Detailed Description

OFINS - Objective Function Induced Neighborhood Search - a primal heuristic for reoptimization.

Author: Jakob Witzig

Definition in file heur_ofins.c.

#include "blockmemshell/memory.h"
#include "scip/heuristics.h"
#include "scip/heur_ofins.h"
#include "scip/pub_event.h"
#include "scip/pub_heur.h"
#include "scip/pub_message.h"
#include "scip/pub_misc.h"
#include "scip/pub_sol.h"
#include "scip/pub_var.h"
#include "scip/scip_branch.h"
#include "scip/scip_copy.h"
#include "scip/scip_event.h"
#include "scip/scip_general.h"
#include "scip/scip_heur.h"
#include "scip/scip_mem.h"
#include "scip/scip_message.h"
#include "scip/scip_nodesel.h"
#include "scip/scip_numerics.h"
#include "scip/scip_param.h"
#include "scip/scip_prob.h"
#include "scip/scip_sol.h"
#include "scip/scip_solve.h"
#include "scip/scip_solvingstats.h"
#include "scip/scip_timing.h"
#include <string.h>

Go to the source code of this file.

Macros
#define	HEUR_NAME "ofins"

#define	HEUR_DESC "primal heuristic for reoptimization, objective function induced neighborhood search"

#define	HEUR_DISPCHAR SCIP_HEURDISPCHAR_LNS

#define	HEUR_PRIORITY 60000

#define	HEUR_FREQ 0

#define	HEUR_FREQOFS 0

#define	HEUR_MAXDEPTH 0

#define	HEUR_TIMING SCIP_HEURTIMING_BEFORENODE

#define	HEUR_USESSUBSCIP TRUE

#define	DEFAULT_MAXNODES 5000LL

#define	DEFAULT_MAXCHGRATE 0.50

#define	DEFAULT_COPYCUTS TRUE

#define	DEFAULT_MAXCHANGE 0.04

#define	DEFAULT_MINIMPROVE 0.01

#define	DEFAULT_ADDALLSOLS FALSE

#define	DEFAULT_MINNODES 50LL

#define	DEFAULT_NODESOFS 500LL

#define	DEFAULT_NODESQUOT 0.1

#define	DEFAULT_LPLIMFAC 2.0

#define	EVENTHDLR_NAME "Ofins"

#define	EVENTHDLR_DESC "LP event handler for " HEUR_NAME " heuristic"

Functions
static	SCIP_DECL_EVENTEXEC (eventExecOfins)

static SCIP_RETCODE	setupAndSolve (SCIP scip, SCIP subscip, SCIP_HEUR heur, SCIP_HEURDATA heurdata, SCIP_RESULT result, SCIP_Longint nstallnodes, SCIP_Bool chgcoeffs)

static SCIP_RETCODE	applyOfins (SCIP scip, SCIP_HEUR heur, SCIP_HEURDATA heurdata, SCIP_RESULT result, SCIP_Longint nstallnodes, SCIP_Bool *chgcoeffs)

static	SCIP_DECL_HEURCOPY (heurCopyOfins)

static	SCIP_DECL_HEURFREE (heurFreeOfins)

static	SCIP_DECL_HEUREXEC (heurExecOfins)

SCIP_RETCODE	SCIPincludeHeurOfins (SCIP *scip)

Macro Definition Documentation

◆ HEUR_NAME

#define HEUR_NAME "ofins"

Definition at line 59 of file heur_ofins.c.

◆ HEUR_DESC

#define HEUR_DESC "primal heuristic for reoptimization, objective function induced neighborhood search"

Definition at line 60 of file heur_ofins.c.

◆ HEUR_DISPCHAR

#define HEUR_DISPCHAR SCIP_HEURDISPCHAR_LNS

Definition at line 61 of file heur_ofins.c.

◆ HEUR_PRIORITY

#define HEUR_PRIORITY 60000

Definition at line 62 of file heur_ofins.c.

◆ HEUR_FREQ

#define HEUR_FREQ 0

Definition at line 63 of file heur_ofins.c.

◆ HEUR_FREQOFS

#define HEUR_FREQOFS 0

Definition at line 64 of file heur_ofins.c.

◆ HEUR_MAXDEPTH

#define HEUR_MAXDEPTH 0

Definition at line 65 of file heur_ofins.c.

◆ HEUR_TIMING

#define HEUR_TIMING SCIP_HEURTIMING_BEFORENODE

Definition at line 66 of file heur_ofins.c.

◆ HEUR_USESSUBSCIP

#define HEUR_USESSUBSCIP TRUE

does the heuristic use a secondary SCIP instance?

Definition at line 67 of file heur_ofins.c.

◆ DEFAULT_MAXNODES

#define DEFAULT_MAXNODES 5000LL

maximum number of nodes to regard in the subproblem

Definition at line 70 of file heur_ofins.c.

◆ DEFAULT_MAXCHGRATE

#define DEFAULT_MAXCHGRATE 0.50

maximum percentage of changed objective coefficients

Definition at line 71 of file heur_ofins.c.

◆ DEFAULT_COPYCUTS

#define DEFAULT_COPYCUTS TRUE

if DEFAULT_USELPROWS is FALSE, then should all active cuts from the cutpool of the original scip be copied to constraints of the subscip

Definition at line 73 of file heur_ofins.c.

◆ DEFAULT_MAXCHANGE

#define DEFAULT_MAXCHANGE 0.04

maximal rate of change per coefficient to get fixed

Definition at line 74 of file heur_ofins.c.

◆ DEFAULT_MINIMPROVE

#define DEFAULT_MINIMPROVE 0.01

factor by which OFINS should at least improve the incumbent

Definition at line 75 of file heur_ofins.c.

◆ DEFAULT_ADDALLSOLS

#define DEFAULT_ADDALLSOLS FALSE

should all subproblem solutions be added to the original SCIP?

Definition at line 76 of file heur_ofins.c.

◆ DEFAULT_MINNODES

#define DEFAULT_MINNODES 50LL

minimum number of nodes to regard in the subproblem

Definition at line 77 of file heur_ofins.c.

◆ DEFAULT_NODESOFS

#define DEFAULT_NODESOFS 500LL

number of nodes added to the contingent of the total nodes

Definition at line 78 of file heur_ofins.c.

◆ DEFAULT_NODESQUOT

#define DEFAULT_NODESQUOT 0.1

subproblem nodes in relation to nodes of the original problem

Definition at line 79 of file heur_ofins.c.

◆ DEFAULT_LPLIMFAC

#define DEFAULT_LPLIMFAC 2.0

factor by which the limit on the number of LP depends on the node limit

Definition at line 80 of file heur_ofins.c.

◆ EVENTHDLR_NAME

#define EVENTHDLR_NAME "Ofins"

Definition at line 83 of file heur_ofins.c.

◆ EVENTHDLR_DESC

#define EVENTHDLR_DESC "LP event handler for " HEUR_NAME " heuristic"

Definition at line 84 of file heur_ofins.c.

Function Documentation

◆ SCIP_DECL_EVENTEXEC()

static SCIP_DECL_EVENTEXEC ( eventExecOfins )

static

Definition at line 110 of file heur_ofins.c.

References EVENTHDLR_NAME, NULL, SCIP_CALL, SCIP_EVENTTYPE_LPSOLVED, SCIP_LONGINT_FORMAT, SCIP_OKAY, SCIPdebugMsg, SCIPeventGetType(), SCIPeventhdlrGetName(), SCIPgetNLPs(), and SCIPinterruptSolve().

◆ setupAndSolve()

static SCIP_RETCODE setupAndSolve	(	SCIP *	scip,
		SCIP *	subscip,
		SCIP_HEUR *	heur,
		SCIP_HEURDATA *	heurdata,
		SCIP_RESULT *	result,
		SCIP_Longint	nstallnodes,
		SCIP_Bool *	chgcoeffs
	)

static

Parameters

scip	original SCIP data structure
subscip	sub-SCIP data structure
heur	heuristic data structure
heurdata	euristic's private data structure
result	result data structure
nstallnodes	number of stalling nodes for the subproblem
chgcoeffs	array of changed coefficients

Definition at line 135 of file heur_ofins.c.

References EVENTHDLR_DESC, EVENTHDLR_NAME, FALSE, HEUR_NAME, NULL, SCIP_Bool, SCIP_CALL, SCIP_CALL_ABORT, SCIP_EVENTTYPE_LPSOLVED, SCIP_FOUNDSOL, SCIP_LONGINT_FORMAT, SCIP_OKAY, SCIP_PARAMSETTING_FAST, SCIP_PARAMSETTING_OFF, SCIP_PLUGINNOTFOUND, SCIP_Real, SCIP_STATUS_INFEASIBLE, SCIP_STATUS_INFORUNBD, SCIP_STATUS_UNBOUNDED, SCIP_UNBOUNDED, SCIPABORT, SCIPallocBufferArray, SCIPblkmem(), SCIPcatchEvent(), SCIPcopyLargeNeighborhoodSearch(), SCIPcopyLimits(), SCIPcreateSol(), SCIPdebug, SCIPdebugMsg, SCIPdropEvent(), SCIPerrorMessage, SCIPfindBranchrule(), SCIPfindNodesel(), SCIPfreeBufferArray, SCIPfreeBufferArrayNull, SCIPfreeSol(), SCIPgetBestSol(), SCIPgetNBinVars(), SCIPgetNConss(), SCIPgetNImplVars(), SCIPgetNIntVars(), SCIPgetNNodes(), SCIPgetNSols(), SCIPgetNVars(), SCIPgetPrimalbound(), SCIPgetPrimalRayVal(), SCIPgetReoptLastOptSol(), SCIPgetSols(), SCIPgetSolVal(), SCIPgetSolvingTime(), SCIPgetStatus(), SCIPgetUpperbound(), SCIPgetVars(), SCIPhashmapCreate(), SCIPhashmapFree(), SCIPhashmapGetImage(), SCIPhasPrimalRay(), SCIPincludeEventhdlrBasic(), SCIPinfinity(), SCIPisParamFixed(), SCIPpresolve(), SCIPprintRay(), SCIPprintStatistics(), SCIPsetBoolParam(), SCIPsetIntParam(), SCIPsetLongintParam(), SCIPsetObjlimit(), SCIPsetPresolving(), SCIPsetSeparating(), SCIPsetSolVal(), SCIPsetSubscipsOff(), SCIPsolGetNodenum(), SCIPsolve(), SCIPstatisticPrintf, SCIPtransformProb(), SCIPtranslateSubSol(), SCIPtrySolFree(), SCIPupdatePrimalRay(), SCIPwarningMessage(), and TRUE.

Referenced by applyOfins().

◆ applyOfins()

static SCIP_RETCODE applyOfins	(	SCIP *	scip,
		SCIP_HEUR *	heur,
		SCIP_HEURDATA *	heurdata,
		SCIP_RESULT *	result,
		SCIP_Longint	nstallnodes,
		SCIP_Bool *	chgcoeffs
	)

static

main procedure of the OFINS heuristic, creates and solves a sub-SCIP

Parameters

scip	original SCIP data structure
heur	heuristic data structure
heurdata	euristic's private data structure
result	result data structure
nstallnodes	number of stalling nodes for the subproblem
chgcoeffs	array of changed coefficients

Definition at line 389 of file heur_ofins.c.

References NULL, SCIP_Bool, SCIP_CALL, SCIP_DIDNOTFIND, SCIP_DIDNOTRUN, SCIP_OKAY, SCIPcheckCopyLimits(), SCIPcreate(), SCIPfree(), SCIPgetReoptLastOptSol(), and setupAndSolve().

Referenced by SCIP_DECL_HEUREXEC().

◆ SCIP_DECL_HEURCOPY()

static SCIP_DECL_HEURCOPY ( heurCopyOfins )

static

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

Definition at line 443 of file heur_ofins.c.

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

◆ SCIP_DECL_HEURFREE()

static SCIP_DECL_HEURFREE ( heurFreeOfins )

static

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

Definition at line 457 of file heur_ofins.c.

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

◆ SCIP_DECL_HEUREXEC()

static SCIP_DECL_HEUREXEC ( heurExecOfins )

static

execution method of primal heuristic

Definition at line 477 of file heur_ofins.c.

References applyOfins(), FALSE, MAX, MIN, NULL, REALABS, SCIP_Bool, SCIP_CALL, SCIP_DELAYED, SCIP_DIDNOTRUN, SCIP_Longint, SCIP_LONGINT_FORMAT, SCIP_OKAY, SCIP_Real, SCIP_VARSTATUS_ORIGINAL, SCIPallocBufferArray, SCIPdebugMsg, SCIPfreeBufferArray, SCIPgetNBinVars(), SCIPgetNImplVars(), SCIPgetNIntVars(), SCIPgetNNodes(), SCIPgetNReoptRuns(), SCIPgetReoptOldObjCoef(), SCIPgetVars(), SCIPheurGetData(), SCIPheurGetNBestSolsFound(), SCIPheurGetNCalls(), SCIPisNegative(), SCIPisPositive(), SCIPisReoptEnabled(), SCIPisStopped(), SCIPisZero(), SCIPvarGetStatus(), SCIPvarIsActive(), and TRUE.

SCIP

Detailed Description

Macros

Functions

Macro Definition Documentation

◆ HEUR_NAME

◆ HEUR_DESC

◆ HEUR_DISPCHAR

◆ HEUR_PRIORITY

◆ HEUR_FREQ

◆ HEUR_FREQOFS

◆ HEUR_MAXDEPTH

◆ HEUR_TIMING

◆ HEUR_USESSUBSCIP

◆ DEFAULT_MAXNODES

◆ DEFAULT_MAXCHGRATE

◆ DEFAULT_COPYCUTS

◆ DEFAULT_MAXCHANGE

◆ DEFAULT_MINIMPROVE

◆ DEFAULT_ADDALLSOLS

◆ DEFAULT_MINNODES

◆ DEFAULT_NODESOFS

◆ DEFAULT_NODESQUOT

◆ DEFAULT_LPLIMFAC

◆ EVENTHDLR_NAME

◆ EVENTHDLR_DESC

Function Documentation

◆ SCIP_DECL_EVENTEXEC()

◆ setupAndSolve()

◆ applyOfins()

◆ SCIP_DECL_HEURCOPY()

◆ SCIP_DECL_HEURFREE()

◆ SCIP_DECL_HEUREXEC()