefdiving().

#define HEUR_TIMING   SCIP_HEURTIMING_AFTERLPPLUNGE

Definition at line 39 of file heur_coefdiving.c.

Referenced by SCIPincludeHeurCoefdiving().

#define HEUR_USESSUBSCIP   FALSE

does the heuristic use a secondary SCIP instance?

Definition at line 40 of file heur_coefdiving.c.

Referenced by SCIPincludeHeurCoefdiving().

#define DIVESET_DIVETYPES   SCIP_DIVETYPE_INTEGRALITY | SCIP_DIVETYPE_SOS1VARIABLE

bit mask that represents all supported dive types

Definition at line 41 of file heur_coefdiving.c.

Referenced by SCIPincludeHeurCoefdiving().

#define DEFAULT_MINRELDEPTH   0.0

minimal relative depth to start diving

Definition at line 48 of file heur_coefdiving.c.

Referenced by SCIPincludeHeurCoefdiving().

#define DEFAULT_MAXRELDEPTH   1.0

maximal relative depth to start diving

Definition at line 49 of file heur_coefdiving.c.

Referenced by SCIPincludeHeurCoefdiving().

#define DEFAULT_MAXLPITERQUOT   0.05

maximal fraction of diving LP iterations compared to node LP iterations

Definition at line 50 of file heur_coefdiving.c.

Referenced by SCIPincludeHeurCoefdiving().

#define DEFAULT_MAXLPITEROFS   1000

additional number of allowed LP iterations

Definition at line 51 of file heur_coefdiving.c.

Referenced by SCIPincludeHeurCoefdiving().

#define DEFAULT_MAXDIVEUBQUOT   0.8

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

Definition at line 52 of file heur_coefdiving.c.

Referenced by SCIPincludeHeurCoefdiving().

#define DEFAULT_MAXDIVEAVGQUOT   0.0

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

Definition at line 55 of file heur_coefdiving.c.

Referenced by SCIPincludeHeurCoefdiving().

#define DEFAULT_MAXDIVEUBQUOTNOSOL   0.1

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

Definition at line 58 of file heur_coefdiving.c.

Referenced by SCIPincludeHeurCoefdiving().

#define DEFAULT_MAXDIVEAVGQUOTNOSOL   0.0

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

Definition at line 59 of file heur_coefdiving.c.

Referenced by SCIPincludeHeurCoefdiving().

#define DEFAULT_BACKTRACK   TRUE

use one level of backtracking if infeasibility is encountered?

Definition at line 60 of file heur_coefdiving.c.

Referenced by SCIPincludeHeurCoefdiving().

#define DEFAULT_LPRESOLVEDOMCHGQUOT   0.15

percentage of immediate domain changes during probing to trigger LP resolve

Definition at line 61 of file heur_coefdiving.c.

Referenced by SCIPincludeHeurCoefdiving().

#define DEFAULT_LPSOLVEFREQ   0

LP solve frequency for diving heuristics

Definition at line 62 of file heur_coefdiving.c.

Referenced by SCIPincludeHeurCoefdiving().

#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 63 of file heur_coefdiving.c.

Referenced by SCIPincludeHeurCoefdiving().

Function Documentation

static SCIP_DECL_HEURCOPY ( heurCopyCoefdiving  )
static

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

Definition at line 83 of file heur_coefdiving.c.

static SCIP_DECL_HEURFREE ( heurFreeCoefdiving  )
static

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

Definition at line 97 of file heur_coefdiving.c.

static SCIP_DECL_HEURINIT ( heurInitCoefdiving  )
static

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

Definition at line 117 of file heur_coefdiving.c.

static SCIP_DECL_HEUREXIT ( heurExitCoefdiving  )
static

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

Definition at line 137 of file heur_coefdiving.c.

static SCIP_DECL_HEUREXEC ( heurExecCoefdiving  )
static

execution method of primal heuristic

Definition at line 157 of file heur_coefdiving.c.

static SCIP_DECL_DIVESETGETSCORE ( divesetGetScoreCoefdiving  )
static

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

Definition at line 177 of file heur_coefdiving.c.

SCIP_RETCODE SCIPincludeHeurCoefdiving ( SCIP *  scip)

creates the coefdiving heuristic and includes it in SCIP

Parameters
scipSCIP data structure

Definition at line 253 of file heur_coefdiving.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().