Scippy

    SCIP

    Solving Constraint Integer Programs

    Macros | Functions
    heur_coefdiving.c File Reference
    Implementation files (.c files) » SCIP Default Plugins » Default Primal Heuristics

    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 "scip/heur_coefdiving.h"
    #include "scip/heuristics.h"
    #include "scip/pub_heur.h"
    #include "scip/pub_message.h"
    #include "scip/pub_misc.h"
    #include "scip/pub_var.h"
    #include "scip/scip_heur.h"
    #include "scip/scip_lp.h"
    #include "scip/scip_mem.h"
    #include "scip/scip_numerics.h"
    #include "scip/scip_sol.h"
    #include <string.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   SCIP_HEURDISPCHAR_DIVING
     
    #define HEUR_PRIORITY   -1001000
     
    #define HEUR_FREQ   -1
     
    #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 DIVESET_ISPUBLIC   TRUE
     
    #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
     
    #define DEFAULT_RANDSEED   83
     
    #define divesetAvailableCoefdiving   NULL
     

    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

    ◆ HEUR_NAME

    #define HEUR_NAME   "coefdiving"

    Definition at line 49 of file heur_coefdiving.c.

    ◆ HEUR_DESC

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

    Definition at line 50 of file heur_coefdiving.c.

    ◆ HEUR_DISPCHAR

    #define HEUR_DISPCHAR   SCIP_HEURDISPCHAR_DIVING

    Definition at line 51 of file heur_coefdiving.c.

    ◆ HEUR_PRIORITY

    #define HEUR_PRIORITY   -1001000

    Definition at line 52 of file heur_coefdiving.c.

    ◆ HEUR_FREQ

    #define HEUR_FREQ   -1

    Definition at line 53 of file heur_coefdiving.c.

    ◆ HEUR_FREQOFS

    #define HEUR_FREQOFS   1

    Definition at line 54 of file heur_coefdiving.c.

    ◆ HEUR_MAXDEPTH

    #define HEUR_MAXDEPTH   -1

    Definition at line 55 of file heur_coefdiving.c.

    ◆ HEUR_TIMING

    #define HEUR_TIMING   SCIP_HEURTIMING_AFTERLPPLUNGE

    Definition at line 56 of file heur_coefdiving.c.

    ◆ HEUR_USESSUBSCIP

    #define HEUR_USESSUBSCIP   FALSE

    does the heuristic use a secondary SCIP instance?

    Definition at line 57 of file heur_coefdiving.c.

    ◆ DIVESET_DIVETYPES

    #define DIVESET_DIVETYPES   SCIP_DIVETYPE_INTEGRALITY | SCIP_DIVETYPE_SOS1VARIABLE

    bit mask that represents all supported dive types

    Definition at line 58 of file heur_coefdiving.c.

    ◆ DIVESET_ISPUBLIC

    #define DIVESET_ISPUBLIC   TRUE

    is this dive set publicly available (ie., can be used by other primal heuristics?)

    Definition at line 59 of file heur_coefdiving.c.

    ◆ DEFAULT_MINRELDEPTH

    #define DEFAULT_MINRELDEPTH   0.0

    minimal relative depth to start diving

    Definition at line 66 of file heur_coefdiving.c.

    ◆ DEFAULT_MAXRELDEPTH

    #define DEFAULT_MAXRELDEPTH   1.0

    maximal relative depth to start diving

    Definition at line 67 of file heur_coefdiving.c.

    ◆ DEFAULT_MAXLPITERQUOT

    #define DEFAULT_MAXLPITERQUOT   0.05

    maximal fraction of diving LP iterations compared to node LP iterations

    Definition at line 68 of file heur_coefdiving.c.

    ◆ DEFAULT_MAXLPITEROFS

    #define DEFAULT_MAXLPITEROFS   1000

    additional number of allowed LP iterations

    Definition at line 69 of file heur_coefdiving.c.

    ◆ DEFAULT_MAXDIVEUBQUOT

    #define DEFAULT_MAXDIVEUBQUOT   0.8

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

    Definition at line 71 of file heur_coefdiving.c.

    ◆ DEFAULT_MAXDIVEAVGQUOT

    #define DEFAULT_MAXDIVEAVGQUOT   0.0

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

    Definition at line 73 of file heur_coefdiving.c.

    ◆ DEFAULT_MAXDIVEUBQUOTNOSOL

    #define DEFAULT_MAXDIVEUBQUOTNOSOL   0.1

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

    Definition at line 74 of file heur_coefdiving.c.

    ◆ DEFAULT_MAXDIVEAVGQUOTNOSOL

    #define DEFAULT_MAXDIVEAVGQUOTNOSOL   0.0

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

    Definition at line 75 of file heur_coefdiving.c.

    ◆ DEFAULT_BACKTRACK

    #define DEFAULT_BACKTRACK   TRUE

    use one level of backtracking if infeasibility is encountered?

    Definition at line 76 of file heur_coefdiving.c.

    ◆ DEFAULT_LPRESOLVEDOMCHGQUOT

    #define DEFAULT_LPRESOLVEDOMCHGQUOT   0.15

    percentage of immediate domain changes during probing to trigger LP resolve

    Definition at line 77 of file heur_coefdiving.c.

    ◆ DEFAULT_LPSOLVEFREQ

    #define DEFAULT_LPSOLVEFREQ   0

    LP solve frequency for diving heuristics

    Definition at line 78 of file heur_coefdiving.c.

    ◆ DEFAULT_ONLYLPBRANCHCANDS

    #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 80 of file heur_coefdiving.c.

    ◆ DEFAULT_RANDSEED

    #define DEFAULT_RANDSEED   83

    default random seed

    Definition at line 81 of file heur_coefdiving.c.

    ◆ divesetAvailableCoefdiving

    #define divesetAvailableCoefdiving   NULL

    Definition at line 280 of file heur_coefdiving.c.

    Function Documentation

    ◆ SCIP_DECL_HEURCOPY()

    static SCIP_DECL_HEURCOPY ( heurCopyCoefdiving  )
    		static

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

    Definition at line 99 of file heur_coefdiving.c.

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

    ◆ SCIP_DECL_HEURFREE()

    static SCIP_DECL_HEURFREE ( heurFreeCoefdiving  )
    		static

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

    Definition at line 113 of file heur_coefdiving.c.

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

    ◆ SCIP_DECL_HEURINIT()

    static SCIP_DECL_HEURINIT ( heurInitCoefdiving  )
    		static

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

    Definition at line 133 of file heur_coefdiving.c.

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

    ◆ SCIP_DECL_HEUREXIT()

    static SCIP_DECL_HEUREXIT ( heurExitCoefdiving  )
    		static

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

    Definition at line 153 of file heur_coefdiving.c.

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

    ◆ SCIP_DECL_HEUREXEC()

    static SCIP_DECL_HEUREXEC ( heurExecCoefdiving  )
    		static

    execution method of primal heuristic

    Definition at line 173 of file heur_coefdiving.c.

    References NULL, SCIP_CALL, SCIP_DIVECONTEXT_SINGLE, SCIP_OKAY, SCIPheurGetData(), SCIPheurGetDivesets(), SCIPheurGetNDivesets(), SCIPperformGenericDivingAlgorithm(), and SCIP_Diveset::sol.

    ◆ SCIP_DECL_DIVESETGETSCORE()

    static SCIP_DECL_DIVESETGETSCORE ( divesetGetScoreCoefdiving  )
    		static

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

    Definition at line 193 of file heur_coefdiving.c.

    References SCIP_Bool, SCIP_DIVETYPE_INTEGRALITY, SCIP_DIVETYPE_SOS1VARIABLE, SCIP_INVALIDDATA, SCIP_LOCKTYPE_MODEL, SCIP_OKAY, SCIP_PROBINGSCORE_PENALTYRATIO, SCIPABORT, SCIPdivesetGetRandnumgen(), SCIPerrorMessage, SCIPgetNLPRows(), SCIPisEQ(), SCIPisFeasNegative(), SCIPisFeasPositive(), SCIPrandomGetInt(), SCIPvarGetNLocksDownType(), SCIPvarGetNLocksUpType(), SCIPvarIsBinary(), SCIPvarMayRoundDown(), and SCIPvarMayRoundUp().