heur_simplerounding.c File Reference

Detailed Description

simple and fast LP rounding heuristic

Author

Tobias Achterberg

Marc Pfetsch

The heuristic also tries to round relaxation solutions if available.

Definition in file heur_simplerounding.c.

#include "blockmemshell/memory.h"
#include "scip/heur_simplerounding.h"
#include "scip/pub_heur.h"
#include "scip/pub_message.h"
#include "scip/pub_var.h"
#include "scip/scip_branch.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_sol.h"
#include "scip/scip_solvingstats.h"
#include "scip/scip_var.h"
#include <string.h>

Go to the source code of this file.

Macros
#define	HEUR_NAME   "simplerounding"
#define	HEUR_DESC   "simple and fast LP rounding heuristic"
#define	HEUR_DISPCHAR   SCIP_HEURDISPCHAR_ROUNDING
#define	HEUR_PRIORITY   -30
#define	HEUR_FREQ   1
#define	HEUR_FREQOFS   0
#define	HEUR_MAXDEPTH   -1
#define	HEUR_TIMING   SCIP_HEURTIMING_DURINGLPLOOP | SCIP_HEURTIMING_DURINGPRICINGLOOP
#define	HEUR_USESSUBSCIP   FALSE
#define	DEFAULT_ONCEPERNODE   FALSE

Functions
static SCIP_RETCODE	performSimpleRounding (SCIP *scip, SCIP_SOL *sol, SCIP_VAR **cands, SCIP_Real *candssol, int ncands, SCIP_RESULT *result)
static SCIP_RETCODE	performLPSimpleRounding (SCIP *scip, SCIP_HEURDATA *heurdata, SCIP_HEURTIMING heurtiming, SCIP_RESULT *result)
static SCIP_RETCODE	performRelaxSimpleRounding (SCIP *scip, SCIP_HEURDATA *heurdata, SCIP_RESULT *result)
static	SCIP_DECL_HEURCOPY (heurCopySimplerounding)
static	SCIP_DECL_HEURFREE (heurFreeSimplerounding)
static	SCIP_DECL_HEURINIT (heurInitSimplerounding)
static	SCIP_DECL_HEUREXIT (heurExitSimplerounding)
static	SCIP_DECL_HEURINITSOL (heurInitsolSimplerounding)
static	SCIP_DECL_HEUREXITSOL (heurExitsolSimplerounding)
static	SCIP_DECL_HEUREXEC (heurExecSimplerounding)
SCIP_RETCODE	SCIPincludeHeurSimplerounding (SCIP *scip)

Macro Definition Documentation

HEUR_NAME

#define HEUR_NAME   "simplerounding"

Definition at line 54 of file heur_simplerounding.c.

HEUR_DESC

#define HEUR_DESC   "simple and fast LP rounding heuristic"

Definition at line 55 of file heur_simplerounding.c.

HEUR_DISPCHAR

#define HEUR_DISPCHAR   SCIP_HEURDISPCHAR_ROUNDING

Definition at line 56 of file heur_simplerounding.c.

HEUR_PRIORITY

#define HEUR_PRIORITY   -30

Definition at line 57 of file heur_simplerounding.c.

HEUR_FREQ

#define HEUR_FREQ   1

Definition at line 58 of file heur_simplerounding.c.

HEUR_FREQOFS

#define HEUR_FREQOFS   0

Definition at line 59 of file heur_simplerounding.c.

HEUR_MAXDEPTH

#define HEUR_MAXDEPTH   -1

Definition at line 60 of file heur_simplerounding.c.

HEUR_TIMING

#define HEUR_TIMING   SCIP_HEURTIMING_DURINGLPLOOP | SCIP_HEURTIMING_DURINGPRICINGLOOP

Definition at line 61 of file heur_simplerounding.c.

HEUR_USESSUBSCIP

#define HEUR_USESSUBSCIP   FALSE

does the heuristic use a secondary SCIP instance?

Definition at line 62 of file heur_simplerounding.c.

DEFAULT_ONCEPERNODE

#define DEFAULT_ONCEPERNODE   FALSE

should the heuristic only be called once per node?

Definition at line 64 of file heur_simplerounding.c.

Function Documentation

performSimpleRounding()

static SCIP_RETCODE performSimpleRounding ( SCIP *  scip, SCIP_SOL *  sol, SCIP_VAR **  cands, SCIP_Real *  candssol, int  ncands, SCIP_RESULT *  result  )

static

perform rounding

Parameters

scip	SCIP main data structure
sol	solution to round
cands	candidate variables
candssol	solutions of candidate variables
ncands	number of candidates
result	pointer to store the result of the heuristic call

Definition at line 82 of file heur_simplerounding.c.

References FALSE, NULL, SCIP_Bool, SCIP_CALL, SCIP_FOUNDSOL, SCIP_OKAY, SCIP_Real, SCIP_VARSTATUS_COLUMN, SCIPadjustImplicitSolVals(), SCIPallColsInLP(), SCIPdebugMsg, SCIPfeasCeil(), SCIPfeasFloor(), SCIPisFeasIntegral(), SCIPprintSol(), SCIPsetSolVal(), SCIPtrySol(), SCIPvarGetName(), SCIPvarGetObj(), SCIPvarGetStatus(), SCIPvarIsImpliedIntegral(), SCIPvarMayRoundDown(), SCIPvarMayRoundUp(), and TRUE.

Referenced by performLPSimpleRounding(), and performRelaxSimpleRounding().

performLPSimpleRounding()

static SCIP_RETCODE performLPSimpleRounding ( SCIP *  scip, SCIP_HEURDATA *  heurdata, SCIP_HEURTIMING  heurtiming, SCIP_RESULT *  result  )

static

perform LP-rounding

Parameters

scip	SCIP main data structure
heurdata	heuristic data
heurtiming	heuristic timing mask
result	pointer to store the result of the heuristic call

Definition at line 185 of file heur_simplerounding.c.

References NULL, performSimpleRounding(), SCIP_CALL, SCIP_HEURTIMING_DURINGPRICINGLOOP, SCIP_Longint, SCIP_LPSOLSTAT_OPTIMAL, SCIP_OKAY, SCIP_Real, SCIPdebugMsg, SCIPgetCutoffbound(), SCIPgetLPBranchCands(), SCIPgetLPObjval(), SCIPgetLPSolstat(), SCIPgetNLPs(), SCIPisGE(), and SCIPlinkLPSol().

Referenced by SCIP_DECL_HEUREXEC().

performRelaxSimpleRounding()

static SCIP_RETCODE performRelaxSimpleRounding ( SCIP *  scip, SCIP_HEURDATA *  heurdata, SCIP_RESULT *  result  )

static

perform relaxation solution rounding

Parameters

scip	SCIP main data structure
heurdata	heuristic data
result	pointer to store the result of the heuristic call

Definition at line 245 of file heur_simplerounding.c.

References NULL, performSimpleRounding(), SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPdebugMsg, SCIPfreeBufferArray, SCIPgetRelaxSolVal(), SCIPgetVarsData(), SCIPisFeasIntegral(), SCIPisRelaxSolValid(), and SCIPlinkRelaxSol().

Referenced by SCIP_DECL_HEUREXEC().

SCIP_DECL_HEURCOPY()

static SCIP_DECL_HEURCOPY ( heurCopySimplerounding  )

static

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

Definition at line 338 of file heur_simplerounding.c.

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

SCIP_DECL_HEURFREE()

static SCIP_DECL_HEURFREE ( heurFreeSimplerounding  )

static

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

Definition at line 352 of file heur_simplerounding.c.

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

SCIP_DECL_HEURINIT()

static SCIP_DECL_HEURINIT ( heurInitSimplerounding  )

static

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

Definition at line 372 of file heur_simplerounding.c.

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

SCIP_DECL_HEUREXIT()

static SCIP_DECL_HEUREXIT ( heurExitSimplerounding  )

static

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

Definition at line 391 of file heur_simplerounding.c.

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

SCIP_DECL_HEURINITSOL()

static SCIP_DECL_HEURINITSOL ( heurInitsolSimplerounding  )

static

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

Definition at line 408 of file heur_simplerounding.c.

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

SCIP_DECL_HEUREXITSOL()

static SCIP_DECL_HEUREXITSOL ( heurExitsolSimplerounding  )

static

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

Definition at line 428 of file heur_simplerounding.c.

References HEUR_TIMING, SCIP_OKAY, and SCIPheurSetTimingmask().

SCIP_DECL_HEUREXEC()

static SCIP_DECL_HEUREXEC ( heurExecSimplerounding  )

static

execution method of primal heuristic

Definition at line 439 of file heur_simplerounding.c.

References HEUR_NAME, NULL, performLPSimpleRounding(), performRelaxSimpleRounding(), SCIP_CALL, SCIP_DIDNOTFIND, SCIP_DIDNOTRUN, SCIP_HEURTIMING_DURINGPRICINGLOOP, SCIP_LPSOLSTAT_OPTIMAL, SCIP_OKAY, SCIPgetCutoffbound(), SCIPgetLPObjval(), SCIPgetLPSolstat(), SCIPgetNBinVars(), SCIPgetNIntVars(), SCIPgetNLPs(), SCIPgetVars(), SCIPhasCurrentNodeLP(), SCIPheurGetData(), SCIPheurGetName(), SCIPisGE(), SCIPisRelaxSolValid(), SCIPvarMayRoundDown(), and SCIPvarMayRoundUp().