Scippy

SCIP

Solving Constraint Integer Programs

heur_clique.c File Reference

Detailed Description

LNS heuristic using a clique partition to restrict the search neighborhood.

clique primal heuristic

Author
Stefan Heinz
Michael Winkler

Definition in file heur_clique.c.

#include <assert.h>
#include <string.h>
#include "scip/scip.h"
#include "scip/heur_clique.h"
#include "scip/cons_logicor.h"

Go to the source code of this file.

Macros

#define HEUR_NAME   "clique"
 
#define HEUR_DESC   "LNS heuristic using a clique partition to restrict the search neighborhood"
 
#define HEUR_DISPCHAR   'Q'
 
#define HEUR_PRIORITY   -1000500
 
#define HEUR_FREQ   -1
 
#define HEUR_FREQOFS   0
 
#define HEUR_MAXDEPTH   -1
 
#define HEUR_TIMING   SCIP_HEURTIMING_BEFORENODE
 
#define HEUR_USESSUBSCIP   TRUE
 
#define DEFAULT_MAXNODES   5000LL
 
#define DEFAULT_MINFIXINGRATE   0.5
 
#define DEFAULT_MINIMPROVE   0.01
 
#define DEFAULT_MINNODES   500LL
 
#define DEFAULT_NODESOFS   500LL
 
#define DEFAULT_NODESQUOT   0.1
 
#define DEFAULT_MAXPROPROUNDS   2
 
#define DEFAULT_INITSEED   0
 
#define DEFAULT_MULTIPLIER   1.1
 
#define DEFAULT_COPYCUTS   TRUE
 

Functions

static SCIP_DECL_SORTPTRCOMP (varObjSort)
 
static SCIP_RETCODE stableSortBinvars (SCIP *scip, SCIP_VAR **binvars, int nbinvars, int *cliquepartition, int ncliques)
 
static SCIP_RETCODE applyCliqueFixings (SCIP *scip, SCIP_HEURDATA *heurdata, SCIP_VAR **binvars, int nbinvars, int *cliquepartition, int ncliques, SCIP_VAR **onefixvars, int *nonefixvars, SCIP_SOL *sol, int *probingdepthofonefix, SCIP_Bool *cutoff, SCIP_RESULT *result)
 
static SCIP_RETCODE createNewSol (SCIP *scip, SCIP *subscip, SCIP_VAR **subvars, SCIP_SOL *newsol, SCIP_SOL *subsol, SCIP_Bool *success)
 
static SCIP_DECL_HEURCOPY (heurCopyClique)
 
static SCIP_DECL_HEURFREE (heurFreeClique)
 
static SCIP_DECL_HEURINIT (heurInitClique)
 
static SCIP_DECL_HEUREXEC (heurExecClique)
 
SCIP_RETCODE SCIPincludeHeurClique (SCIP *scip)
 

Macro Definition Documentation

#define HEUR_NAME   "clique"
#define HEUR_DESC   "LNS heuristic using a clique partition to restrict the search neighborhood"

Definition at line 34 of file heur_clique.c.

Referenced by SCIPincludeHeurClique().

#define HEUR_DISPCHAR   'Q'

Definition at line 35 of file heur_clique.c.

Referenced by SCIPincludeHeurClique().

#define HEUR_PRIORITY   -1000500

Definition at line 36 of file heur_clique.c.

Referenced by SCIPincludeHeurClique().

#define HEUR_FREQ   -1

Definition at line 37 of file heur_clique.c.

Referenced by SCIPincludeHeurClique().

#define HEUR_FREQOFS   0

Definition at line 38 of file heur_clique.c.

Referenced by SCIPincludeHeurClique().

#define HEUR_MAXDEPTH   -1

Definition at line 39 of file heur_clique.c.

Referenced by SCIPincludeHeurClique().

#define HEUR_TIMING   SCIP_HEURTIMING_BEFORENODE

Definition at line 40 of file heur_clique.c.

Referenced by SCIPincludeHeurClique().

#define HEUR_USESSUBSCIP   TRUE

does the heuristic use a secondary SCIP instance?

Definition at line 41 of file heur_clique.c.

Referenced by SCIPincludeHeurClique().

#define DEFAULT_MAXNODES   5000LL

maximum number of nodes to regard in the subproblem

Definition at line 43 of file heur_clique.c.

Referenced by SCIPincludeHeurClique().

#define DEFAULT_MINFIXINGRATE   0.5

minimum percentage of integer variables that have to be fixed

Definition at line 44 of file heur_clique.c.

Referenced by SCIPincludeHeurClique().

#define DEFAULT_MINIMPROVE   0.01

factor by which clique heuristic should at least improve the incumbent

Definition at line 45 of file heur_clique.c.

Referenced by SCIPincludeHeurClique().

#define DEFAULT_MINNODES   500LL

minimum number of nodes to regard in the subproblem

Definition at line 48 of file heur_clique.c.

Referenced by SCIPincludeHeurClique().

#define DEFAULT_NODESOFS   500LL

number of nodes added to the contingent of the total nodes

Definition at line 49 of file heur_clique.c.

Referenced by SCIPincludeHeurClique().

#define DEFAULT_NODESQUOT   0.1

subproblem nodes in relation to nodes of the original problem

Definition at line 50 of file heur_clique.c.

Referenced by SCIPincludeHeurClique().

#define DEFAULT_MAXPROPROUNDS   2

maximum number of propagation rounds during probing

Definition at line 51 of file heur_clique.c.

Referenced by SCIPincludeHeurClique().

#define DEFAULT_INITSEED   0

random seed value to initialize the random permutation value for variables

Definition at line 52 of file heur_clique.c.

Referenced by SCIPincludeHeurClique().

#define DEFAULT_MULTIPLIER   1.1

value to increase node number to determine the next run

Definition at line 55 of file heur_clique.c.

Referenced by SCIPincludeHeurClique().

#define DEFAULT_COPYCUTS   TRUE

should all active cuts from the cutpool of the original scip be copied to constraints of the subscip

Definition at line 56 of file heur_clique.c.

Referenced by SCIPincludeHeurClique().

Function Documentation

static SCIP_DECL_SORTPTRCOMP ( varObjSort  )
static

comparison method for sorting variables by non-decreasing index

Definition at line 91 of file heur_clique.c.

References NULL, and SCIPvarGetObj().

static SCIP_RETCODE stableSortBinvars ( SCIP scip,
SCIP_VAR **  binvars,
int  nbinvars,
int *  cliquepartition,
int  ncliques 
)
static

sort the binary variable array w.r.t. the clique partition; thereby ensure the current order within the cliques are not changed

Parameters
scipSCIP data structure
binvarsarray of binary variables to sort
nbinvarsnumber of binary variables
cliquepartitionclique partition to use
ncliquesnumber of cliques

Definition at line 114 of file heur_clique.c.

References BMSclearMemoryArray, BMScopyMemoryArray, NULL, SCIP_CALL, SCIP_OKAY, SCIPallocBufferArray, SCIPfreeBufferArray, SCIPvarGetName(), and SCIPvarGetObj().

Referenced by SCIP_DECL_HEUREXEC().

static SCIP_RETCODE applyCliqueFixings ( SCIP scip,
SCIP_HEURDATA heurdata,
SCIP_VAR **  binvars,
int  nbinvars,
int *  cliquepartition,
int  ncliques,
SCIP_VAR **  onefixvars,
int *  nonefixvars,
SCIP_SOL sol,
int *  probingdepthofonefix,
SCIP_Bool cutoff,
SCIP_RESULT result 
)
static

apply clique fixing using probing

Parameters
sciporiginal SCIP data structure
heurdatastructure containing heurdata
binvarsbinary variables order w.r.t. to clique partition
nbinvarsnumber of binary variables
cliquepartitionclique partition of all binary variables
ncliquesnumber of cliques
onefixvarsarray to store all variables which are stored to one
nonefixvarspointer to store the number of variables fixed to one
solworking solution
probingdepthofonefixpointer to store in which depth the last fixing to was applied
cutoffpointer to store whether the propagation stopped with infeasibility
resultpointer to store the result (solution found)

Definition at line 243 of file heur_clique.c.

References FALSE, NULL, SCIP_Bool, SCIP_CALL, SCIP_FOUNDSOL, SCIP_OKAY, SCIPdebugMessage, SCIPfixVarProbing(), SCIPgetProbingDepth(), SCIPgetSolOrigObj(), SCIPisStopped(), SCIPlinkCurrentSol(), SCIPnewProbingNode(), SCIPpropagateProbing(), SCIProundSol(), SCIPtrySol(), SCIPvarGetLbLocal(), SCIPvarGetName(), SCIPvarGetUbLocal(), and TRUE.

Referenced by SCIP_DECL_HEUREXEC().

static SCIP_RETCODE createNewSol ( SCIP scip,
SCIP subscip,
SCIP_VAR **  subvars,
SCIP_SOL newsol,
SCIP_SOL subsol,
SCIP_Bool success 
)
static

creates a new solution for the original problem by copying the solution of the subproblem

Parameters
sciporiginal SCIP data structure
subscipSCIP structure of the subproblem
subvarsthe variables of the subproblem
newsolworking solution
subsolsolution of the subproblem
successused to store whether new solution was found or not

Definition at line 404 of file heur_clique.c.

References FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPfreeBufferArray, SCIPgetNOrigVars(), SCIPgetSolVals(), SCIPgetVarsData(), SCIPsetSolVals(), SCIPtrySol(), and TRUE.

Referenced by SCIP_DECL_HEUREXEC().

static SCIP_DECL_HEURCOPY ( heurCopyClique  )
static

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

Definition at line 452 of file heur_clique.c.

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

static SCIP_DECL_HEURFREE ( heurFreeClique  )
static

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

Definition at line 466 of file heur_clique.c.

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

static SCIP_DECL_HEURINIT ( heurInitClique  )
static

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

Definition at line 487 of file heur_clique.c.

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

static SCIP_DECL_HEUREXEC ( heurExecClique  )
static

execution method of primal heuristic

Definition at line 510 of file heur_clique.c.

References applyCliqueFixings(), createNewSol(), FALSE, HEUR_NAME, MIN, NULL, SCIP_Bool, SCIP_CALL, SCIP_DIDNOTFIND, SCIP_DIDNOTRUN, SCIP_FOUNDSOL, SCIP_Longint, SCIP_LPSOLSTAT_ERROR, SCIP_LPSOLSTAT_INFEASIBLE, SCIP_LPSOLSTAT_OBJLIMIT, SCIP_LPSOLSTAT_OPTIMAL, SCIP_MAXSTRLEN, SCIP_OKAY, SCIP_PARAMSETTING_FAST, SCIP_PARAMSETTING_OFF, SCIP_Real, SCIP_STATUS_INFEASIBLE, SCIPaddConsNode(), SCIPallocBufferArray, SCIPbacktrackProbing(), SCIPblkmem(), SCIPcalcCliquePartition(), SCIPcalcHashtableSize(), SCIPceil(), SCIPconstructLP(), SCIPcopy(), SCIPcopyCuts(), SCIPcreate(), SCIPcreateConsLogicor(), SCIPcreateSol(), SCIPdebug, SCIPdebugMessage, SCIPdebugPrintCons, SCIPduplicateBufferArray, SCIPendProbing(), SCIPfindConshdlr(), SCIPfixVarProbing(), SCIPflushLP(), SCIPfree(), SCIPfreeBufferArray, SCIPfreeSol(), SCIPgetBoolParam(), SCIPgetCurrentNode(), SCIPgetLowerbound(), SCIPgetLPSolstat(), SCIPgetMemExternEstim(), SCIPgetMemUsed(), SCIPgetNCliques(), SCIPgetNConss(), SCIPgetNegatedVars(), SCIPgetNImplications(), SCIPgetNLPIterations(), SCIPgetNNodes(), SCIPgetNSols(), SCIPgetNVars(), SCIPgetRealParam(), SCIPgetSolOrigObj(), SCIPgetSols(), SCIPgetSolvingTime(), SCIPgetStatus(), SCIPgetUpperbound(), SCIPgetVarsData(), SCIPhasCurrentNodeLP(), SCIPhashmapCreate(), SCIPhashmapFree(), SCIPhashmapGetImage(), SCIPheurGetData(), SCIPheurGetName(), SCIPheurGetNBestSolsFound(), SCIPheurGetNCalls(), SCIPinfinity(), SCIPinProbing(), SCIPisInfinity(), SCIPisLPConstructed(), SCIPisParamFixed(), SCIPisStopped(), SCIPlinkLPSol(), SCIPpermuteArray(), SCIPpresolve(), SCIPprintSol(), SCIPprintStatistics(), SCIPpropagateProbing(), SCIPreleaseCons(), SCIProundSol(), SCIPsetBoolParam(), SCIPsetIntParam(), SCIPsetLongintParam(), SCIPsetObjlimit(), SCIPsetPresolving(), SCIPsetRealParam(), SCIPsetSeparating(), SCIPsetSubscipsOff(), SCIPsnprintf(), SCIPsolve(), SCIPsolveProbingLP(), SCIPsortPtr(), SCIPstartProbing(), SCIPsumepsilon(), SCIPtrySol(), SCIPwarningMessage(), stableSortBinvars(), and TRUE.