Detailed Description

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

Author: Jakob Witzig

Definition in file heur_ofins.c.

#include <assert.h>
#include <string.h>
#include <stdio.h>
#include "scip/heur_ofins.h"
#include "scip/scipdefplugins.h"
#include "scip/pub_misc.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 'A'

#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	createNewSol (SCIP scip, SCIP subscip, SCIP_VAR *subvars, SCIP_HEUR heur, SCIP_SOL subsol, SCIP_Bool success)

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 31 of file heur_ofins.c.

Referenced by SCIP_DECL_HEURCOPY(), SCIPincludeHeurOfins(), and setupAndSolve().

◆ HEUR_DESC

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

Definition at line 32 of file heur_ofins.c.

Referenced by SCIPincludeHeurOfins().

◆ HEUR_DISPCHAR

#define HEUR_DISPCHAR 'A'

Definition at line 33 of file heur_ofins.c.

Referenced by SCIPincludeHeurOfins().

◆ HEUR_PRIORITY

#define HEUR_PRIORITY 60000

Definition at line 34 of file heur_ofins.c.

Referenced by SCIPincludeHeurOfins().

◆ HEUR_FREQ

#define HEUR_FREQ 0

Definition at line 35 of file heur_ofins.c.

Referenced by SCIPincludeHeurOfins().

◆ HEUR_FREQOFS

#define HEUR_FREQOFS 0

Definition at line 36 of file heur_ofins.c.

Referenced by SCIPincludeHeurOfins().

◆ HEUR_MAXDEPTH

#define HEUR_MAXDEPTH 0

Definition at line 37 of file heur_ofins.c.

Referenced by SCIPincludeHeurOfins().

◆ HEUR_TIMING

#define HEUR_TIMING SCIP_HEURTIMING_BEFORENODE

Definition at line 38 of file heur_ofins.c.

Referenced by SCIPincludeHeurOfins().

◆ HEUR_USESSUBSCIP

#define HEUR_USESSUBSCIP TRUE

does the heuristic use a secondary SCIP instance?

Definition at line 39 of file heur_ofins.c.

Referenced by SCIPincludeHeurOfins().

◆ DEFAULT_MAXNODES

#define DEFAULT_MAXNODES 5000LL

maximum number of nodes to regard in the subproblem

Definition at line 42 of file heur_ofins.c.

Referenced by SCIPincludeHeurOfins().

◆ DEFAULT_MAXCHGRATE

#define DEFAULT_MAXCHGRATE 0.50

maximum percentage of changed objective coefficients

Definition at line 43 of file heur_ofins.c.

Referenced by SCIPincludeHeurOfins().

◆ 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 44 of file heur_ofins.c.

Referenced by SCIPincludeHeurOfins().

◆ DEFAULT_MAXCHANGE

#define DEFAULT_MAXCHANGE 0.04

maximal rate of change per coefficient to get fixed

Definition at line 47 of file heur_ofins.c.

Referenced by SCIPincludeHeurOfins().

◆ DEFAULT_MINIMPROVE

#define DEFAULT_MINIMPROVE 0.01

factor by which OFINS should at least improve the incumbent

Definition at line 48 of file heur_ofins.c.

Referenced by SCIPincludeHeurOfins().

◆ DEFAULT_ADDALLSOLS

#define DEFAULT_ADDALLSOLS FALSE

should all subproblem solutions be added to the original SCIP?

Definition at line 49 of file heur_ofins.c.

Referenced by SCIPincludeHeurOfins().

◆ DEFAULT_MINNODES

#define DEFAULT_MINNODES 50LL

minimum number of nodes to regard in the subproblem

Definition at line 50 of file heur_ofins.c.

Referenced by SCIPincludeHeurOfins().

◆ DEFAULT_NODESOFS

#define DEFAULT_NODESOFS 500LL

number of nodes added to the contingent of the total nodes

Definition at line 51 of file heur_ofins.c.

Referenced by SCIPincludeHeurOfins().

◆ DEFAULT_NODESQUOT

#define DEFAULT_NODESQUOT 0.1

subproblem nodes in relation to nodes of the original problem

Definition at line 52 of file heur_ofins.c.

Referenced by SCIPincludeHeurOfins().

◆ 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 53 of file heur_ofins.c.

Referenced by SCIPincludeHeurOfins().

◆ EVENTHDLR_NAME

#define EVENTHDLR_NAME "Ofins"

Definition at line 56 of file heur_ofins.c.

Referenced by SCIP_DECL_EVENTEXEC(), and setupAndSolve().

◆ EVENTHDLR_DESC

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

Definition at line 57 of file heur_ofins.c.

Referenced by setupAndSolve().

Function Documentation

◆ SCIP_DECL_EVENTEXEC()

static SCIP_DECL_EVENTEXEC ( eventExecOfins )

static

Definition at line 83 of file heur_ofins.c.

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

◆ createNewSol()

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

static

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

Parameters

scip	original SCIP data structure
subscip	SCIP structure of the subproblem
subvars	the variables of the subproblem
heur	RENS heuristic structure
subsol	solution of the subproblem
success	used to store whether new solution was found or not

Definition at line 108 of file heur_ofins.c.

References SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPcreateSol(), SCIPfreeBufferArray, SCIPgetNOrigVars(), SCIPgetSolVals(), SCIPgetVarsData(), SCIPsetSolVals(), SCIPtrySolFree(), setupAndSolve(), and TRUE.

Referenced by SCIP_DECL_EVENTEXEC(), and setupAndSolve().

◆ 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 154 of file heur_ofins.c.

References applyOfins(), createNewSol(), EVENTHDLR_DESC, EVENTHDLR_NAME, FALSE, HEUR_NAME, SCIP_Bool, SCIP_CALL, SCIP_CALL_ABORT, SCIP_EVENTTYPE_LPSOLVED, SCIP_FOUNDSOL, 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(), SCIPgetNOrigVars(), 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(), SCIPupdatePrimalRay(), SCIPvarGetProbindex(), SCIPwarningMessage(), and TRUE.

Referenced by applyOfins(), and createNewSol().

◆ 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 409 of file heur_ofins.c.

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

Referenced by SCIP_DECL_HEUREXEC(), and setupAndSolve().

◆ SCIP_DECL_HEURCOPY()

static SCIP_DECL_HEURCOPY ( heurCopyOfins )

static

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

Definition at line 463 of file heur_ofins.c.

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

Referenced by applyOfins().

◆ 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 477 of file heur_ofins.c.

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

Referenced by SCIP_DECL_HEURCOPY().

◆ SCIP_DECL_HEUREXEC()

static SCIP_DECL_HEUREXEC ( heurExecOfins )

static

execution method of primal heuristic

Definition at line 497 of file heur_ofins.c.

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

Referenced by SCIP_DECL_HEURFREE().

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()

◆ createNewSol()

◆ setupAndSolve()

◆ applyOfins()

◆ SCIP_DECL_HEURCOPY()

◆ SCIP_DECL_HEURFREE()

◆ SCIP_DECL_HEUREXEC()