heur_pscostdiving.c File Reference

Detailed Description

LP diving heuristic that chooses fixings w.r.t. the pseudo cost values.

Author

Tobias Achterberg

Definition in file heur_pscostdiving.c.

#include <assert.h>
#include <string.h>
#include "scip/heur_pscostdiving.h"

Go to the source code of this file.

Macros
#define	HEUR_NAME   "pscostdiving"
#define	HEUR_DESC   "LP diving heuristic that chooses fixings w.r.t. the pseudo cost values"
#define	HEUR_DISPCHAR   'p'
#define	HEUR_PRIORITY   -1002000
#define	HEUR_FREQ   10
#define	HEUR_FREQOFS   2
#define	HEUR_MAXDEPTH   -1
#define	HEUR_TIMING   SCIP_HEURTIMING_AFTERLPPLUNGE
#define	HEUR_USESSUBSCIP   FALSE
#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	MINLPITER   10000

Functions
static void	calcPscostQuot (SCIP *scip, SCIP_VAR *var, SCIP_Real primsol, SCIP_Real frac, int rounddir, SCIP_Real *pscostquot, SCIP_Bool *roundup)
static	SCIP_DECL_HEURCOPY (heurCopyPscostdiving)
static	SCIP_DECL_HEURFREE (heurFreePscostdiving)
static	SCIP_DECL_HEURINIT (heurInitPscostdiving)
static	SCIP_DECL_HEUREXIT (heurExitPscostdiving)
static	SCIP_DECL_HEUREXEC (heurExecPscostdiving)
SCIP_RETCODE	SCIPincludeHeurPscostdiving (SCIP *scip)

Macro Definition Documentation

#define HEUR_NAME   "pscostdiving"

Definition at line 29 of file heur_pscostdiving.c.

Referenced by SCIP_DECL_HEURCOPY(), SCIP_DECL_HEUREXEC(), SCIP_DECL_HEUREXIT(), SCIP_DECL_HEURFREE(), SCIP_DECL_HEURINIT(), and SCIPincludeHeurPscostdiving().

#define HEUR_DESC   "LP diving heuristic that chooses fixings w.r.t. the pseudo cost values"

Definition at line 30 of file heur_pscostdiving.c.

Referenced by SCIPincludeHeurPscostdiving().

#define HEUR_DISPCHAR   'p'

Definition at line 31 of file heur_pscostdiving.c.

Referenced by SCIPincludeHeurPscostdiving().

#define HEUR_PRIORITY   -1002000

Definition at line 32 of file heur_pscostdiving.c.

Referenced by SCIPincludeHeurPscostdiving().

#define HEUR_FREQ   10

Definition at line 33 of file heur_pscostdiving.c.

Referenced by SCIPincludeHeurPscostdiving().

#define HEUR_FREQOFS   2

Definition at line 34 of file heur_pscostdiving.c.

Referenced by SCIPincludeHeurPscostdiving().

#define HEUR_MAXDEPTH   -1

Definition at line 35 of file heur_pscostdiving.c.

Referenced by SCIPincludeHeurPscostdiving().

#define HEUR_TIMING   SCIP_HEURTIMING_AFTERLPPLUNGE

Definition at line 36 of file heur_pscostdiving.c.

Referenced by SCIPincludeHeurPscostdiving().

#define HEUR_USESSUBSCIP   FALSE

does the heuristic use a secondary SCIP instance?

Definition at line 37 of file heur_pscostdiving.c.

Referenced by SCIPincludeHeurPscostdiving().

#define DEFAULT_MINRELDEPTH   0.0

minimal relative depth to start diving

Definition at line 44 of file heur_pscostdiving.c.

Referenced by SCIPincludeHeurPscostdiving().

#define DEFAULT_MAXRELDEPTH   1.0

maximal relative depth to start diving

Definition at line 45 of file heur_pscostdiving.c.

Referenced by SCIPincludeHeurPscostdiving().

#define DEFAULT_MAXLPITERQUOT   0.05

maximal fraction of diving LP iterations compared to node LP iterations

Definition at line 46 of file heur_pscostdiving.c.

Referenced by SCIPincludeHeurPscostdiving().

#define DEFAULT_MAXLPITEROFS   1000

additional number of allowed LP iterations

Definition at line 47 of file heur_pscostdiving.c.

Referenced by SCIPincludeHeurPscostdiving().

#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_pscostdiving.c.

Referenced by SCIPincludeHeurPscostdiving().

#define DEFAULT_MAXDIVEAVGQUOT   0.0

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

Definition at line 50 of file heur_pscostdiving.c.

Referenced by SCIPincludeHeurPscostdiving().

#define DEFAULT_MAXDIVEUBQUOTNOSOL   0.1

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

Definition at line 52 of file heur_pscostdiving.c.

Referenced by SCIPincludeHeurPscostdiving().

#define DEFAULT_MAXDIVEAVGQUOTNOSOL   0.0

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

Definition at line 53 of file heur_pscostdiving.c.

Referenced by SCIPincludeHeurPscostdiving().

#define DEFAULT_BACKTRACK   TRUE

use one level of backtracking if infeasibility is encountered?

Definition at line 54 of file heur_pscostdiving.c.

Referenced by SCIPincludeHeurPscostdiving().

#define MINLPITER   10000

minimal number of LP iterations allowed in each LP solving call

Definition at line 56 of file heur_pscostdiving.c.

Referenced by SCIP_DECL_HEUREXEC().

Function Documentation

static void calcPscostQuot ( SCIP *  scip, SCIP_VAR *  var, SCIP_Real  primsol, SCIP_Real  frac, int  rounddir, SCIP_Real *  pscostquot, SCIP_Bool *  roundup  )

static

calculates the pseudocost score for a given variable w.r.t. a given solution value and a given rounding direction

Parameters

scip	SCIP data structure
var	problem variable
primsol	primal solution of variable
frac	fractionality of variable
rounddir	-1: round down, +1: round up, 0: select due to pseudo cost values
pscostquot	pointer to store pseudo cost quotient
roundup	pointer to store whether the variable should be rounded up

Definition at line 85 of file heur_pscostdiving.c.

References FALSE, MAX, MIN, NULL, SCIP_Real, SCIPfeasFloor(), SCIPgetVarPseudocostVal(), SCIPisEQ(), SCIPvarGetRootSol(), SCIPvarIsBinary(), sqrt(), and TRUE.

Referenced by SCIP_DECL_HEUREXEC().

static SCIP_DECL_HEURCOPY ( heurCopyPscostdiving  )

static

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

Definition at line 147 of file heur_pscostdiving.c.

References HEUR_NAME, NULL, SCIP_CALL, SCIP_OKAY, SCIPheurGetName(), and SCIPincludeHeurPscostdiving().

static SCIP_DECL_HEURFREE ( heurFreePscostdiving  )

static

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

Definition at line 161 of file heur_pscostdiving.c.

References HEUR_NAME, NULL, SCIP_OKAY, SCIPfreeMemory, SCIPheurGetData(), SCIPheurGetName(), and SCIPheurSetData().

static SCIP_DECL_HEURINIT ( heurInitPscostdiving  )

static

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

Definition at line 181 of file heur_pscostdiving.c.

References HEUR_NAME, NULL, SCIP_CALL, SCIP_OKAY, SCIPcreateSol(), SCIPheurGetData(), and SCIPheurGetName().

static SCIP_DECL_HEUREXIT ( heurExitPscostdiving  )

static

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

Definition at line 205 of file heur_pscostdiving.c.

References HEUR_NAME, NULL, SCIP_CALL, SCIP_OKAY, SCIPfreeSol(), SCIPheurGetData(), and SCIPheurGetName().

static SCIP_DECL_HEUREXEC ( heurExecPscostdiving  )

static

execution method of primal heuristic

Definition at line 225 of file heur_pscostdiving.c.

References calcPscostQuot(), FALSE, HEUR_NAME, MAX, MIN, MINLPITER, NULL, SCIP_Bool, SCIP_CALL, SCIP_DELAYED, SCIP_DIDNOTFIND, SCIP_DIDNOTRUN, SCIP_FOUNDSOL, SCIP_Longint, SCIP_LPSOLSTAT_INFEASIBLE, SCIP_LPSOLSTAT_OBJLIMIT, SCIP_LPSOLSTAT_OPTIMAL, SCIP_OKAY, SCIP_Real, SCIPbacktrackProbing(), SCIPceil(), SCIPchgVarLbProbing(), SCIPchgVarUbProbing(), SCIPdebugMessage, SCIPenableVarHistory(), SCIPendProbing(), SCIPfeasCeil(), SCIPfeasFloor(), SCIPgetAvgLowerbound(), SCIPgetCutoffbound(), SCIPgetDepth(), SCIPgetDualbound(), SCIPgetLastDivenode(), SCIPgetLowerbound(), SCIPgetLPBranchCands(), SCIPgetLPObjval(), SCIPgetLPSolstat(), SCIPgetMaxDepth(), SCIPgetNBinVars(), SCIPgetNIntVars(), SCIPgetNLPIterations(), SCIPgetNNodeLPIterations(), SCIPgetNNodes(), SCIPgetNSolsFound(), SCIPgetProbingDepth(), SCIPgetSolOrigObj(), SCIPhasCurrentNodeLP(), SCIPheurGetData(), SCIPheurGetName(), SCIPheurGetNBestSolsFound(), SCIPheurGetNCalls(), SCIPinfinity(), SCIPisFeasGT(), SCIPisFeasLT(), SCIPisGE(), SCIPisGT(), SCIPisLPSolBasic(), SCIPisLT(), SCIPisObjIntegral(), SCIPisStopped(), SCIPlinkLPSol(), SCIPnewProbingNode(), SCIPpropagateProbing(), SCIPretransformObj(), SCIProundSol(), SCIPsolveProbingLP(), SCIPstartProbing(), SCIPtrySol(), SCIPupdateVarPseudocost(), SCIPvarGetLbLocal(), SCIPvarGetName(), SCIPvarGetUbLocal(), SCIPvarMayRoundDown(), SCIPvarMayRoundUp(), SCIPwarningMessage(), and TRUE.

SCIP_RETCODE SCIPincludeHeurPscostdiving

(

SCIP *

scip

)

creates the pscostdiving heuristic and includes it in SCIP

Parameters

scip	SCIP data structure

Definition at line 644 of file heur_pscostdiving.c.

References DEFAULT_BACKTRACK, DEFAULT_MAXDIVEAVGQUOT, DEFAULT_MAXDIVEAVGQUOTNOSOL, DEFAULT_MAXDIVEUBQUOT, DEFAULT_MAXDIVEUBQUOTNOSOL, DEFAULT_MAXLPITEROFS, DEFAULT_MAXLPITERQUOT, DEFAULT_MAXRELDEPTH, DEFAULT_MINRELDEPTH, FALSE, HEUR_DESC, HEUR_DISPCHAR, HEUR_FREQ, HEUR_FREQOFS, HEUR_MAXDEPTH, HEUR_NAME, HEUR_PRIORITY, HEUR_TIMING, HEUR_USESSUBSCIP, NULL, SCIP_CALL, SCIP_OKAY, SCIP_REAL_MAX, SCIPaddBoolParam(), SCIPaddIntParam(), SCIPaddRealParam(), SCIPallocMemory, SCIPincludeHeurBasic(), SCIPsetHeurCopy(), SCIPsetHeurExit(), SCIPsetHeurFree(), SCIPsetHeurInit(), and TRUE.

Referenced by SCIP_DECL_HEURCOPY(), and SCIPincludeDefaultPlugins().