Detailed Description

Adaptive large neighborhood search heuristic that orchestrates popular LNS heuristics.

Author: Gregor Hendel

Definition in file heur_alns.c.

#include "blockmemshell/memory.h"
#include "scip/cons_linear.h"
#include "scip/heur_alns.h"
#include "scip/heuristics.h"
#include "scip/pub_bandit_epsgreedy.h"
#include "scip/pub_bandit_exp3.h"
#include "scip/pub_bandit.h"
#include "scip/pub_bandit_ucb.h"
#include "scip/pub_event.h"
#include "scip/pub_heur.h"
#include "scip/pub_message.h"
#include "scip/pub_misc.h"
#include "scip/pub_misc_select.h"
#include "scip/pub_sol.h"
#include "scip/pub_var.h"
#include "scip/scip_bandit.h"
#include "scip/scip_branch.h"
#include "scip/scip_cons.h"
#include "scip/scip_event.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_nodesel.h"
#include "scip/scip_numerics.h"
#include "scip/scip_param.h"
#include "scip/scip_prob.h"
#include "scip/scip_randnumgen.h"
#include "scip/scip_sol.h"
#include "scip/scip_solve.h"
#include "scip/scip_solvingstats.h"
#include "scip/scip_table.h"
#include "scip/scip_timing.h"
#include "scip/scip_tree.h"
#include "scip/scip_var.h"
#include <string.h>
#include <strings.h>

Go to the source code of this file.

Data Structures
struct	NH_Stats

struct	NH_FixingRate

struct	Nh

struct	data_mutation

struct	data_crossover

struct	data_dins

struct	SolveLimits

struct	VarPrio

Macros
#define	HEUR_NAME "alns"

#define	HEUR_DESC "Large neighborhood search heuristic that orchestrates the popular neighborhoods Local Branching, RINS, RENS, DINS etc."

#define	HEUR_DISPCHAR 'L'

#define	HEUR_PRIORITY -1100500

#define	HEUR_FREQ 20

#define	HEUR_FREQOFS 0

#define	HEUR_MAXDEPTH -1

#define	HEUR_TIMING SCIP_HEURTIMING_AFTERNODE

#define	HEUR_USESSUBSCIP TRUE

#define	NNEIGHBORHOODS 8

#define	DEFAULT_NODESQUOT 0.1

#define	DEFAULT_NODESOFFSET 500LL

#define	DEFAULT_NSOLSLIM 3

#define	DEFAULT_MINNODES 50LL

#define	DEFAULT_MAXNODES 5000LL

#define	DEFAULT_WAITINGNODES 25LL

#define	DEFAULT_TARGETNODEFACTOR 1.05

#define	LRATEMIN 0.01

#define	LPLIMFAC 4.0

#define	DEFAULT_MINIMPROVELOW 0.01

#define	DEFAULT_MINIMPROVEHIGH 0.01

#define	MINIMPROVEFAC 1.5

#define	DEFAULT_STARTMINIMPROVE 0.01

#define	DEFAULT_ADJUSTMINIMPROVE FALSE

#define	DEFAULT_ADJUSTTARGETNODES TRUE

#define	DEFAULT_BESTSOLWEIGHT 1

#define	DEFAULT_BANDITALGO 'u'

#define	DEFAULT_REWARDCONTROL 0.8

#define	DEFAULT_SCALEBYEFFORT TRUE

#define	DEFAULT_RESETWEIGHTS TRUE

#define	DEFAULT_SUBSCIPRANDSEEDS FALSE

#define	DEFAULT_REWARDBASELINE 0.5

#define	DEFAULT_FIXTOL 0.1

#define	DEFAULT_UNFIXTOL 0.1

#define	DEFAULT_USELOCALREDCOST FALSE

#define	DEFAULT_BETA 0.0

#define	DEFAULT_EPS 0.4685844

#define	DEFAULT_ALPHA 0.0016

#define	DEFAULT_GAMMA 0.07041455

#define	DEFAULT_USEREDCOST TRUE

#define	DEFAULT_USEPSCOST TRUE

#define	DEFAULT_USEDISTANCES TRUE

#define	DEFAULT_DOMOREFIXINGS TRUE

#define	DEFAULT_ADJUSTFIXINGRATE TRUE

#define	FIXINGRATE_DECAY 0.75

#define	FIXINGRATE_STARTINC 0.2

#define	DEFAULT_USESUBSCIPHEURS FALSE

#define	DEFAULT_COPYCUTS FALSE

#define	DEFAULT_REWARDFILENAME "-"

#define	DEFAULT_SEED 113

#define	MUTATIONSEED 121

#define	CROSSOVERSEED 321

#define	DEFAULT_MINFIXINGRATE_RENS 0.3

#define	DEFAULT_MAXFIXINGRATE_RENS 0.9

#define	DEFAULT_ACTIVE_RENS TRUE

#define	DEFAULT_PRIORITY_RENS 1.0

#define	DEFAULT_MINFIXINGRATE_RINS 0.3

#define	DEFAULT_MAXFIXINGRATE_RINS 0.9

#define	DEFAULT_ACTIVE_RINS TRUE

#define	DEFAULT_PRIORITY_RINS 1.0

#define	DEFAULT_MINFIXINGRATE_MUTATION 0.3

#define	DEFAULT_MAXFIXINGRATE_MUTATION 0.9

#define	DEFAULT_ACTIVE_MUTATION TRUE

#define	DEFAULT_PRIORITY_MUTATION 1.0

#define	DEFAULT_MINFIXINGRATE_LOCALBRANCHING 0.3

#define	DEFAULT_MAXFIXINGRATE_LOCALBRANCHING 0.9

#define	DEFAULT_ACTIVE_LOCALBRANCHING TRUE

#define	DEFAULT_PRIORITY_LOCALBRANCHING 1.0

#define	DEFAULT_MINFIXINGRATE_PROXIMITY 0.3

#define	DEFAULT_MAXFIXINGRATE_PROXIMITY 0.9

#define	DEFAULT_ACTIVE_PROXIMITY TRUE

#define	DEFAULT_PRIORITY_PROXIMITY 1.0

#define	DEFAULT_MINFIXINGRATE_CROSSOVER 0.3

#define	DEFAULT_MAXFIXINGRATE_CROSSOVER 0.9

#define	DEFAULT_ACTIVE_CROSSOVER TRUE

#define	DEFAULT_PRIORITY_CROSSOVER 1.0

#define	DEFAULT_MINFIXINGRATE_ZEROOBJECTIVE 0.3

#define	DEFAULT_MAXFIXINGRATE_ZEROOBJECTIVE 0.9

#define	DEFAULT_ACTIVE_ZEROOBJECTIVE TRUE

#define	DEFAULT_PRIORITY_ZEROOBJECTIVE 1.0

#define	DEFAULT_MINFIXINGRATE_DINS 0.3

#define	DEFAULT_MAXFIXINGRATE_DINS 0.9

#define	DEFAULT_ACTIVE_DINS TRUE

#define	DEFAULT_PRIORITY_DINS 1.0

#define	DEFAULT_NSOLS_CROSSOVER 2

#define	DEFAULT_NPOOLSOLS_DINS 5

#define	EVENTHDLR_NAME "Alns"

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

#define	SCIP_EVENTTYPE_ALNS (SCIP_EVENTTYPE_LPSOLVED \| SCIP_EVENTTYPE_SOLFOUND \| SCIP_EVENTTYPE_BESTSOLFOUND)

#define	TABLE_NAME_NEIGHBORHOOD "neighborhood"

#define	TABLE_DESC_NEIGHBORHOOD "ALNS neighborhood statistics"

#define	TABLE_POSITION_NEIGHBORHOOD 12500

#define	TABLE_EARLIEST_STAGE_NEIGHBORHOOD SCIP_STAGE_TRANSFORMED

#define	DECL_VARFIXINGS(x)

#define	DECL_CHANGESUBSCIP(x)

#define	DECL_NHINIT(x)

#define	DECL_NHEXIT(x)

#define	DECL_NHFREE(x)

#define	DECL_NHREFSOL(x)

#define	DECL_NHDEACTIVATE(x)

#define	NHISTENTRIES 7

Typedefs
typedef struct data_crossover	DATA_CROSSOVER

typedef struct data_mutation	DATA_MUTATION

typedef struct data_dins	DATA_DINS

typedef struct NH_FixingRate	NH_FIXINGRATE

typedef struct NH_Stats	NH_STATS

typedef struct Nh	NH

typedef struct VarPrio	VARPRIO

typedef enum HistIndex	HISTINDEX

typedef struct SolveLimits	SOLVELIMITS

Enumerations
enum	HistIndex { HIDX_OPT = 0, HIDX_USR = 1, HIDX_NODELIM = 2, HIDX_STALLNODE = 3, HIDX_INFEAS = 4, HIDX_SOLLIM = 5, HIDX_OTHER = 6 }

Functions
static SCIP_RETCODE	resetFixingRate (SCIP scip, NH_FIXINGRATE fixingrate)

static void	resetCurrentNeighborhood (SCIP_HEURDATA *heurdata)

static void	updateFixingRateIncrement (NH_FIXINGRATE *fx)

static void	increaseFixingRate (NH_FIXINGRATE *fx)

static void	decreaseFixingRate (NH_FIXINGRATE *fx)

static void	updateFixingRate (SCIP scip, NH neighborhood, SCIP_STATUS subscipstatus, NH_STATS *runstats)

static void	increaseTargetNodeLimit (SCIP_HEURDATA *heurdata)

static void	resetTargetNodeLimit (SCIP_HEURDATA *heurdata)

static void	updateTargetNodeLimit (SCIP_HEURDATA heurdata, NH_STATS runstats, SCIP_STATUS subscipstatus)

static void	resetMinimumImprovement (SCIP_HEURDATA *heurdata)

static void	increaseMinimumImprovement (SCIP_HEURDATA *heurdata)

static void	decreaseMinimumImprovement (SCIP_HEURDATA *heurdata)

static void	updateMinimumImprovement (SCIP_HEURDATA heurdata, SCIP_STATUS subscipstatus, NH_STATS runstats)

static SCIP_RETCODE	neighborhoodStatsReset (SCIP scip, NH_STATS stats)

static SCIP_RETCODE	alnsIncludeNeighborhood (SCIP scip, SCIP_HEURDATA heurdata, NH *neighborhood, const char name, SCIP_Real minfixingrate, SCIP_Real maxfixingrate, SCIP_Bool active, SCIP_Real priority, DECL_VARFIXINGS((varfixings)), DECL_CHANGESUBSCIP((changesubscip)), DECL_NHINIT((nhinit)), DECL_NHEXIT((nhexit)), DECL_NHFREE((nhfree)), DECL_NHREFSOL((nhrefsol)), DECL_NHDEACTIVATE((*nhdeactivate)))

static SCIP_RETCODE	alnsFreeNeighborhood (SCIP scip, NH *neighborhood)

static SCIP_RETCODE	neighborhoodInit (SCIP scip, NH neighborhood)

static SCIP_RETCODE	neighborhoodExit (SCIP scip, NH neighborhood)

static SCIP_RETCODE	transferSolution (SCIP subscip, SCIP_EVENTDATA eventdata)

static	SCIP_DECL_EVENTEXEC (eventExecAlns)

static void	initRunStats (SCIP scip, NH_STATS stats)

static void	updateRunStats (SCIP scip, NH_STATS stats, SCIP *subscip)

static int	getHistIndex (SCIP_STATUS subscipstatus)

static void	printNeighborhoodStatistics (SCIP scip, SCIP_HEURDATA heurdata, FILE *file)

static void	updateNeighborhoodStats (SCIP scip, NH_STATS runstats, NH *neighborhood, SCIP_STATUS subscipstatus)

static	SCIP_DECL_SORTINDCOMP (sortIndCompAlns)

static SCIP_Real	getVariableRedcostScore (SCIP scip, SCIP_VAR var, SCIP_Real refsolval, SCIP_Bool uselocalredcost)

static SCIP_Real	getVariablePscostScore (SCIP scip, SCIP_VAR var, SCIP_Real refsolval)

static void	tryAdd2variableBuffer (SCIP scip, SCIP_VAR var, SCIP_Real val, SCIP_VAR *varbuf, SCIP_Real valbuf, int *nfixings, SCIP_Bool integer)

static SCIP_RETCODE	neighborhoodGetRefsol (SCIP scip, NH neighborhood, SCIP_SOL **solptr)

static SCIP_RETCODE	alnsFixMoreVariables (SCIP scip, SCIP_HEURDATA heurdata, SCIP_SOL refsol, SCIP_VAR varbuf, SCIP_Real valbuf, int nfixings, int ntargetfixings, SCIP_Bool success)

static SCIP_RETCODE	createBandit (SCIP scip, SCIP_HEURDATA heurdata, SCIP_Real *priorities, unsigned int initseed)

static	SCIP_DECL_HEURCOPY (heurCopyAlns)

static SCIP_RETCODE	alnsUnfixVariables (SCIP scip, SCIP_HEURDATA heurdata, SCIP_VAR *varbuf, SCIP_Real valbuf, int nfixings, int ntargetfixings, SCIP_Bool success)

static SCIP_RETCODE	neighborhoodFixVariables (SCIP scip, SCIP_HEURDATA heurdata, NH neighborhood, SCIP_VAR varbuf, SCIP_Real valbuf, int nfixings, SCIP_RESULT result)

static SCIP_RETCODE	neighborhoodChangeSubscip (SCIP sourcescip, SCIP targetscip, NH neighborhood, SCIP_VAR targetvars, int ndomchgs, int nchgobjs, int naddedconss, SCIP_Bool *success)

static SCIP_RETCODE	setLimits (SCIP subscip, SOLVELIMITS solvelimits)

static SCIP_RETCODE	determineLimits (SCIP scip, SCIP_HEUR heur, SOLVELIMITS solvelimits, SCIP_Bool runagain)

static SCIP_BANDIT *	getBandit (SCIP_HEURDATA *heurdata)

static SCIP_RETCODE	selectNeighborhood (SCIP scip, SCIP_HEURDATA heurdata, int *neighborhoodidx)

static SCIP_RETCODE	getReward (SCIP scip, SCIP_HEURDATA heurdata, NH_STATS runstats, SCIP_Real rewardptr)

static SCIP_RETCODE	updateBanditAlgorithm (SCIP scip, SCIP_HEURDATA heurdata, SCIP_Real reward, int neighborhoodidx)

static SCIP_RETCODE	setupSubScip (SCIP scip, SCIP subscip, SCIP_VAR *subvars, SOLVELIMITS solvelimits, SCIP_HEUR *heur, SCIP_Bool objchgd)

static	SCIP_DECL_HEUREXEC (heurExecAlns)

static	DECL_VARFIXINGS (varFixingsRens)

static	DECL_CHANGESUBSCIP (changeSubscipRens)

static SCIP_RETCODE	fixMatchingSolutionValues (SCIP scip, SCIP_SOL sols, int nsols, SCIP_VAR vars, int nvars, SCIP_VAR varbuf, SCIP_Real valbuf, int *nfixings)

static	DECL_VARFIXINGS (varFixingsRins)

static	DECL_NHINIT (nhInitCrossover)

static	DECL_NHEXIT (nhExitCrossover)

static	DECL_NHFREE (nhFreeCrossover)

static	DECL_VARFIXINGS (varFixingsCrossover)

static	DECL_NHREFSOL (nhRefsolCrossover)

static	DECL_NHINIT (nhInitMutation)

static	DECL_NHEXIT (nhExitMutation)

static	DECL_VARFIXINGS (varFixingsMutation)

static SCIP_RETCODE	addLocalBranchingConstraint (SCIP sourcescip, SCIP targetscip, SCIP_VAR *subvars, int distance, SCIP_Bool success, int *naddedconss)

static	DECL_CHANGESUBSCIP (changeSubscipLocalbranching)

static	DECL_CHANGESUBSCIP (changeSubscipProximity)

static	DECL_CHANGESUBSCIP (changeSubscipZeroobjective)

static void	computeIntegerVariableBoundsDins (SCIP scip, SCIP_VAR var, SCIP_Real lbptr, SCIP_Real ubptr)

static	DECL_VARFIXINGS (varFixingsDins)

static	DECL_CHANGESUBSCIP (changeSubscipDins)

static	DECL_NHFREE (nhFreeDins)

static	DECL_NHREFSOL (nhRefsolIncumbent)

static	DECL_NHDEACTIVATE (nhDeactivateDiscreteVars)

static	DECL_NHDEACTIVATE (nhDeactivateBinVars)

static	DECL_NHDEACTIVATE (nhDeactivateObjVars)

static SCIP_RETCODE	includeNeighborhoods (SCIP scip, SCIP_HEURDATA heurdata)

static	SCIP_DECL_HEURINIT (heurInitAlns)

static	SCIP_DECL_HEURINITSOL (heurInitsolAlns)

static	SCIP_DECL_HEUREXIT (heurExitAlns)

static	SCIP_DECL_HEURFREE (heurFreeAlns)

static	SCIP_DECL_TABLEOUTPUT (tableOutputNeighborhood)

SCIP_RETCODE	SCIPincludeHeurAlns (SCIP *scip)

Macro Definition Documentation

◆ HEUR_NAME

#define HEUR_NAME "alns"

Definition at line 65 of file heur_alns.c.

Referenced by SCIP_DECL_HEURCOPY(), SCIP_DECL_TABLEOUTPUT(), and SCIPincludeHeurAlns().

◆ HEUR_DESC

#define HEUR_DESC "Large neighborhood search heuristic that orchestrates the popular neighborhoods Local Branching, RINS, RENS, DINS etc."

Definition at line 66 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ HEUR_DISPCHAR

#define HEUR_DISPCHAR 'L'

Definition at line 67 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ HEUR_PRIORITY

#define HEUR_PRIORITY -1100500

Definition at line 68 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ HEUR_FREQ

#define HEUR_FREQ 20

Definition at line 69 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ HEUR_FREQOFS

#define HEUR_FREQOFS 0

Definition at line 70 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ HEUR_MAXDEPTH

#define HEUR_MAXDEPTH -1

Definition at line 71 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ HEUR_TIMING

#define HEUR_TIMING SCIP_HEURTIMING_AFTERNODE

Definition at line 72 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ HEUR_USESSUBSCIP

#define HEUR_USESSUBSCIP TRUE

does the heuristic use a secondary SCIP instance?

Definition at line 73 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ NNEIGHBORHOODS

#define NNEIGHBORHOODS 8

Definition at line 75 of file heur_alns.c.

Referenced by SCIP_DECL_HEUREXEC(), SCIP_DECL_HEURFREE(), and SCIPincludeHeurAlns().

◆ DEFAULT_NODESQUOT

#define DEFAULT_NODESQUOT 0.1

Definition at line 80 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_NODESOFFSET

#define DEFAULT_NODESOFFSET 500LL

Definition at line 81 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_NSOLSLIM

#define DEFAULT_NSOLSLIM 3

Definition at line 82 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_MINNODES

#define DEFAULT_MINNODES 50LL

Definition at line 83 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_MAXNODES

#define DEFAULT_MAXNODES 5000LL

Definition at line 84 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_WAITINGNODES

#define DEFAULT_WAITINGNODES 25LL

number of nodes since last incumbent solution that the heuristic should wait

Definition at line 85 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_TARGETNODEFACTOR

#define DEFAULT_TARGETNODEFACTOR 1.05

Definition at line 86 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ LRATEMIN

#define LRATEMIN 0.01

lower bound for learning rate for target nodes and minimum improvement

Definition at line 87 of file heur_alns.c.

Referenced by updateFixingRateIncrement().

◆ LPLIMFAC

#define LPLIMFAC 4.0

Definition at line 88 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_MINIMPROVELOW

#define DEFAULT_MINIMPROVELOW 0.01

Definition at line 93 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_MINIMPROVEHIGH

#define DEFAULT_MINIMPROVEHIGH 0.01

Definition at line 94 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ MINIMPROVEFAC

#define MINIMPROVEFAC 1.5

Definition at line 95 of file heur_alns.c.

Referenced by decreaseMinimumImprovement(), and increaseMinimumImprovement().

◆ DEFAULT_STARTMINIMPROVE

#define DEFAULT_STARTMINIMPROVE 0.01

Definition at line 96 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_ADJUSTMINIMPROVE

#define DEFAULT_ADJUSTMINIMPROVE FALSE

Definition at line 97 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_ADJUSTTARGETNODES

#define DEFAULT_ADJUSTTARGETNODES TRUE

should the target nodes be dynamically adjusted?

Definition at line 98 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_BESTSOLWEIGHT

#define DEFAULT_BESTSOLWEIGHT 1

Definition at line 103 of file heur_alns.c.

Referenced by updateNeighborhoodStats().

◆ DEFAULT_BANDITALGO

#define DEFAULT_BANDITALGO 'u'

the default bandit algorithm: (u)pper confidence bounds, (e)xp.3, epsilon (g)reedy

Definition at line 104 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_REWARDCONTROL

#define DEFAULT_REWARDCONTROL 0.8

reward control to increase the weight of the simple solution indicator and decrease the weight of the closed gap reward

Definition at line 105 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_SCALEBYEFFORT

#define DEFAULT_SCALEBYEFFORT TRUE

should the reward be scaled by the effort?

Definition at line 106 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_RESETWEIGHTS

#define DEFAULT_RESETWEIGHTS TRUE

should the bandit algorithms be reset when a new problem is read?

Definition at line 107 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_SUBSCIPRANDSEEDS

#define DEFAULT_SUBSCIPRANDSEEDS FALSE

should random seeds of sub-SCIPs be altered to increase diversification?

Definition at line 108 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_REWARDBASELINE

#define DEFAULT_REWARDBASELINE 0.5

the reward baseline to separate successful and failed calls

Definition at line 109 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_FIXTOL

#define DEFAULT_FIXTOL 0.1

tolerance by which the fixing rate may be missed without generic fixing

Definition at line 110 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_UNFIXTOL

#define DEFAULT_UNFIXTOL 0.1

tolerance by which the fixing rate may be exceeded without generic unfixing

Definition at line 111 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_USELOCALREDCOST

#define DEFAULT_USELOCALREDCOST FALSE

should local reduced costs be used for generic (un)fixing?

Definition at line 112 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_BETA

#define DEFAULT_BETA 0.0

default reward offset between 0 and 1 at every observation for exp3

Definition at line 113 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_EPS

#define DEFAULT_EPS 0.4685844

increase exploration in epsilon-greedy bandit algorithm

Definition at line 119 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_ALPHA

#define DEFAULT_ALPHA 0.0016

parameter to increase the confidence width in UCB

Definition at line 120 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_GAMMA

#define DEFAULT_GAMMA 0.07041455

default weight between uniform (gamma ~ 1) and weight driven (gamma ~ 0) probability distribution for exp3

Definition at line 121 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_USEREDCOST

#define DEFAULT_USEREDCOST TRUE

should reduced cost scores be used for variable priorization?

Definition at line 125 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_USEPSCOST

#define DEFAULT_USEPSCOST TRUE

should pseudo cost scores be used for variable priorization?

Definition at line 126 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_USEDISTANCES

#define DEFAULT_USEDISTANCES TRUE

should distances from fixed variables be used for variable priorization

Definition at line 127 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_DOMOREFIXINGS

#define DEFAULT_DOMOREFIXINGS TRUE

should the ALNS heuristic do more fixings by itself based on variable prioritization until the target fixing rate is reached?

Definition at line 128 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_ADJUSTFIXINGRATE

#define DEFAULT_ADJUSTFIXINGRATE TRUE

should the heuristic adjust the target fixing rate based on the success?

Definition at line 131 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ FIXINGRATE_DECAY

#define FIXINGRATE_DECAY 0.75

geometric decay for fixing rate adjustments

Definition at line 132 of file heur_alns.c.

Referenced by updateFixingRateIncrement().

◆ FIXINGRATE_STARTINC

#define FIXINGRATE_STARTINC 0.2

initial increment value for fixing rate

Definition at line 133 of file heur_alns.c.

Referenced by resetFixingRate().

◆ DEFAULT_USESUBSCIPHEURS

#define DEFAULT_USESUBSCIPHEURS FALSE

should the heuristic activate other sub-SCIP heuristics during its search?

Definition at line 134 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_COPYCUTS

#define DEFAULT_COPYCUTS FALSE

should cutting planes be copied to the sub-SCIP?

Definition at line 135 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DEFAULT_REWARDFILENAME

#define DEFAULT_REWARDFILENAME "-"

file name to store all rewards and the selection of the bandit

Definition at line 136 of file heur_alns.c.

Referenced by SCIP_DECL_HEURINIT(), and SCIPincludeHeurAlns().

◆ DEFAULT_SEED

#define DEFAULT_SEED 113

Definition at line 139 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ MUTATIONSEED

#define MUTATIONSEED 121

Definition at line 140 of file heur_alns.c.

Referenced by DECL_NHINIT().

◆ CROSSOVERSEED

#define CROSSOVERSEED 321

Definition at line 141 of file heur_alns.c.

Referenced by DECL_NHINIT().

◆ DEFAULT_MINFIXINGRATE_RENS

#define DEFAULT_MINFIXINGRATE_RENS 0.3

Definition at line 144 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_MAXFIXINGRATE_RENS

#define DEFAULT_MAXFIXINGRATE_RENS 0.9

Definition at line 145 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_ACTIVE_RENS

#define DEFAULT_ACTIVE_RENS TRUE

Definition at line 146 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_PRIORITY_RENS

#define DEFAULT_PRIORITY_RENS 1.0

Definition at line 147 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_MINFIXINGRATE_RINS

#define DEFAULT_MINFIXINGRATE_RINS 0.3

Definition at line 149 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_MAXFIXINGRATE_RINS

#define DEFAULT_MAXFIXINGRATE_RINS 0.9

Definition at line 150 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_ACTIVE_RINS

#define DEFAULT_ACTIVE_RINS TRUE

Definition at line 151 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_PRIORITY_RINS

#define DEFAULT_PRIORITY_RINS 1.0

Definition at line 152 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_MINFIXINGRATE_MUTATION

#define DEFAULT_MINFIXINGRATE_MUTATION 0.3

Definition at line 154 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_MAXFIXINGRATE_MUTATION

#define DEFAULT_MAXFIXINGRATE_MUTATION 0.9

Definition at line 155 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_ACTIVE_MUTATION

#define DEFAULT_ACTIVE_MUTATION TRUE

Definition at line 156 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_PRIORITY_MUTATION

#define DEFAULT_PRIORITY_MUTATION 1.0

Definition at line 157 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_MINFIXINGRATE_LOCALBRANCHING

#define DEFAULT_MINFIXINGRATE_LOCALBRANCHING 0.3

Definition at line 159 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_MAXFIXINGRATE_LOCALBRANCHING

#define DEFAULT_MAXFIXINGRATE_LOCALBRANCHING 0.9

Definition at line 160 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_ACTIVE_LOCALBRANCHING

#define DEFAULT_ACTIVE_LOCALBRANCHING TRUE

Definition at line 161 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_PRIORITY_LOCALBRANCHING

#define DEFAULT_PRIORITY_LOCALBRANCHING 1.0

Definition at line 162 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_MINFIXINGRATE_PROXIMITY

#define DEFAULT_MINFIXINGRATE_PROXIMITY 0.3

Definition at line 164 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_MAXFIXINGRATE_PROXIMITY

#define DEFAULT_MAXFIXINGRATE_PROXIMITY 0.9

Definition at line 165 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_ACTIVE_PROXIMITY

#define DEFAULT_ACTIVE_PROXIMITY TRUE

Definition at line 166 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_PRIORITY_PROXIMITY

#define DEFAULT_PRIORITY_PROXIMITY 1.0

Definition at line 167 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_MINFIXINGRATE_CROSSOVER

#define DEFAULT_MINFIXINGRATE_CROSSOVER 0.3

Definition at line 169 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_MAXFIXINGRATE_CROSSOVER

#define DEFAULT_MAXFIXINGRATE_CROSSOVER 0.9

Definition at line 170 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_ACTIVE_CROSSOVER

#define DEFAULT_ACTIVE_CROSSOVER TRUE

Definition at line 171 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_PRIORITY_CROSSOVER

#define DEFAULT_PRIORITY_CROSSOVER 1.0

Definition at line 172 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_MINFIXINGRATE_ZEROOBJECTIVE

#define DEFAULT_MINFIXINGRATE_ZEROOBJECTIVE 0.3

Definition at line 174 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_MAXFIXINGRATE_ZEROOBJECTIVE

#define DEFAULT_MAXFIXINGRATE_ZEROOBJECTIVE 0.9

Definition at line 175 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_ACTIVE_ZEROOBJECTIVE

#define DEFAULT_ACTIVE_ZEROOBJECTIVE TRUE

Definition at line 176 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_PRIORITY_ZEROOBJECTIVE

#define DEFAULT_PRIORITY_ZEROOBJECTIVE 1.0

Definition at line 177 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_MINFIXINGRATE_DINS

#define DEFAULT_MINFIXINGRATE_DINS 0.3

Definition at line 179 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_MAXFIXINGRATE_DINS

#define DEFAULT_MAXFIXINGRATE_DINS 0.9

Definition at line 180 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_ACTIVE_DINS

#define DEFAULT_ACTIVE_DINS TRUE

Definition at line 181 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_PRIORITY_DINS

#define DEFAULT_PRIORITY_DINS 1.0

Definition at line 182 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_NSOLS_CROSSOVER

#define DEFAULT_NSOLS_CROSSOVER 2

parameter for the number of solutions that crossover should combine

Definition at line 184 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ DEFAULT_NPOOLSOLS_DINS

#define DEFAULT_NPOOLSOLS_DINS 5

number of pool solutions where binary solution values must agree

Definition at line 185 of file heur_alns.c.

Referenced by includeNeighborhoods().

◆ EVENTHDLR_NAME

#define EVENTHDLR_NAME "Alns"

Definition at line 188 of file heur_alns.c.

Referenced by SCIP_DECL_EVENTEXEC(), and SCIP_DECL_HEUREXEC().

◆ EVENTHDLR_DESC

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

Definition at line 189 of file heur_alns.c.

Referenced by SCIP_DECL_HEUREXEC().

◆ SCIP_EVENTTYPE_ALNS

#define SCIP_EVENTTYPE_ALNS (SCIP_EVENTTYPE_LPSOLVED | SCIP_EVENTTYPE_SOLFOUND | SCIP_EVENTTYPE_BESTSOLFOUND)

Definition at line 190 of file heur_alns.c.

Referenced by SCIP_DECL_EVENTEXEC(), and SCIP_DECL_HEUREXEC().

◆ TABLE_NAME_NEIGHBORHOOD

#define TABLE_NAME_NEIGHBORHOOD "neighborhood"

Definition at line 193 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ TABLE_DESC_NEIGHBORHOOD

#define TABLE_DESC_NEIGHBORHOOD "ALNS neighborhood statistics"

Definition at line 194 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ TABLE_POSITION_NEIGHBORHOOD

#define TABLE_POSITION_NEIGHBORHOOD 12500

the position of the statistics table

Definition at line 195 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ TABLE_EARLIEST_STAGE_NEIGHBORHOOD

#define TABLE_EARLIEST_STAGE_NEIGHBORHOOD SCIP_STAGE_TRANSFORMED

output of the statistics table is only printed from this stage onwards

Definition at line 196 of file heur_alns.c.

Referenced by SCIPincludeHeurAlns().

◆ DECL_VARFIXINGS

#define DECL_VARFIXINGS ( x )

Value:

SCIP_RETCODE x ( \
   SCIP*                 scip,               /**< SCIP data structure */                     \
   NH*                   neighborhood,       /**< ALNS neighborhood data structure */         \
   SCIP_VAR**            varbuf,             /**< buffer array to collect variables to fix */\
   SCIP_Real*            valbuf,             /**< buffer array to collect fixing values */   \
   int*                  nfixings,           /**< pointer to store the number of fixings */  \
   SCIP_RESULT*          result              /**< result pointer */                          \
   )

callback to collect variable fixings of neighborhood

Definition at line 226 of file heur_alns.c.

Referenced by computeIntegerVariableBoundsDins(), DECL_NHEXIT(), DECL_NHFREE(), fixMatchingSolutionValues(), and SCIP_DECL_HEUREXEC().

◆ DECL_CHANGESUBSCIP

#define DECL_CHANGESUBSCIP ( x )

Value:

SCIP_RETCODE x (  \
   SCIP*                 sourcescip,         /**< source SCIP data structure */\
   SCIP*                 targetscip,         /**< target SCIP data structure */\
   SCIP_VAR**            subvars,            /**< array of targetscip variables in the same order as the source SCIP variables */\
   int*                  ndomchgs,           /**< pointer to store the number of performed domain changes */\
   int*                  nchgobjs,           /**< pointer to store the number of changed objective coefficients */ \
   int*                  naddedconss,        /**< pointer to store the number of additional constraints */\
   SCIP_Bool*            success             /**< pointer to store if the sub-MIP was successfully adjusted */\
   )

callback for subproblem changes other than variable fixings

this callback can be used to further modify the subproblem by changes other than variable fixings. Typical modifications include restrictions of variable domains, the formulation of additional constraints, or changed objective coefficients.

The callback should set the success pointer to indicate whether it was successful with its modifications or not.

Definition at line 243 of file heur_alns.c.

Referenced by addLocalBranchingConstraint(), DECL_CHANGESUBSCIP(), and DECL_VARFIXINGS().

◆ DECL_NHINIT

#define DECL_NHINIT ( x )

Value:

SCIP_RETCODE x (                                          \
   SCIP*                 scip,               /**< SCIP data structure */         \
   NH*                   neighborhood        /**< neighborhood data structure */ \
   )

optional initialization callback for neighborhoods when a new problem is read

Definition at line 254 of file heur_alns.c.

Referenced by DECL_NHREFSOL(), and DECL_VARFIXINGS().

◆ DECL_NHEXIT

#define DECL_NHEXIT ( x )

Value:

SCIP_RETCODE x ( \
   SCIP*                 scip,               /**< SCIP data structure */         \
   NH*                   neighborhood        /**< neighborhood data structure */ \
   )

deinitialization callback for neighborhoods when exiting a problem

Definition at line 260 of file heur_alns.c.

Referenced by DECL_NHINIT().

◆ DECL_NHFREE

#define DECL_NHFREE ( x )

Value:

SCIP_RETCODE x (      \
   SCIP*                 scip,               /**< SCIP data structure */         \
   NH*                   neighborhood        /**< neighborhood data structure */ \
   )

deinitialization callback for neighborhoods before SCIP is freed

Definition at line 266 of file heur_alns.c.

Referenced by DECL_CHANGESUBSCIP(), and DECL_NHEXIT().

◆ DECL_NHREFSOL

#define DECL_NHREFSOL ( x )

Value:

SCIP_RETCODE x (                                       \
   SCIP*                 scip,               /**< SCIP data structure */  \
   NH*                   neighborhood,       /**< neighborhood data structure */ \
   SCIP_SOL**            solptr,             /**< pointer to store the reference solution */ \
   SCIP_RESULT*          result              /**< pointer to indicate the callback success whether a reference solution is available */ \
   )

callback function to return a feasible reference solution for further fixings

The reference solution should be stored in the solptr. The result pointer can be used to indicate either

SCIP_SUCCESS or
SCIP_DIDNOTFIND

Definition at line 279 of file heur_alns.c.

Referenced by DECL_NHFREE(), and DECL_VARFIXINGS().

◆ DECL_NHDEACTIVATE

#define DECL_NHDEACTIVATE ( x )

Value:

SCIP_RETCODE x (\
   SCIP*                 scip,               /**< SCIP data structure */  \
   SCIP_Bool*            deactivate          /**< pointer to store whether the neighborhood should be deactivated (TRUE) for an instance */ \
   )

callback function to deactivate neighborhoods on problems where they are irrelevant

Definition at line 287 of file heur_alns.c.

Referenced by DECL_NHDEACTIVATE(), and DECL_NHREFSOL().

◆ NHISTENTRIES

#define NHISTENTRIES 7

Definition at line 304 of file heur_alns.c.

Referenced by neighborhoodStatsReset(), and printNeighborhoodStatistics().

Typedef Documentation

◆ DATA_CROSSOVER

typedef struct data_crossover DATA_CROSSOVER

crossover neighborhood data structure

Definition at line 207 of file heur_alns.c.

◆ DATA_MUTATION

typedef struct data_mutation DATA_MUTATION

mutation neighborhood data structure

Definition at line 209 of file heur_alns.c.

◆ DATA_DINS

typedef struct data_dins DATA_DINS

dins neighborhood data structure

Definition at line 211 of file heur_alns.c.

◆ NH_FIXINGRATE

typedef struct NH_FixingRate NH_FIXINGRATE

Definition at line 213 of file heur_alns.c.

◆ NH_STATS

typedef struct NH_Stats NH_STATS

fixing rate data structure neighborhood statistics data structure

Definition at line 215 of file heur_alns.c.

◆ NH

typedef struct Nh NH

neighborhood data structure

Definition at line 217 of file heur_alns.c.

◆ VARPRIO

typedef struct VarPrio VARPRIO

Definition at line 223 of file heur_alns.c.

◆ HISTINDEX

typedef enum HistIndex HISTINDEX

Definition at line 303 of file heur_alns.c.

◆ SOLVELIMITS

typedef struct SolveLimits SOLVELIMITS

Definition at line 450 of file heur_alns.c.

Enumeration Type Documentation

◆ HistIndex

enum HistIndex

sub-SCIP status code enumerator

Enumerator
HIDX_OPT	sub-SCIP was solved to optimality
HIDX_USR	sub-SCIP was user interrupted
HIDX_NODELIM	sub-SCIP reached the node limit
HIDX_STALLNODE	sub-SCIP reached the stall node limit
HIDX_INFEAS	sub-SCIP was infeasible
HIDX_SOLLIM	sub-SCIP reached the solution limit
HIDX_OTHER	sub-SCIP reached none of the above codes

Definition at line 293 of file heur_alns.c.

Function Documentation

◆ resetFixingRate()

static SCIP_RETCODE resetFixingRate	(	SCIP *	scip,
		NH_FIXINGRATE *	fixingrate
	)

static

Reset target fixing rate

Parameters

scip	SCIP data structure
fixingrate	heuristic fixing rate

Definition at line 471 of file heur_alns.c.

References FIXINGRATE_STARTINC, NH_FixingRate::increment, NH_FixingRate::maxfixingrate, NULL, resetCurrentNeighborhood(), SCIP_OKAY, and NH_FixingRate::targetfixingrate.

Referenced by SCIP_DECL_HEURINIT().

◆ resetCurrentNeighborhood()

static void resetCurrentNeighborhood ( SCIP_HEURDATA * heurdata )

static

reset the currently active neighborhood

Definition at line 488 of file heur_alns.c.

References NULL, and updateFixingRateIncrement().

Referenced by resetFixingRate(), SCIP_DECL_HEUREXEC(), and SCIP_DECL_HEURINITSOL().

◆ updateFixingRateIncrement()

static void updateFixingRateIncrement ( NH_FIXINGRATE * fx )

static

update increment for fixing rate

Parameters

fx	fixing rate

Definition at line 499 of file heur_alns.c.

References FIXINGRATE_DECAY, increaseFixingRate(), NH_FixingRate::increment, LRATEMIN, and MAX.

Referenced by resetCurrentNeighborhood(), and updateFixingRate().

◆ increaseFixingRate()

static void increaseFixingRate ( NH_FIXINGRATE * fx )

static

increase fixing rate

decrease also the rate by which the target fixing rate is adjusted

Parameters

fx	fixing rate

Definition at line 513 of file heur_alns.c.

References decreaseFixingRate(), NH_FixingRate::increment, NH_FixingRate::maxfixingrate, MIN, and NH_FixingRate::targetfixingrate.

Referenced by updateFixingRate(), and updateFixingRateIncrement().

◆ decreaseFixingRate()

static void decreaseFixingRate ( NH_FIXINGRATE * fx )

static

decrease fixing rate

decrease also the rate by which the target fixing rate is adjusted

Parameters

fx	fixing rate

Definition at line 526 of file heur_alns.c.

References NH_FixingRate::increment, MAX, NH_FixingRate::minfixingrate, NH_FixingRate::targetfixingrate, and updateFixingRate().

Referenced by increaseFixingRate(), and updateFixingRate().

◆ updateFixingRate()

static void updateFixingRate	(	SCIP *	scip,
		NH *	neighborhood,
		SCIP_STATUS	subscipstatus,
		NH_STATS *	runstats
	)

static

update fixing rate based on the results of the current run

Parameters

scip	SCIP data structure
neighborhood	neighborhood
subscipstatus	status of the sub-SCIP run
runstats	run statistics for this run

Definition at line 536 of file heur_alns.c.

References decreaseFixingRate(), Nh::fixingrate, increaseFixingRate(), increaseTargetNodeLimit(), NH_Stats::nbestsolsfound, SCIP_STATUS_BESTSOLLIMIT, SCIP_STATUS_GAPLIMIT, SCIP_STATUS_INFEASIBLE, SCIP_STATUS_INFORUNBD, SCIP_STATUS_MEMLIMIT, SCIP_STATUS_NODELIMIT, SCIP_STATUS_OPTIMAL, SCIP_STATUS_RESTARTLIMIT, SCIP_STATUS_SOLLIMIT, SCIP_STATUS_STALLNODELIMIT, SCIP_STATUS_TERMINATE, SCIP_STATUS_TIMELIMIT, SCIP_STATUS_TOTALNODELIMIT, SCIP_STATUS_UNBOUNDED, SCIP_STATUS_UNKNOWN, SCIP_STATUS_USERINTERRUPT, and updateFixingRateIncrement().

Referenced by decreaseFixingRate(), and SCIP_DECL_HEUREXEC().

◆ increaseTargetNodeLimit()

static void increaseTargetNodeLimit ( SCIP_HEURDATA * heurdata )

static

increase target node limit

Parameters

heurdata heuristic data

Definition at line 582 of file heur_alns.c.

References resetTargetNodeLimit(), and SCIP_Longint.

Referenced by updateFixingRate(), and updateTargetNodeLimit().

◆ resetTargetNodeLimit()

static void resetTargetNodeLimit ( SCIP_HEURDATA * heurdata )

static

reset target node limit

Parameters

heurdata heuristic data

Definition at line 595 of file heur_alns.c.

References updateTargetNodeLimit().

Referenced by increaseTargetNodeLimit(), and SCIP_DECL_HEURINITSOL().

◆ updateTargetNodeLimit()

static void updateTargetNodeLimit	(	SCIP_HEURDATA *	heurdata,
		NH_STATS *	runstats,
		SCIP_STATUS	subscipstatus
	)

static

update target node limit based on the current run results

Parameters

heurdata	heuristic data
runstats	statistics of the run
subscipstatus	status of the sub-SCIP run

Definition at line 604 of file heur_alns.c.

References increaseTargetNodeLimit(), NH_Stats::nbestsolsfound, resetMinimumImprovement(), SCIP_STATUS_BESTSOLLIMIT, SCIP_STATUS_GAPLIMIT, SCIP_STATUS_INFEASIBLE, SCIP_STATUS_INFORUNBD, SCIP_STATUS_MEMLIMIT, SCIP_STATUS_NODELIMIT, SCIP_STATUS_OPTIMAL, SCIP_STATUS_RESTARTLIMIT, SCIP_STATUS_SOLLIMIT, SCIP_STATUS_STALLNODELIMIT, SCIP_STATUS_TERMINATE, SCIP_STATUS_TIMELIMIT, SCIP_STATUS_TOTALNODELIMIT, SCIP_STATUS_UNBOUNDED, SCIP_STATUS_UNKNOWN, and SCIP_STATUS_USERINTERRUPT.

Referenced by resetTargetNodeLimit(), and SCIP_DECL_HEUREXEC().

◆ resetMinimumImprovement()

static void resetMinimumImprovement ( SCIP_HEURDATA * heurdata )

static

reset the minimum improvement for the sub-SCIPs

Parameters

heurdata heuristic data

Definition at line 641 of file heur_alns.c.

References increaseMinimumImprovement(), and NULL.

Referenced by SCIP_DECL_HEURINITSOL(), and updateTargetNodeLimit().

◆ increaseMinimumImprovement()

static void increaseMinimumImprovement ( SCIP_HEURDATA * heurdata )

static

increase minimum improvement for the sub-SCIPs

Parameters

heurdata heuristic data

Definition at line 651 of file heur_alns.c.

References decreaseMinimumImprovement(), MIN, MINIMPROVEFAC, and NULL.

Referenced by resetMinimumImprovement(), and updateMinimumImprovement().

◆ decreaseMinimumImprovement()

static void decreaseMinimumImprovement ( SCIP_HEURDATA * heurdata )

static

decrease the minimum improvement for the sub-SCIPs

Parameters

heurdata heuristic data

Definition at line 663 of file heur_alns.c.

References MAX, MINIMPROVEFAC, NULL, SCIPdebugMessage, and updateMinimumImprovement().

Referenced by increaseMinimumImprovement(), and updateMinimumImprovement().

◆ updateMinimumImprovement()

static void updateMinimumImprovement	(	SCIP_HEURDATA *	heurdata,
		SCIP_STATUS	subscipstatus,
		NH_STATS *	runstats
	)

static

update the minimum improvement based on the status of the sub-SCIP

Parameters

heurdata	heuristic data
subscipstatus	status of the sub-SCIP run
runstats	run statistics for this run

Definition at line 676 of file heur_alns.c.

References decreaseMinimumImprovement(), increaseMinimumImprovement(), NH_Stats::nbestsolsfound, neighborhoodStatsReset(), NULL, SCIP_STATUS_BESTSOLLIMIT, SCIP_STATUS_GAPLIMIT, SCIP_STATUS_INFEASIBLE, SCIP_STATUS_INFORUNBD, SCIP_STATUS_MEMLIMIT, SCIP_STATUS_NODELIMIT, SCIP_STATUS_OPTIMAL, SCIP_STATUS_RESTARTLIMIT, SCIP_STATUS_SOLLIMIT, SCIP_STATUS_STALLNODELIMIT, SCIP_STATUS_TERMINATE, SCIP_STATUS_TIMELIMIT, SCIP_STATUS_TOTALNODELIMIT, SCIP_STATUS_UNBOUNDED, SCIP_STATUS_UNKNOWN, and SCIP_STATUS_USERINTERRUPT.

Referenced by decreaseMinimumImprovement(), and SCIP_DECL_HEUREXEC().

◆ neighborhoodStatsReset()

static SCIP_RETCODE neighborhoodStatsReset	(	SCIP *	scip,
		NH_STATS *	stats
	)

static

Reset neighborhood statistics

Parameters

scip	SCIP data structure
stats	neighborhood statistics

Definition at line 725 of file heur_alns.c.

References alnsIncludeNeighborhood(), BMSclearMemoryArray, NH_Stats::nbestsolsfound, NH_Stats::nfixings, NHISTENTRIES, NH_Stats::nruns, NH_Stats::nrunsbestsol, NH_Stats::nsolsfound, NULL, SCIP_CALL, SCIP_OKAY, SCIPresetClock(), NH_Stats::setupclock, NH_Stats::statushist, NH_Stats::submipclock, and NH_Stats::usednodes.

Referenced by SCIP_DECL_HEURINIT(), and updateMinimumImprovement().

◆ alnsIncludeNeighborhood()

static SCIP_RETCODE alnsIncludeNeighborhood	(	SCIP *	scip,
		SCIP_HEURDATA *	heurdata,
		NH **	neighborhood,
		const char *	name,
		SCIP_Real	minfixingrate,
		SCIP_Real	maxfixingrate,
		SCIP_Bool	active,
		SCIP_Real	priority,
		DECL_VARFIXINGS((*varfixings))	,
		DECL_CHANGESUBSCIP((*changesubscip))	,
		DECL_NHINIT((*nhinit))	,
		DECL_NHEXIT((*nhexit))	,
		DECL_NHFREE((*nhfree))	,
		DECL_NHREFSOL((*nhrefsol))	,
		DECL_NHDEACTIVATE((*nhdeactivate))
	)

static

create a neighborhood of the specified name and include it into the ALNS heuristic

Parameters

scip	SCIP data structure
heurdata	heuristic data of the ALNS heuristic
neighborhood	pointer to store the neighborhood
name	name for this neighborhood
minfixingrate	default value for minfixingrate parameter of this neighborhood
maxfixingrate	default value for maxfixingrate parameter of this neighborhood
active	default value for active parameter of this neighborhood
priority	positive call priority to initialize bandit algorithms

Definition at line 750 of file heur_alns.c.

References active, alnsFreeNeighborhood(), BMSduplicateMemoryArray, NULL, SCIP_ALLOC, SCIP_CALL, SCIP_MAXSTRLEN, SCIP_OKAY, SCIPaddBoolParam(), SCIPaddRealParam(), SCIPallocBlockMemory, SCIPcreateClock(), SCIPsnprintf(), and TRUE.

Referenced by includeNeighborhoods(), and neighborhoodStatsReset().

◆ alnsFreeNeighborhood()

static SCIP_RETCODE alnsFreeNeighborhood	(	SCIP *	scip,
		NH **	neighborhood
	)

static

release all data and free neighborhood

Parameters

scip	SCIP data structure
neighborhood	pointer to neighborhood that should be freed

Definition at line 813 of file heur_alns.c.

References BMSfreeMemoryArray, Nh::name, neighborhoodInit(), NULL, SCIP_CALL, SCIP_OKAY, SCIPfreeBlockMemory, SCIPfreeClock(), NH_Stats::setupclock, Nh::stats, and NH_Stats::submipclock.

Referenced by alnsIncludeNeighborhood(), and SCIP_DECL_HEURFREE().

◆ neighborhoodInit()

static SCIP_RETCODE neighborhoodInit	(	SCIP *	scip,
		NH *	neighborhood
	)

static

initialize neighborhood specific data

Parameters

scip	SCIP data structure
neighborhood	neighborhood to initialize

Definition at line 844 of file heur_alns.c.

References neighborhoodExit(), NULL, SCIP_CALL, and SCIP_OKAY.

Referenced by alnsFreeNeighborhood(), and SCIP_DECL_HEURINIT().

◆ neighborhoodExit()

static SCIP_RETCODE neighborhoodExit	(	SCIP *	scip,
		NH *	neighborhood
	)

static

deinitialize neighborhood specific data

Parameters

scip	SCIP data structure
neighborhood	neighborhood to initialize

Definition at line 863 of file heur_alns.c.

References NULL, SCIP_CALL, SCIP_OKAY, and transferSolution().

Referenced by neighborhoodInit(), and SCIP_DECL_HEUREXIT().

◆ transferSolution()

static SCIP_RETCODE transferSolution	(	SCIP *	subscip,
		SCIP_EVENTDATA *	eventdata
	)

static

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

Parameters

subscip	SCIP data structure of the subproblem
eventdata	event handler data

Definition at line 881 of file heur_alns.c.

References FALSE, NH_Stats::nbestsolsfound, NH_Stats::newupperbound, NH_Stats::nsolsfound, NULL, SCIP_Bool, SCIP_CALL, SCIP_DECL_EVENTEXEC(), SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPcheckSol(), SCIPcreateSol(), SCIPfreeBufferArray, SCIPfreeSol(), SCIPgetBestSol(), SCIPgetCutoffbound(), SCIPgetNOrigVars(), SCIPgetSolTransObj(), SCIPgetSolVals(), SCIPgetUpperbound(), SCIPgetVarsData(), SCIPsetSolVals(), SCIPtrySolFree(), and TRUE.

Referenced by neighborhoodExit(), and SCIP_DECL_EVENTEXEC().

◆ SCIP_DECL_EVENTEXEC()

static SCIP_DECL_EVENTEXEC ( eventExecAlns )

static

execution callback of the event handler

transfer new solutions or interrupt the solving process manually

Definition at line 976 of file heur_alns.c.

References EVENTHDLR_NAME, initRunStats(), NULL, SCIP_CALL, SCIP_EVENTTYPE_ALNS, SCIP_EVENTTYPE_BESTSOLFOUND, SCIP_EVENTTYPE_LPSOLVED, SCIP_EVENTTYPE_SOLFOUND, SCIP_LONGINT_FORMAT, SCIP_OKAY, SCIPdebugMsg, SCIPeventGetType(), SCIPeventhdlrGetName(), SCIPgetNLPs(), SCIPinterruptSolve(), and transferSolution().

Referenced by transferSolution().

◆ initRunStats()

static void initRunStats	(	SCIP *	scip,
		NH_STATS *	stats
	)

static

initialize neighborhood statistics before the next run

Parameters

scip	SCIP data structure
stats	run statistics

Definition at line 1010 of file heur_alns.c.

References NH_Stats::nbestsolsfound, NH_Stats::newupperbound, NH_Stats::nfixings, NH_Stats::nsolsfound, NH_Stats::oldupperbound, SCIPgetUpperbound(), updateRunStats(), and NH_Stats::usednodes.

Referenced by SCIP_DECL_EVENTEXEC(), and SCIP_DECL_HEUREXEC().

◆ updateRunStats()

static void updateRunStats	(	SCIP *	scip,
		NH_STATS *	stats,
		SCIP *	subscip
	)

static

update run stats after the sub SCIP was solved

Parameters

scip	SCIP data structure
stats	run statistics
subscip	sub-SCIP instance, or NULL

Definition at line 1025 of file heur_alns.c.

References getHistIndex(), NULL, SCIPgetNNodes(), SCIPisTransformed(), and NH_Stats::usednodes.

Referenced by initRunStats(), and SCIP_DECL_HEUREXEC().

◆ getHistIndex()

static int getHistIndex ( SCIP_STATUS subscipstatus )

static

get the histogram index for this status

Parameters

subscipstatus sub-SCIP status

Definition at line 1040 of file heur_alns.c.

References HIDX_INFEAS, HIDX_NODELIM, HIDX_OPT, HIDX_OTHER, HIDX_SOLLIM, HIDX_STALLNODE, HIDX_USR, printNeighborhoodStatistics(), SCIP_STATUS_BESTSOLLIMIT, SCIP_STATUS_INFEASIBLE, SCIP_STATUS_NODELIMIT, SCIP_STATUS_OPTIMAL, SCIP_STATUS_SOLLIMIT, SCIP_STATUS_STALLNODELIMIT, and SCIP_STATUS_USERINTERRUPT.

Referenced by updateNeighborhoodStats(), and updateRunStats().

◆ printNeighborhoodStatistics()

static void printNeighborhoodStatistics	(	SCIP *	scip,
		SCIP_HEURDATA *	heurdata,
		FILE *	file
	)

static

print neighborhood statistics

Parameters

scip	SCIP data structure
heurdata	heuristic data
file	file handle, or NULL for standard out

Definition at line 1066 of file heur_alns.c.

References Nh::fixingrate, HIDX_INFEAS, HIDX_NODELIM, HIDX_OPT, HIDX_OTHER, HIDX_SOLLIM, HIDX_STALLNODE, HIDX_USR, Nh::name, NH_Stats::nbestsolsfound, NHISTENTRIES, NH_Stats::nruns, NH_Stats::nsolsfound, NULL, SCIP_LONGINT_FORMAT, SCIP_Real, SCIPgetClockTime(), SCIPgetConfidenceBoundUcb(), SCIPgetProbabilityExp3(), SCIPgetWeightsEpsgreedy(), SCIPinfoMessage(), NH_Stats::setupclock, Nh::stats, NH_Stats::statushist, NH_Stats::submipclock, NH_FixingRate::targetfixingrate, updateNeighborhoodStats(), and NH_Stats::usednodes.

Referenced by getHistIndex(), and SCIP_DECL_TABLEOUTPUT().

◆ updateNeighborhoodStats()

static void updateNeighborhoodStats	(	SCIP *	scip,
		NH_STATS *	runstats,
		NH *	neighborhood,
		SCIP_STATUS	subscipstatus
	)

static

update the statistics of the neighborhood based on the sub-SCIP run

Parameters

scip	SCIP data structure
runstats	run statistics
neighborhood	the selected neighborhood
subscipstatus	status of the sub-SCIP solve

Definition at line 1135 of file heur_alns.c.

References DEFAULT_BESTSOLWEIGHT, getHistIndex(), NH_Stats::nbestsolsfound, NH_Stats::nruns, NH_Stats::nrunsbestsol, NH_Stats::nsolsfound, SCIP_DECL_SORTINDCOMP(), Nh::stats, NH_Stats::statushist, and NH_Stats::usednodes.

Referenced by printNeighborhoodStatistics(), and SCIP_DECL_HEUREXEC().

◆ SCIP_DECL_SORTINDCOMP()

static SCIP_DECL_SORTINDCOMP ( sortIndCompAlns )

static

sort callback for variable pointers using the ALNS variable prioritization

the variable prioritization works hierarchically as follows. A variable a has the higher priority over b iff

variable distances should be used and a has a smaller distance than b
variable reduced costs should be used and a has a smaller score than b
variable pseudo costs should be used and a has a smaller score than b
based on previously assigned random scores

Note: : distances are context-based. For fixing more variables, distances are initialized from the already fixed variables. For unfixing variables, distances are initialized starting from the unfixed variables

Definition at line 1176 of file heur_alns.c.

References VarPrio::distances, getVariableRedcostScore(), NULL, VarPrio::pscostscores, VarPrio::randscores, VarPrio::redcostscores, SCIP_Real, VarPrio::usedistances, VarPrio::usepscost, and VarPrio::useredcost.

Referenced by updateNeighborhoodStats().

◆ getVariableRedcostScore()

static SCIP_Real getVariableRedcostScore	(	SCIP *	scip,
		SCIP_VAR *	var,
		SCIP_Real	refsolval,
		SCIP_Bool	uselocalredcost
	)

static

Compute the reduced cost score for this variable in the reference solution

Parameters

scip	SCIP data structure
var	the variable for which the score should be computed
refsolval	solution value in reference solution
uselocalredcost	should local reduced costs be used for generic (un)fixing?

Definition at line 1245 of file heur_alns.c.

References getVariablePscostScore(), MAX, NULL, REALABS, SCIP_LPSOLSTAT_OPTIMAL, SCIP_Real, SCIP_VARSTATUS_COLUMN, SCIPgetLPSolstat(), SCIPgetVarRedcost(), SCIPhasCurrentNodeLP(), SCIPinfinity(), SCIPisDualfeasNegative(), SCIPisDualfeasPositive(), SCIPisDualfeasZero(), SCIPisFeasIntegral(), SCIPisFeasNegative(), SCIPisFeasPositive(), SCIPisInfinity(), SCIPvarGetBestRootRedcost(), SCIPvarGetBestRootSol(), SCIPvarGetLPSol(), and SCIPvarGetStatus().

Referenced by alnsFixMoreVariables(), alnsUnfixVariables(), and SCIP_DECL_SORTINDCOMP().

◆ getVariablePscostScore()

static SCIP_Real getVariablePscostScore	(	SCIP *	scip,
		SCIP_VAR *	var,
		SCIP_Real	refsolval
	)

static

get the pseudo cost score of this variable with respect to the reference solution

Parameters

scip	SCIP data structure
var	the variable for which the score should be computed
refsolval	solution value in reference solution

Definition at line 1298 of file heur_alns.c.

References NULL, SCIP_Real, SCIP_VARSTATUS_COLUMN, SCIPgetVarPseudocostVal(), SCIPisEQ(), SCIPvarGetRootSol(), SCIPvarGetStatus(), and tryAdd2variableBuffer().

Referenced by alnsFixMoreVariables(), alnsUnfixVariables(), and getVariableRedcostScore().

◆ tryAdd2variableBuffer()

static void tryAdd2variableBuffer	(	SCIP *	scip,
		SCIP_VAR *	var,
		SCIP_Real	val,
		SCIP_VAR **	varbuf,
		SCIP_Real *	valbuf,
		int *	nfixings,
		SCIP_Bool	integer
	)

static

add variable and solution value to buffer data structure for variable fixings. The method checks if the value still lies within the variable bounds. The value stays unfixed otherwise.

Parameters

scip	SCIP data structure
var	(source) SCIP variable that should be added to the buffer
val	fixing value for this variable
varbuf	variable buffer to store variables that should be fixed
valbuf	value buffer to store fixing values
nfixings	pointer to number of fixed buffer variables, will be increased by 1
integer	is this an integer variable?

Definition at line 1326 of file heur_alns.c.

References neighborhoodGetRefsol(), NH_Stats::nfixings, SCIPfloor(), SCIPgetNVars(), SCIPisFeasIntegral(), SCIPvarGetLbGlobal(), SCIPvarGetUbGlobal(), and SCIPvarIsIntegral().

Referenced by alnsFixMoreVariables(), DECL_VARFIXINGS(), fixMatchingSolutionValues(), and getVariablePscostScore().

◆ neighborhoodGetRefsol()

static SCIP_RETCODE neighborhoodGetRefsol	(	SCIP *	scip,
		NH *	neighborhood,
		SCIP_SOL **	solptr
	)

static

query neighborhood for a reference solution for further fixings

Parameters

scip	SCIP data structure
neighborhood	ALNS neighborhood data structure
solptr	solution pointer

Definition at line 1357 of file heur_alns.c.

References alnsFixMoreVariables(), NULL, SCIP_CALL, SCIP_DIDNOTFIND, and SCIP_OKAY.

Referenced by neighborhoodFixVariables(), and tryAdd2variableBuffer().

◆ alnsFixMoreVariables()

static SCIP_RETCODE alnsFixMoreVariables	(	SCIP *	scip,
		SCIP_HEURDATA *	heurdata,
		SCIP_SOL *	refsol,
		SCIP_VAR **	varbuf,
		SCIP_Real *	valbuf,
		int *	nfixings,
		int	ntargetfixings,
		SCIP_Bool *	success
	)

static

fix additional variables found in feasible reference solution if the ones that the neighborhood found were not enough

use not always the best solution for the values, but a reference solution provided by the neighborhood itself

Note: it may happen that the target fixing rate is not completely reached. This is the case if intermediate, dual reductions render the solution values of the reference solution infeasible for the current, global variable bounds.

Parameters

scip	SCIP data structure
heurdata	heuristic data of the ALNS neighborhood
refsol	feasible reference solution for more variable fixings
varbuf	buffer array to store variables to fix
valbuf	buffer array to store fixing values
nfixings	pointer to store the number of fixings
ntargetfixings	number of required target fixings
success	pointer to store whether the target fixings have been successfully reached

Definition at line 1391 of file heur_alns.c.

References b, BMSclearMemoryArray, createBandit(), VarPrio::distances, FALSE, getVariablePscostScore(), getVariableRedcostScore(), MIN, NH_Stats::nfixings, NULL, VarPrio::pscostscores, VarPrio::randscores, VarPrio::redcostscores, VarPrio::scip, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPbanditGetRandnumgen(), SCIPdebugMsg, SCIPfreeBufferArray, SCIPgetSolVals(), SCIPgetVarsData(), SCIPrandomGetReal(), SCIPselectInd(), SCIPvarGetLbGlobal(), SCIPvarGetName(), SCIPvarGetProbindex(), SCIPvarGetUbGlobal(), SCIPvariablegraphBreadthFirst(), TRUE, tryAdd2variableBuffer(), VarPrio::usedistances, VarPrio::usepscost, and VarPrio::useredcost.

Referenced by neighborhoodFixVariables(), and neighborhoodGetRefsol().

◆ createBandit()

static SCIP_RETCODE createBandit	(	SCIP *	scip,
		SCIP_HEURDATA *	heurdata,
		SCIP_Real *	priorities,
		unsigned int	initseed
	)

static

create the bandit algorithm for the heuristic depending on the user parameter

Parameters

scip	SCIP data structure
heurdata	heuristic data structure
priorities	call priorities for active neighborhoods
initseed	initial random seed

Definition at line 1561 of file heur_alns.c.

References FALSE, SCIP_CALL, SCIP_DECL_HEURCOPY(), SCIP_INVALIDDATA, SCIP_OKAY, SCIPcreateBanditEpsgreedy(), SCIPcreateBanditExp3(), SCIPcreateBanditUcb(), and SCIPerrorMessage.

Referenced by alnsFixMoreVariables(), and SCIP_DECL_HEURINITSOL().

◆ SCIP_DECL_HEURCOPY()

static SCIP_DECL_HEURCOPY ( heurCopyAlns )

static

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

Definition at line 1599 of file heur_alns.c.

References alnsUnfixVariables(), HEUR_NAME, NULL, SCIP_CALL, SCIP_OKAY, SCIPheurGetName(), and SCIPincludeHeurAlns().

Referenced by createBandit().

◆ alnsUnfixVariables()

static SCIP_RETCODE alnsUnfixVariables	(	SCIP *	scip,
		SCIP_HEURDATA *	heurdata,
		SCIP_VAR **	varbuf,
		SCIP_Real *	valbuf,
		int *	nfixings,
		int	ntargetfixings,
		SCIP_Bool *	success
	)

static

unfix some of the variables because there are too many fixed

a variable is ideally unfixed if it is close to other unfixed variables and fixing it has a high reduced cost impact

Parameters

scip	SCIP data structure
heurdata	heuristic data of the ALNS neighborhood
varbuf	buffer array to store variables to fix
valbuf	buffer array to store fixing values
nfixings	pointer to store the number of fixings
ntargetfixings	number of required target fixings
success	pointer to store whether the target fixings have been successfully reached

Definition at line 1617 of file heur_alns.c.

References BMSclearMemoryArray, VarPrio::distances, FALSE, getVariablePscostScore(), getVariableRedcostScore(), neighborhoodFixVariables(), NH_Stats::nfixings, NULL, VarPrio::pscostscores, VarPrio::randscores, VarPrio::redcostscores, VarPrio::scip, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPbanditGetRandnumgen(), SCIPdebugMsg, SCIPduplicateBufferArray, SCIPfreeBufferArray, SCIPgetNBinVars(), SCIPgetNIntVars(), SCIPgetNVars(), SCIPgetVars(), SCIPrandomGetReal(), SCIPselectDownInd(), SCIPvarGetName(), SCIPvarGetProbindex(), SCIPvariablegraphBreadthFirst(), TRUE, VarPrio::usedistances, VarPrio::usepscost, and VarPrio::useredcost.

Referenced by neighborhoodFixVariables(), and SCIP_DECL_HEURCOPY().

◆ neighborhoodFixVariables()

static SCIP_RETCODE neighborhoodFixVariables	(	SCIP *	scip,
		SCIP_HEURDATA *	heurdata,
		NH *	neighborhood,
		SCIP_VAR **	varbuf,
		SCIP_Real *	valbuf,
		int *	nfixings,
		SCIP_RESULT *	result
	)

static

call variable fixing callback for this neighborhood and orchestrate additional variable fixings, if necessary

Parameters

scip	SCIP data structure
heurdata	heuristic data of the ALNS neighborhood
neighborhood	neighborhood data structure
varbuf	buffer array to keep variables that should be fixed
valbuf	buffer array to keep fixing values
nfixings	pointer to store the number of variable fixings
result	pointer to store the result of the fixing operation

Definition at line 1764 of file heur_alns.c.

References alnsFixMoreVariables(), alnsUnfixVariables(), FALSE, Nh::fixingrate, MAX, MIN, neighborhoodChangeSubscip(), neighborhoodGetRefsol(), NH_Stats::nfixings, NULL, SCIP_Bool, SCIP_CALL, SCIP_DIDNOTFIND, SCIP_DIDNOTRUN, SCIP_OKAY, SCIP_Real, SCIP_SUCCESS, SCIPdebugMsg, SCIPgetNBinVars(), SCIPgetNIntVars(), and NH_FixingRate::targetfixingrate.

Referenced by alnsUnfixVariables(), and SCIP_DECL_HEUREXEC().

◆ neighborhoodChangeSubscip()

static SCIP_RETCODE neighborhoodChangeSubscip	(	SCIP *	sourcescip,
		SCIP *	targetscip,
		NH *	neighborhood,
		SCIP_VAR **	targetvars,
		int *	ndomchgs,
		int *	nchgobjs,
		int *	naddedconss,
		SCIP_Bool *	success
	)

static

change the sub-SCIP by restricting variable domains, changing objective coefficients, or adding constraints

Parameters

sourcescip	source SCIP data structure
targetscip	target SCIP data structure
neighborhood	neighborhood
targetvars	array of target SCIP variables aligned with source SCIP variables
ndomchgs	pointer to store the number of variable domain changes
nchgobjs	pointer to store the number of changed objective coefficients
naddedconss	pointer to store the number of added constraints
success	pointer to store whether the sub-SCIP has been successfully modified

Definition at line 1862 of file heur_alns.c.

References FALSE, NULL, SCIP_CALL, SCIP_OKAY, setLimits(), and TRUE.

Referenced by neighborhoodFixVariables(), and SCIP_DECL_HEUREXEC().

◆ setLimits()

static SCIP_RETCODE setLimits	(	SCIP *	subscip,
		SOLVELIMITS *	solvelimits
	)

static

set sub-SCIP solving limits

Parameters

subscip	SCIP data structure
solvelimits	pointer to solving limits data structure

Definition at line 1902 of file heur_alns.c.

References determineLimits(), SolveLimits::memorylimit, SolveLimits::nodelimit, NULL, SCIP_CALL, SCIP_OKAY, SCIPsetLongintParam(), SCIPsetRealParam(), SolveLimits::stallnodes, and SolveLimits::timelimit.

Referenced by neighborhoodChangeSubscip(), and setupSubScip().

◆ determineLimits()

static SCIP_RETCODE determineLimits	(	SCIP *	scip,
		SCIP_HEUR *	heur,
		SOLVELIMITS *	solvelimits,
		SCIP_Bool *	runagain
	)

static

determine limits for a sub-SCIP

Parameters

scip	SCIP data structure
heur	this heuristic
solvelimits	pointer to solving limits data structure
runagain	can we solve another sub-SCIP with these limits

Definition at line 1922 of file heur_alns.c.

References FALSE, getBandit(), SolveLimits::memorylimit, MIN, SolveLimits::nodelimit, NULL, SCIP_CALL, SCIP_Longint, SCIP_OKAY, SCIP_Real, SCIPgetMemExternEstim(), SCIPgetMemUsed(), SCIPgetNNodes(), SCIPgetRealParam(), SCIPgetSolvingTime(), SCIPheurGetData(), SCIPheurGetNBestSolsFound(), SCIPheurGetNCalls(), SCIPisInfinity(), SolveLimits::stallnodes, and SolveLimits::timelimit.

Referenced by SCIP_DECL_HEUREXEC(), and setLimits().

◆ getBandit()

static SCIP_BANDIT* getBandit ( SCIP_HEURDATA * heurdata )

static

return the bandit algorithm that should be used

Parameters

heurdata heuristic data of the ALNS neighborhood

Definition at line 1985 of file heur_alns.c.

References NULL, and selectNeighborhood().

Referenced by determineLimits(), selectNeighborhood(), and updateBanditAlgorithm().

◆ selectNeighborhood()

static SCIP_RETCODE selectNeighborhood	(	SCIP *	scip,
		SCIP_HEURDATA *	heurdata,
		int *	neighborhoodidx
	)

static

select a neighborhood depending on the selected bandit algorithm

Parameters

scip	SCIP data structure
heurdata	heuristic data of the ALNS neighborhood
neighborhoodidx	pointer to store the selected neighborhood index

Definition at line 1995 of file heur_alns.c.

References getBandit(), getReward(), NULL, SCIP_CALL, SCIP_OKAY, and SCIPbanditSelect().

Referenced by getBandit(), and SCIP_DECL_HEUREXEC().

◆ getReward()

static SCIP_RETCODE getReward	(	SCIP *	scip,
		SCIP_HEURDATA *	heurdata,
		NH_STATS *	runstats,
		SCIP_Real *	rewardptr
	)

static

Calculate reward based on the selected reward measure

Parameters

scip	SCIP data structure
heurdata	heuristic data of the ALNS neighborhood
runstats	run statistics
rewardptr	pointer to store the computed reward

Definition at line 2018 of file heur_alns.c.

References MAX, NH_Stats::nbestsolsfound, NH_Stats::newupperbound, NH_Stats::nfixings, NULL, NH_Stats::oldupperbound, SCIP_OKAY, SCIP_Real, SCIPgetLowerbound(), SCIPgetNBinVars(), SCIPgetNIntVars(), SCIPisEQ(), SCIPisInfinity(), updateBanditAlgorithm(), and NH_Stats::usednodes.

Referenced by SCIP_DECL_HEUREXEC(), and selectNeighborhood().

◆ updateBanditAlgorithm()

static SCIP_RETCODE updateBanditAlgorithm	(	SCIP *	scip,
		SCIP_HEURDATA *	heurdata,
		SCIP_Real	reward,
		int	neighborhoodidx
	)

static

update internal bandit algorithm statistics for future draws

Parameters

scip	SCIP data structure
heurdata	heuristic data of the ALNS neighborhood
reward	measured reward
neighborhoodidx	the neighborhood that was chosen

Definition at line 2096 of file heur_alns.c.

References getBandit(), NULL, SCIP_CALL, SCIP_OKAY, SCIPbanditUpdate(), SCIPdebugMsg, and setupSubScip().

Referenced by getReward(), and SCIP_DECL_HEUREXEC().

◆ setupSubScip()

static SCIP_RETCODE setupSubScip	(	SCIP *	scip,
		SCIP *	subscip,
		SCIP_VAR **	subvars,
		SOLVELIMITS *	solvelimits,
		SCIP_HEUR *	heur,
		SCIP_Bool	objchgd
	)

static

set up the sub-SCIP parameters, objective cutoff, and solution limits

Parameters

scip	SCIP data structure
subscip	sub-SCIP data structure
subvars	array of sub-SCIP variables in the order of the main SCIP
solvelimits	pointer to solving limits data structure
heur	this heuristic
objchgd	did the objective change between the source and the target SCIP?

Definition at line 2119 of file heur_alns.c.

References FALSE, MIN, SolveLimits::nodelimit, NULL, SCIP_CALL, SCIP_DECL_HEUREXEC(), SCIP_OKAY, SCIP_PARAMSETTING_FAST, SCIP_PARAMSETTING_OFF, SCIP_Real, SCIP_REAL_FORMAT, SCIPaddCoefLinear(), SCIPaddCons(), SCIPcreateConsLinear(), SCIPdebugMsg, SCIPfindBranchrule(), SCIPfindConshdlr(), SCIPfindNodesel(), SCIPfloor(), SCIPgetLowerbound(), SCIPgetNVars(), SCIPgetUpperbound(), SCIPgetVars(), SCIPheurGetData(), SCIPheurGetNCalls(), SCIPinfinity(), SCIPisFeasZero(), SCIPisInfinity(), SCIPisObjIntegral(), SCIPisParamFixed(), SCIPreleaseCons(), SCIPretransformObj(), SCIPsetBoolParam(), SCIPsetIntParam(), SCIPsetObjlimit(), SCIPsetPresolving(), SCIPsetSeparating(), SCIPsetSubscipsOff(), SCIPsumepsilon(), SCIPvarGetObj(), setLimits(), SolveLimits::stallnodes, SolveLimits::timelimit, and TRUE.

Referenced by SCIP_DECL_HEUREXEC(), and updateBanditAlgorithm().

◆ SCIP_DECL_HEUREXEC()

static SCIP_DECL_HEUREXEC ( heurExecAlns )

static

execution method of primal heuristic

Definition at line 2274 of file heur_alns.c.

References DECL_VARFIXINGS, determineLimits(), EVENTHDLR_DESC, EVENTHDLR_NAME, FALSE, getReward(), initRunStats(), Nh::name, neighborhoodChangeSubscip(), neighborhoodFixVariables(), NH_Stats::nfixings, NNEIGHBORHOODS, SolveLimits::nodelimit, NH_Stats::nruns, NULL, resetCurrentNeighborhood(), SCIP_Bool, SCIP_CALL, SCIP_CALL_ABORT, SCIP_DELAYED, SCIP_DIDNOTFIND, SCIP_DIDNOTRUN, SCIP_EVENTTYPE_ALNS, SCIP_LONGINT_FORMAT, SCIP_LPSOLSTAT_OPTIMAL, SCIP_OKAY, SCIP_Real, SCIP_STATUS_UNKNOWN, SCIP_SUCCESS, SCIPallocBufferArray, SCIPblkmem(), SCIPcatchEvent(), SCIPcopyLargeNeighborhoodSearch(), SCIPcreate(), SCIPdebugMsg, SCIPfree(), SCIPfreeBufferArray, SCIPgetBestSol(), SCIPgetDepth(), SCIPgetLPSolstat(), SCIPgetNNodes(), SCIPgetNSols(), SCIPgetStatus(), SCIPgetVarsData(), SCIPhasCurrentNodeLP(), SCIPhashmapCreate(), SCIPhashmapFree(), SCIPhashmapGetImage(), SCIPheurGetData(), SCIPheurGetFreq(), SCIPheurGetNCalls(), SCIPincludeEventhdlrBasic(), SCIPisStopped(), SCIPprintStatistics(), SCIPsolGetNodenum(), SCIPsolve(), SCIPstartClock(), SCIPstopClock(), SCIPtransformProb(), selectNeighborhood(), NH_Stats::setupclock, setupSubScip(), Nh::stats, NH_Stats::submipclock, TRUE, updateBanditAlgorithm(), updateFixingRate(), updateMinimumImprovement(), updateNeighborhoodStats(), updateRunStats(), updateTargetNodeLimit(), and NH_Stats::usednodes.

Referenced by setupSubScip().

◆ DECL_VARFIXINGS() [1/5]

static DECL_VARFIXINGS ( varFixingsRens )

static

callback to collect variable fixings of RENS

Definition at line 2637 of file heur_alns.c.

References DECL_CHANGESUBSCIP, NH_Stats::nfixings, NULL, SCIP_CALL, SCIP_DELAYED, SCIP_DIDNOTRUN, SCIP_LPSOLSTAT_OPTIMAL, SCIP_OKAY, SCIP_Real, SCIP_SUCCESS, SCIPgetLPSolstat(), SCIPgetSolVal(), SCIPgetVarsData(), SCIPhasCurrentNodeLP(), SCIPisFeasIntegral(), SCIPvarIsBinary(), SCIPvarIsIntegral(), TRUE, and tryAdd2variableBuffer().

◆ DECL_CHANGESUBSCIP() [1/5]

static DECL_CHANGESUBSCIP ( changeSubscipRens )

static

callback for RENS subproblem changes

Definition at line 2683 of file heur_alns.c.

References fixMatchingSolutionValues(), NULL, SCIP_CALL, SCIP_LPSOLSTAT_OPTIMAL, SCIP_OKAY, SCIP_Real, SCIPchgVarLbGlobal(), SCIPchgVarUbGlobal(), SCIPfloor(), SCIPgetLPSolstat(), SCIPgetSolVal(), SCIPgetVarsData(), SCIPhasCurrentNodeLP(), SCIPisFeasIntegral(), SCIPvarGetLbGlobal(), SCIPvarGetUbGlobal(), and TRUE.

◆ fixMatchingSolutionValues()

static SCIP_RETCODE fixMatchingSolutionValues	(	SCIP *	scip,
		SCIP_SOL **	sols,
		int	nsols,
		SCIP_VAR **	vars,
		int	nvars,
		SCIP_VAR **	varbuf,
		SCIP_Real *	valbuf,
		int *	nfixings
	)

static

collect fixings by matching solution values in a collection of solutions for all binary and integer variables, or for a custom set of variables

Parameters

scip	SCIP data structure
sols	array of 2 or more solutions. It is okay for the array to contain one element equal to NULL to represent the current LP solution
nsols	number of solutions in the array
vars	variable array for which solution values must agree
nvars	number of variables, or -1 for all binary and integer variables
varbuf	buffer storage for variable fixings
valbuf	buffer storage for fixing values
nfixings	pointer to store the number of fixings

Definition at line 2726 of file heur_alns.c.

References DECL_VARFIXINGS, NH_Stats::nfixings, NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPgetNBinVars(), SCIPgetSolVal(), SCIPgetVarsData(), SCIPisEQ(), SCIPvarIsBinary(), SCIPvarIsIntegral(), TRUE, and tryAdd2variableBuffer().

Referenced by DECL_CHANGESUBSCIP(), and DECL_VARFIXINGS().

◆ DECL_VARFIXINGS() [2/5]

static DECL_VARFIXINGS ( varFixingsRins )

static

callback to collect variable fixings of RINS

Definition at line 2792 of file heur_alns.c.

References DECL_NHINIT, fixMatchingSolutionValues(), NH_Stats::nfixings, NULL, SCIP_CALL, SCIP_DELAYED, SCIP_DIDNOTRUN, SCIP_LPSOLSTAT_OPTIMAL, SCIP_OKAY, SCIP_SOLORIGIN_ORIGINAL, SCIP_SUCCESS, SCIPgetBestSol(), SCIPgetLPSolstat(), SCIPgetVarsData(), SCIPhasCurrentNodeLP(), and SCIPsolGetOrigin().

◆ DECL_NHINIT() [1/2]

static DECL_NHINIT ( nhInitCrossover )

static

initialization callback for crossover when a new problem is read

Definition at line 2840 of file heur_alns.c.

References Nh::crossover, CROSSOVERSEED, Nh::data, DECL_NHEXIT, NULL, data_crossover::rng, SCIP_CALL, SCIP_OKAY, SCIPcreateRandom(), SCIPfreeRandom(), SCIPgetNVars(), data_crossover::selsol, and TRUE.

◆ DECL_NHEXIT() [1/2]

static DECL_NHEXIT ( nhExitCrossover )

static

deinitialization callback for crossover when exiting a problem

Definition at line 2859 of file heur_alns.c.

References Nh::crossover, Nh::data, DECL_NHFREE, NULL, data_crossover::rng, SCIP_OKAY, and SCIPfreeRandom().

◆ DECL_NHFREE() [1/2]

static DECL_NHFREE ( nhFreeCrossover )

static

deinitialization callback for crossover before SCIP is freed

Definition at line 2874 of file heur_alns.c.

References Nh::crossover, Nh::data, DECL_VARFIXINGS, NULL, SCIP_OKAY, and SCIPfreeBlockMemory.

◆ DECL_VARFIXINGS() [3/5]

static DECL_VARFIXINGS ( varFixingsCrossover )

static

callback to collect variable fixings of crossover

Definition at line 2884 of file heur_alns.c.

References Nh::crossover, Nh::data, DECL_NHREFSOL, fixMatchingSolutionValues(), NH_Stats::nfixings, data_crossover::nsols, NULL, data_crossover::rng, SCIP_CALL, SCIP_DIDNOTRUN, SCIP_OKAY, SCIP_SUCCESS, SCIPallocBufferArray, SCIPfreeBufferArray, SCIPgetNBinVars(), SCIPgetNIntVars(), SCIPgetNSols(), SCIPgetSols(), SCIPrandomGetInt(), and data_crossover::selsol.

◆ DECL_NHREFSOL() [1/2]

static DECL_NHREFSOL ( nhRefsolCrossover )

static

callback for crossover reference solution

Definition at line 2965 of file heur_alns.c.

References Nh::crossover, Nh::data, DECL_NHINIT, NULL, SCIP_DIDNOTFIND, SCIP_OKAY, SCIP_SUCCESS, and data_crossover::selsol.

◆ DECL_NHINIT() [2/2]

static DECL_NHINIT ( nhInitMutation )

static

initialization callback for mutation when a new problem is read

Definition at line 2986 of file heur_alns.c.

References Nh::data, DECL_NHEXIT, Nh::mutation, MUTATIONSEED, NULL, data_mutation::rng, SCIP_CALL, SCIP_OKAY, SCIPallocBlockMemory, SCIPcreateRandom(), SCIPgetNVars(), and TRUE.

◆ DECL_NHEXIT() [2/2]

static DECL_NHEXIT ( nhExitMutation )

static

deinitialization callback for mutation when exiting a problem

Definition at line 3004 of file heur_alns.c.

References Nh::data, DECL_VARFIXINGS, Nh::mutation, NULL, data_mutation::rng, SCIP_OKAY, SCIPfreeBlockMemory, and SCIPfreeRandom().

◆ DECL_VARFIXINGS() [4/5]

static DECL_VARFIXINGS ( varFixingsMutation )

static

callback to collect variable fixings of mutation

Definition at line 3021 of file heur_alns.c.

References addLocalBranchingConstraint(), Nh::data, Nh::fixingrate, Nh::mutation, NH_Stats::nfixings, NULL, data_mutation::rng, SCIP_CALL, SCIP_DIDNOTFIND, SCIP_DIDNOTRUN, SCIP_OKAY, SCIP_Real, SCIP_SUCCESS, SCIPduplicateBufferArray, SCIPfreeBufferArray, SCIPgetBestSol(), SCIPgetSolVal(), SCIPgetVarsData(), SCIPrandomGetInt(), SCIPswapPointers(), NH_FixingRate::targetfixingrate, TRUE, and tryAdd2variableBuffer().

◆ addLocalBranchingConstraint()

static SCIP_RETCODE addLocalBranchingConstraint	(	SCIP *	sourcescip,
		SCIP *	targetscip,
		SCIP_VAR **	subvars,
		int	distance,
		SCIP_Bool *	success,
		int *	naddedconss
	)

static

add local branching constraint

Parameters

sourcescip	source SCIP data structure
targetscip	target SCIP data structure
subvars	array of sub SCIP variables in same order as source SCIP variables
distance	right hand side of the local branching constraint
success	pointer to store of a local branching constraint has been successfully added
naddedconss	pointer to increase the number of added constraints

Definition at line 3099 of file heur_alns.c.

References DECL_CHANGESUBSCIP, FALSE, MAX, NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPaddCons(), SCIPallocBufferArray, SCIPcreateConsBasicLinear(), SCIPfreeBufferArray, SCIPgetBestSol(), SCIPgetNBinVars(), SCIPgetSolVal(), SCIPgetVars(), SCIPinfinity(), SCIPisEQ(), SCIPreleaseCons(), and TRUE.

Referenced by DECL_CHANGESUBSCIP(), and DECL_VARFIXINGS().

◆ DECL_CHANGESUBSCIP() [2/5]

static DECL_CHANGESUBSCIP ( changeSubscipLocalbranching )

static

callback for local branching subproblem changes

Definition at line 3161 of file heur_alns.c.

References addLocalBranchingConstraint(), DECL_CHANGESUBSCIP, SCIP_CALL, SCIP_OKAY, and SCIPgetNBinVars().

◆ DECL_CHANGESUBSCIP() [3/5]

static DECL_CHANGESUBSCIP ( changeSubscipProximity )

static

callback for proximity subproblem changes

Definition at line 3171 of file heur_alns.c.

References DECL_CHANGESUBSCIP, NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPchgVarObj(), SCIPgetBestSol(), SCIPgetSolVal(), SCIPgetVarsData(), and TRUE.

◆ DECL_CHANGESUBSCIP() [4/5]

static DECL_CHANGESUBSCIP ( changeSubscipZeroobjective )

static

callback for zeroobjective subproblem changes

Definition at line 3214 of file heur_alns.c.

References computeIntegerVariableBoundsDins(), FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIPchgVarObj(), SCIPgetNObjVars(), SCIPgetVarsData(), and TRUE.

◆ computeIntegerVariableBoundsDins()

static void computeIntegerVariableBoundsDins	(	SCIP *	scip,
		SCIP_VAR *	var,
		SCIP_Real *	lbptr,
		SCIP_Real *	ubptr
	)

static

compute tightened bounds for integer variables depending on how much the LP and the incumbent solution values differ

Parameters

scip	SCIP data structure of the original problem
var	the variable for which bounds should be computed
lbptr	pointer to store the lower bound in the DINS sub-SCIP
ubptr	pointer to store the upper bound in the DINS sub-SCIP

Definition at line 3242 of file heur_alns.c.

References DECL_VARFIXINGS, MAX, MIN, REALABS, SCIP_Real, SCIP_VARTYPE_INTEGER, SCIPfeasCeil(), SCIPfeasFloor(), SCIPgetBestSol(), SCIPgetSolVal(), SCIPisFeasEQ(), SCIPvarGetLbGlobal(), SCIPvarGetLPSol(), SCIPvarGetType(), and SCIPvarGetUbGlobal().

Referenced by DECL_CHANGESUBSCIP(), and DECL_VARFIXINGS().

◆ DECL_VARFIXINGS() [5/5]

static DECL_VARFIXINGS ( varFixingsDins )

static

callback to collect variable fixings of DINS

Definition at line 3316 of file heur_alns.c.

References BMScopyMemoryArray, computeIntegerVariableBoundsDins(), Nh::data, DECL_CHANGESUBSCIP, Nh::dins, fixMatchingSolutionValues(), MIN, NH_Stats::nfixings, data_dins::npoolsols, NULL, SCIP_CALL, SCIP_DELAYED, SCIP_DIDNOTRUN, SCIP_LPSOLSTAT_OPTIMAL, SCIP_OKAY, SCIP_Real, SCIP_SUCCESS, SCIPallocBufferArray, SCIPcreateSol(), SCIPfreeBufferArray, SCIPfreeSol(), SCIPgetLPSolstat(), SCIPgetNSols(), SCIPgetSols(), SCIPgetVarsData(), SCIPisFeasIntegral(), SCIPsetSolVal(), SCIPvarGetRootSol(), TRUE, and tryAdd2variableBuffer().

◆ DECL_CHANGESUBSCIP() [5/5]

static DECL_CHANGESUBSCIP ( changeSubscipDins )

static

callback for DINS subproblem changes

Definition at line 3397 of file heur_alns.c.

References addLocalBranchingConstraint(), computeIntegerVariableBoundsDins(), DECL_NHFREE, NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPchgVarLbGlobal(), SCIPchgVarUbGlobal(), SCIPgetNBinVars(), SCIPgetVarsData(), and TRUE.

◆ DECL_NHFREE() [2/2]

static DECL_NHFREE ( nhFreeDins )

static

deinitialization callback for DINS before SCIP is freed

Definition at line 3429 of file heur_alns.c.

References Nh::data, DECL_NHREFSOL, Nh::dins, NULL, SCIP_OKAY, and SCIPfreeBlockMemory.

◆ DECL_NHREFSOL() [2/2]

static DECL_NHREFSOL ( nhRefsolIncumbent )

static

callback that returns the incumbent solution as a reference point

Definition at line 3440 of file heur_alns.c.

References DECL_NHDEACTIVATE, NULL, SCIP_DIDNOTFIND, SCIP_OKAY, SCIP_SUCCESS, and SCIPgetBestSol().

◆ DECL_NHDEACTIVATE() [1/3]

static DECL_NHDEACTIVATE ( nhDeactivateDiscreteVars )

static

callback function that deactivates a neighborhood on problems with no discrete variables

Definition at line 3460 of file heur_alns.c.

References DECL_NHDEACTIVATE, NULL, SCIP_OKAY, SCIPgetNBinVars(), and SCIPgetNIntVars().

◆ DECL_NHDEACTIVATE() [2/3]

static DECL_NHDEACTIVATE ( nhDeactivateBinVars )

static

callback function that deactivates a neighborhood on problems with no binary variables

Definition at line 3473 of file heur_alns.c.

References DECL_NHDEACTIVATE, NULL, SCIP_OKAY, and SCIPgetNBinVars().

◆ DECL_NHDEACTIVATE() [3/3]

static DECL_NHDEACTIVATE ( nhDeactivateObjVars )

static

callback function that deactivates a neighborhood on problems with no objective variables

Definition at line 3486 of file heur_alns.c.

References includeNeighborhoods(), NULL, SCIP_OKAY, and SCIPgetNObjVars().

◆ includeNeighborhoods()

static SCIP_RETCODE includeNeighborhoods	(	SCIP *	scip,
		SCIP_HEURDATA *	heurdata
	)

static

include all neighborhoods

Parameters

scip	SCIP data structure
heurdata	heuristic data of the ALNS heuristic

Definition at line 3500 of file heur_alns.c.

Referenced by DECL_NHDEACTIVATE(), and SCIPincludeHeurAlns().

◆ SCIP_DECL_HEURINIT()

static SCIP_DECL_HEURINIT ( heurInitAlns )

static

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

Definition at line 3578 of file heur_alns.c.

References DEFAULT_REWARDFILENAME, Nh::fixingrate, neighborhoodInit(), neighborhoodStatsReset(), NULL, resetFixingRate(), SCIP_CALL, SCIP_DECL_HEURINITSOL(), SCIP_FILECREATEERROR, SCIP_OKAY, SCIPdebugMsg, SCIPerrorMessage, SCIPheurGetData(), and Nh::stats.

Referenced by includeNeighborhoods().

◆ SCIP_DECL_HEURINITSOL()

static SCIP_DECL_HEURINITSOL ( heurInitsolAlns )

static

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

Definition at line 3626 of file heur_alns.c.

References Nh::active, createBandit(), NULL, resetCurrentNeighborhood(), resetMinimumImprovement(), resetTargetNodeLimit(), SCIP_Bool, SCIP_CALL, SCIP_DECL_HEUREXIT(), SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPbanditGetNActions(), SCIPfreeBandit(), SCIPfreeBufferArray, SCIPgetNVars(), SCIPheurGetData(), SCIPresetBandit(), and SCIPswapPointers().

Referenced by SCIP_DECL_HEURINIT().

◆ SCIP_DECL_HEUREXIT()

static SCIP_DECL_HEUREXIT ( heurExitAlns )

static

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

Definition at line 3706 of file heur_alns.c.

References neighborhoodExit(), NULL, SCIP_CALL, SCIP_DECL_HEURFREE(), SCIP_OKAY, and SCIPheurGetData().

Referenced by SCIP_DECL_HEURINITSOL().

◆ SCIP_DECL_HEURFREE()

static SCIP_DECL_HEURFREE ( heurFreeAlns )

static

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

Definition at line 3736 of file heur_alns.c.

References alnsFreeNeighborhood(), NNEIGHBORHOODS, NULL, SCIP_CALL, SCIP_DECL_TABLEOUTPUT(), SCIP_OKAY, SCIPfreeBandit(), SCIPfreeBlockMemory, SCIPfreeBlockMemoryArray, and SCIPheurGetData().

Referenced by SCIP_DECL_HEUREXIT().

◆ SCIP_DECL_TABLEOUTPUT()

static SCIP_DECL_TABLEOUTPUT ( tableOutputNeighborhood )

static

output method of statistics table to output file stream 'file'

Definition at line 3768 of file heur_alns.c.

References HEUR_NAME, NULL, printNeighborhoodStatistics(), SCIP_OKAY, SCIPfindHeur(), SCIPheurGetData(), and SCIPincludeHeurAlns().

Referenced by SCIP_DECL_HEURFREE().

SCIP

Detailed Description

Data Structures

Macros

Typedefs

Enumerations

Functions

Macro Definition Documentation

◆ HEUR_NAME

◆ HEUR_DESC

◆ HEUR_DISPCHAR

◆ HEUR_PRIORITY

◆ HEUR_FREQ

◆ HEUR_FREQOFS

◆ HEUR_MAXDEPTH

◆ HEUR_TIMING

◆ HEUR_USESSUBSCIP

◆ NNEIGHBORHOODS

◆ DEFAULT_NODESQUOT

◆ DEFAULT_NODESOFFSET

◆ DEFAULT_NSOLSLIM

◆ DEFAULT_MINNODES

◆ DEFAULT_MAXNODES

◆ DEFAULT_WAITINGNODES

◆ DEFAULT_TARGETNODEFACTOR

◆ LRATEMIN

◆ LPLIMFAC

◆ DEFAULT_MINIMPROVELOW

◆ DEFAULT_MINIMPROVEHIGH

◆ MINIMPROVEFAC

◆ DEFAULT_STARTMINIMPROVE

◆ DEFAULT_ADJUSTMINIMPROVE

◆ DEFAULT_ADJUSTTARGETNODES

◆ DEFAULT_BESTSOLWEIGHT

◆ DEFAULT_BANDITALGO

◆ DEFAULT_REWARDCONTROL

◆ DEFAULT_SCALEBYEFFORT

◆ DEFAULT_RESETWEIGHTS

◆ DEFAULT_SUBSCIPRANDSEEDS

◆ DEFAULT_REWARDBASELINE

◆ DEFAULT_FIXTOL

◆ DEFAULT_UNFIXTOL

◆ DEFAULT_USELOCALREDCOST

◆ DEFAULT_BETA

◆ DEFAULT_EPS

◆ DEFAULT_ALPHA

◆ DEFAULT_GAMMA

◆ DEFAULT_USEREDCOST

◆ DEFAULT_USEPSCOST

◆ DEFAULT_USEDISTANCES

◆ DEFAULT_DOMOREFIXINGS

◆ DEFAULT_ADJUSTFIXINGRATE

◆ FIXINGRATE_DECAY

◆ FIXINGRATE_STARTINC

◆ DEFAULT_USESUBSCIPHEURS

◆ DEFAULT_COPYCUTS

◆ DEFAULT_REWARDFILENAME

◆ DEFAULT_SEED

◆ MUTATIONSEED

◆ CROSSOVERSEED

◆ DEFAULT_MINFIXINGRATE_RENS

◆ DEFAULT_MAXFIXINGRATE_RENS

◆ DEFAULT_ACTIVE_RENS

◆ DEFAULT_PRIORITY_RENS

◆ DEFAULT_MINFIXINGRATE_RINS

◆ DEFAULT_MAXFIXINGRATE_RINS

◆ DEFAULT_ACTIVE_RINS

◆ DEFAULT_PRIORITY_RINS

◆ DEFAULT_MINFIXINGRATE_MUTATION

◆ DEFAULT_MAXFIXINGRATE_MUTATION

◆ DEFAULT_ACTIVE_MUTATION

◆ DEFAULT_PRIORITY_MUTATION

◆ DEFAULT_MINFIXINGRATE_LOCALBRANCHING

◆ DEFAULT_MAXFIXINGRATE_LOCALBRANCHING

◆ DEFAULT_ACTIVE_LOCALBRANCHING

◆ DEFAULT_PRIORITY_LOCALBRANCHING

◆ DEFAULT_MINFIXINGRATE_PROXIMITY

◆ DEFAULT_MAXFIXINGRATE_PROXIMITY

◆ DEFAULT_ACTIVE_PROXIMITY

◆ DEFAULT_PRIORITY_PROXIMITY