heur_indicator.c File Reference

Detailed Description

handle partial solutions for linear problems with indicators and otherwise continuous variables

Author

Marc Pfetsch

For linear problems with indicators and otherwise continuous variables, the indicator constraint handler can produce partial solutions, i.e., values for the indicator variables. This partial solution can be passed to this heuristic, which then fixes these values and solves an LP. Additionally a local search for a better solution is added.

Definition in file heur_indicator.c.

#include "blockmemshell/memory.h"
#include "scip/cons_indicator.h"
#include "scip/heur_indicator.h"
#include "scip/pub_cons.h"
#include "scip/pub_heur.h"
#include "scip/pub_message.h"
#include "scip/pub_sol.h"
#include "scip/pub_var.h"
#include "scip/scip_cons.h"
#include "scip/scip_copy.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_tree.h"
#include <string.h>

Go to the source code of this file.

Macros
#define	HEUR_NAME   "indicator"
#define	HEUR_DESC   "indicator heuristic to create feasible solutions from values for indicator variables"
#define	HEUR_DISPCHAR   SCIP_HEURDISPCHAR_LNS
#define	HEUR_PRIORITY   -20200
#define	HEUR_FREQ   1
#define	HEUR_FREQOFS   0
#define	HEUR_MAXDEPTH   -1
#define	HEUR_TIMING   SCIP_HEURTIMING_DURINGLPLOOP
#define	HEUR_USESSUBSCIP   FALSE
#define	DEFAULT_ONEOPT   FALSE
#define	DEFAULT_IMPROVESOLS   FALSE

Functions
static SCIP_RETCODE	tryOneOpt (SCIP *scip, SCIP_HEUR *heur, SCIP_HEURDATA *heurdata, int nindconss, SCIP_CONS **indconss, SCIP_Bool *solcand, int *nfoundsols)
static SCIP_RETCODE	trySolCandidate (SCIP *scip, SCIP_HEUR *heur, SCIP_HEURDATA *heurdata, int nindconss, SCIP_CONS **indconss, SCIP_Bool *solcand, int *nfoundsols)
static	SCIP_DECL_HEURCOPY (heurCopyIndicator)
static	SCIP_DECL_HEURINITSOL (heurInitsolIndicator)
static	SCIP_DECL_HEUREXITSOL (heurExitsolIndicator)
static	SCIP_DECL_HEURFREE (heurFreeIndicator)
static	SCIP_DECL_HEUREXEC (heurExecIndicator)
SCIP_RETCODE	SCIPincludeHeurIndicator (SCIP *scip)
SCIP_RETCODE	SCIPheurPassIndicator (SCIP *scip, SCIP_HEUR *heur, int nindconss, SCIP_CONS **indconss, SCIP_Bool *solcand, SCIP_Real obj)

Macro Definition Documentation

HEUR_NAME

#define HEUR_NAME   "indicator"

Definition at line 60 of file heur_indicator.c.

HEUR_DESC

#define HEUR_DESC   "indicator heuristic to create feasible solutions from values for indicator variables"

Definition at line 61 of file heur_indicator.c.

HEUR_DISPCHAR

#define HEUR_DISPCHAR   SCIP_HEURDISPCHAR_LNS

Definition at line 62 of file heur_indicator.c.

HEUR_PRIORITY

#define HEUR_PRIORITY   -20200

Definition at line 63 of file heur_indicator.c.

HEUR_FREQ

#define HEUR_FREQ   1

Definition at line 64 of file heur_indicator.c.

HEUR_FREQOFS

#define HEUR_FREQOFS   0

Definition at line 65 of file heur_indicator.c.

HEUR_MAXDEPTH

#define HEUR_MAXDEPTH   -1

Definition at line 66 of file heur_indicator.c.

HEUR_TIMING

#define HEUR_TIMING   SCIP_HEURTIMING_DURINGLPLOOP

Definition at line 67 of file heur_indicator.c.

HEUR_USESSUBSCIP

#define HEUR_USESSUBSCIP   FALSE

does the heuristic use a secondary SCIP instance?

Definition at line 68 of file heur_indicator.c.

DEFAULT_ONEOPT

#define DEFAULT_ONEOPT   FALSE

whether the one-opt heuristic should be started

Definition at line 70 of file heur_indicator.c.

DEFAULT_IMPROVESOLS

#define DEFAULT_IMPROVESOLS   FALSE

Try to improve other solutions by one-opt?

Definition at line 71 of file heur_indicator.c.

Function Documentation

tryOneOpt()

static SCIP_RETCODE tryOneOpt ( SCIP *  scip, SCIP_HEUR *  heur, SCIP_HEURDATA *  heurdata, int  nindconss, SCIP_CONS **  indconss, SCIP_Bool *  solcand, int *  nfoundsols  )

static

try one-opt on given solution

Parameters

scip	SCIP data structure
heur	indicator heuristic
heurdata	heuristic data
nindconss	number of indicator constraints
indconss	indicator constraints
solcand	values for indicator variables in partial solution
nfoundsols	number of solutions found

Definition at line 94 of file heur_indicator.c.

References FALSE, NULL, SCIP_Bool, SCIP_CALL, SCIP_LPSOLSTAT_OPTIMAL, SCIP_MAXTREEDEPTH, SCIP_OKAY, SCIPbacktrackProbing(), SCIPchgVarLbProbing(), SCIPchgVarUbProbing(), SCIPconsIsActive(), SCIPcreateSol(), SCIPdebugMsg, SCIPendProbing(), SCIPgetBinaryVarIndicator(), SCIPgetDepth(), SCIPgetLPSolstat(), SCIPgetSolTransObj(), SCIPisStopped(), SCIPlinkLPSol(), SCIPnewProbingNode(), SCIPpropagateProbing(), SCIPsolveProbingLP(), SCIPstartProbing(), SCIPtrySolFree(), SCIPvarGetLbLocal(), SCIPvarGetUbLocal(), and TRUE.

Referenced by SCIP_DECL_HEUREXEC(), and trySolCandidate().

trySolCandidate()

static SCIP_RETCODE trySolCandidate ( SCIP *  scip, SCIP_HEUR *  heur, SCIP_HEURDATA *  heurdata, int  nindconss, SCIP_CONS **  indconss, SCIP_Bool *  solcand, int *  nfoundsols  )

static

try given solution

Parameters

scip	SCIP data structure
heur	indicator heuristic
heurdata	heuristic data
nindconss	number of indicator constraints
indconss	indicator constraints
solcand	values for indicator variables in partial solution
nfoundsols	number of solutions found

Definition at line 231 of file heur_indicator.c.

References FALSE, NULL, SCIP_Bool, SCIP_CALL, SCIP_LPSOLSTAT_OPTIMAL, SCIP_MAXTREEDEPTH, SCIP_OKAY, SCIPchgVarLbProbing(), SCIPchgVarUbProbing(), SCIPconsIsActive(), SCIPcreateSol(), SCIPdebugMsg, SCIPendProbing(), SCIPgetBinaryVarIndicator(), SCIPgetDepth(), SCIPgetLPSolstat(), SCIPgetSolTransObj(), SCIPlinkLPSol(), SCIPnewProbingNode(), SCIPprintSol(), SCIPpropagateProbing(), SCIPsolveProbingLP(), SCIPstartProbing(), SCIPtrySolFree(), SCIPvarGetLbLocal(), SCIPvarGetUbLocal(), TRUE, and tryOneOpt().

Referenced by SCIP_DECL_HEUREXEC().

SCIP_DECL_HEURCOPY()

static SCIP_DECL_HEURCOPY ( heurCopyIndicator  )

static

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

Definition at line 373 of file heur_indicator.c.

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

SCIP_DECL_HEURINITSOL()

static SCIP_DECL_HEURINITSOL ( heurInitsolIndicator  )

static

solving process initialization method of primal heuristic (called when branch and bound process is about to begin)

Definition at line 387 of file heur_indicator.c.

References HEUR_NAME, NULL, SCIP_HEURTIMING_NONE, SCIP_OKAY, SCIPconshdlrGetNConss(), SCIPfindConshdlr(), SCIPgetSubscipDepth(), SCIPheurGetData(), SCIPheurGetName(), SCIPheurGetTimingmask(), and SCIPheurSetTimingmask().

SCIP_DECL_HEUREXITSOL()

static SCIP_DECL_HEUREXITSOL ( heurExitsolIndicator  )

static

solving process deinitialization method of primal heuristic (called before branch and bound process data is freed)

Definition at line 413 of file heur_indicator.c.

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

SCIP_DECL_HEURFREE()

static SCIP_DECL_HEURFREE ( heurFreeIndicator  )

static

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

Definition at line 432 of file heur_indicator.c.

References NULL, SCIP_OKAY, SCIPfreeBlockMemory, SCIPfreeBlockMemoryArrayNull, SCIPheurGetData(), and SCIPheurSetData().

SCIP_DECL_HEUREXEC()

static SCIP_DECL_HEUREXEC ( heurExecIndicator  )

static

execution method of primal heuristic

Definition at line 456 of file heur_indicator.c.

References FALSE, NULL, SCIP_Bool, SCIP_CALL, SCIP_DIDNOTFIND, SCIP_DIDNOTRUN, SCIP_FOUNDSOL, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPconshdlrGetConss(), SCIPconshdlrGetNConss(), SCIPconsIsActive(), SCIPdebugMsg, SCIPfreeBlockMemoryArray, SCIPfreeBufferArray, SCIPgetBestSol(), SCIPgetBinaryVarIndicator(), SCIPgetNBinImplVars(), SCIPgetNBinVars(), SCIPgetNIntImplVars(), SCIPgetNIntVars(), SCIPgetSolOrigObj(), SCIPgetSolVal(), SCIPheurGetData(), SCIPisFeasIntegral(), SCIPsolGetHeur(), TRUE, tryOneOpt(), and trySolCandidate().