Scippy

    SCIP

    Solving Constraint Integer Programs

    Detailed Description

    LP diving heuristic that fixes variables with integral LP value.

    Author
    Tobias Achterberg

    Definition in file heur_intdiving.c.

    #include "blockmemshell/memory.h"
    #include "scip/heur_intdiving.h"
    #include "scip/pub_heur.h"
    #include "scip/pub_lp.h"
    #include "scip/pub_message.h"
    #include "scip/pub_var.h"
    #include "scip/scip_branch.h"
    #include "scip/scip_general.h"
    #include "scip/scip_heur.h"
    #include "scip/scip_lp.h"
    #include "scip/scip_mem.h"
    #include "scip/scip_message.h"
    #include "scip/scip_numerics.h"
    #include "scip/scip_param.h"
    #include "scip/scip_prob.h"
    #include "scip/scip_probing.h"
    #include "scip/scip_sol.h"
    #include "scip/scip_solvingstats.h"
    #include "scip/scip_tree.h"
    #include "scip/scip_var.h"
    #include <string.h>

    Go to the source code of this file.

    Macros

    #define HEUR_NAME   "intdiving"
     
    #define HEUR_DESC   "LP diving heuristic that fixes binary variables with large LP value to one"
     
    #define HEUR_DISPCHAR   SCIP_HEURDISPCHAR_DIVING
     
    #define HEUR_PRIORITY   -1003500
     
    #define HEUR_FREQ   -1
     
    #define HEUR_FREQOFS   9
     
    #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 SCIP_DECL_HEURCOPY (heurCopyIntdiving)
     
    static SCIP_DECL_HEURFREE (heurFreeIntdiving)
     
    static SCIP_DECL_HEURINIT (heurInitIntdiving)
     
    static SCIP_DECL_HEUREXIT (heurExitIntdiving)
     
    static SCIP_DECL_HEUREXEC (heurExecIntdiving)
     
    SCIP_RETCODE SCIPincludeHeurIntdiving (SCIP *scip)
     

    Macro Definition Documentation

    ◆ HEUR_NAME

    #define HEUR_NAME   "intdiving"

    Definition at line 55 of file heur_intdiving.c.

    ◆ HEUR_DESC

    #define HEUR_DESC   "LP diving heuristic that fixes binary variables with large LP value to one"

    Definition at line 56 of file heur_intdiving.c.

    ◆ HEUR_DISPCHAR

    #define HEUR_DISPCHAR   SCIP_HEURDISPCHAR_DIVING

    Definition at line 57 of file heur_intdiving.c.

    ◆ HEUR_PRIORITY

    #define HEUR_PRIORITY   -1003500

    Definition at line 58 of file heur_intdiving.c.

    ◆ HEUR_FREQ

    #define HEUR_FREQ   -1

    Definition at line 59 of file heur_intdiving.c.

    ◆ HEUR_FREQOFS

    #define HEUR_FREQOFS   9

    Definition at line 60 of file heur_intdiving.c.

    ◆ HEUR_MAXDEPTH

    #define HEUR_MAXDEPTH   -1

    Definition at line 61 of file heur_intdiving.c.

    ◆ HEUR_TIMING

    #define HEUR_TIMING   SCIP_HEURTIMING_AFTERLPPLUNGE

    Definition at line 62 of file heur_intdiving.c.

    ◆ HEUR_USESSUBSCIP

    #define HEUR_USESSUBSCIP   FALSE

    does the heuristic use a secondary SCIP instance?

    Definition at line 63 of file heur_intdiving.c.

    ◆ DEFAULT_MINRELDEPTH

    #define DEFAULT_MINRELDEPTH   0.0

    minimal relative depth to start diving

    Definition at line 70 of file heur_intdiving.c.

    ◆ DEFAULT_MAXRELDEPTH

    #define DEFAULT_MAXRELDEPTH   1.0

    maximal relative depth to start diving

    Definition at line 71 of file heur_intdiving.c.

    ◆ DEFAULT_MAXLPITERQUOT

    #define DEFAULT_MAXLPITERQUOT   0.05

    maximal fraction of diving LP iterations compared to node LP iterations

    Definition at line 72 of file heur_intdiving.c.

    ◆ DEFAULT_MAXLPITEROFS

    #define DEFAULT_MAXLPITEROFS   1000

    additional number of allowed LP iterations

    Definition at line 73 of file heur_intdiving.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 75 of file heur_intdiving.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 77 of file heur_intdiving.c.

    ◆ DEFAULT_MAXDIVEUBQUOTNOSOL

    #define DEFAULT_MAXDIVEUBQUOTNOSOL   0.1

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

    Definition at line 78 of file heur_intdiving.c.

    ◆ DEFAULT_MAXDIVEAVGQUOTNOSOL

    #define DEFAULT_MAXDIVEAVGQUOTNOSOL   0.0

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

    Definition at line 79 of file heur_intdiving.c.

    ◆ DEFAULT_BACKTRACK

    #define DEFAULT_BACKTRACK   TRUE

    use one level of backtracking if infeasibility is encountered?

    Definition at line 80 of file heur_intdiving.c.

    ◆ MINLPITER

    #define MINLPITER   10000

    minimal number of LP iterations allowed in each LP solving call

    Definition at line 82 of file heur_intdiving.c.

    Function Documentation

    ◆ SCIP_DECL_HEURCOPY()

    static SCIP_DECL_HEURCOPY ( heurCopyIntdiving  )
    static

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

    Definition at line 116 of file heur_intdiving.c.

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

    ◆ SCIP_DECL_HEURFREE()

    static SCIP_DECL_HEURFREE ( heurFreeIntdiving  )
    static

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

    Definition at line 130 of file heur_intdiving.c.

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

    ◆ SCIP_DECL_HEURINIT()

    static SCIP_DECL_HEURINIT ( heurInitIntdiving  )
    static

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

    Definition at line 150 of file heur_intdiving.c.

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

    ◆ SCIP_DECL_HEUREXIT()

    static SCIP_DECL_HEUREXIT ( heurExitIntdiving  )
    static

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

    Definition at line 174 of file heur_intdiving.c.

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

    ◆ SCIP_DECL_HEUREXEC()

    static SCIP_DECL_HEUREXEC ( heurExecIntdiving  )
    static

    execution method of primal heuristic

    Definition at line 194 of file heur_intdiving.c.

    References FALSE, HEUR_NAME, MAX, MIN, MINLPITER, NULL, SCIP_Bool, SCIP_CALL, SCIP_DELAYED, SCIP_DIDNOTFIND, SCIP_DIDNOTRUN, SCIP_FOUNDSOL, SCIP_INVALID, SCIP_Longint, SCIP_LONGINT_FORMAT, SCIP_LPSOLSTAT_INFEASIBLE, SCIP_LPSOLSTAT_OBJLIMIT, SCIP_LPSOLSTAT_OPTIMAL, SCIP_MAXTREEDEPTH, SCIP_OKAY, SCIP_Real, SCIP_VARSTATUS_COLUMN, SCIPallocBufferArray, SCIPbacktrackProbing(), SCIPceil(), SCIPcolGetNNonz(), SCIPdebugMsg, SCIPduplicateBufferArray, SCIPenableVarHistory(), SCIPendProbing(), SCIPfixVarProbing(), SCIPfloor(), SCIPfrac(), SCIPfreeBufferArray, SCIPgetAvgLowerbound(), SCIPgetCutoffbound(), SCIPgetDepth(), SCIPgetDualbound(), SCIPgetLastDivenode(), SCIPgetLowerbound(), SCIPgetLPObjval(), SCIPgetLPSolstat(), SCIPgetMaxDepth(), SCIPgetNContImplVars(), SCIPgetNContVars(), SCIPgetNLPIterations(), SCIPgetNNodeLPIterations(), SCIPgetNNodes(), SCIPgetNPseudoBranchCands(), SCIPgetNSolsFound(), SCIPgetNVars(), SCIPgetProbingDepth(), SCIPgetPseudoBranchCands(), SCIPgetSolOrigObj(), SCIPgetVarAvgInferenceScore(), SCIPhasCurrentNodeLP(), SCIPheurGetData(), SCIPheurGetName(), SCIPheurGetNBestSolsFound(), SCIPheurGetNCalls(), SCIPinfinity(), SCIPisEQ(), SCIPisFeasFracIntegral(), SCIPisFeasGT(), SCIPisFeasLE(), SCIPisFeasLT(), SCIPisGE(), SCIPisGT(), SCIPisLE(), SCIPisLPSolBasic(), SCIPisLT(), SCIPisObjIntegral(), SCIPisStopped(), SCIPisZero(), SCIPlinkLPSol(), SCIPnewProbingNode(), SCIPpropagateProbing(), SCIPretransformObj(), SCIProundSol(), SCIPsolveProbingLP(), SCIPstartProbing(), SCIPtrySol(), SCIPvarGetCol(), SCIPvarGetLbLocal(), SCIPvarGetLPSol(), SCIPvarGetName(), SCIPvarGetNCliques(), SCIPvarGetNImpls(), SCIPvarGetStatus(), SCIPvarGetUbLocal(), SCIPvarIsBinary(), SCIPvarIsIntegral(), SCIPwarningMessage(), and TRUE.