Detailed Description

flow cover and complemented mixed integer rounding cuts separator (Marchand's version)

Author: Leona Gottwald; Kati Wolter; Tobias Achterberg

For an overview see:

Marchand, H., & Wolsey, L. A. (2001).
Aggregation and mixed integer rounding to solve MIPs.
Operations research, 49(3), 363-371.

Some remarks:

In general, continuous variables are less prefered than integer variables, since their cut coefficient is worse.
We seek for aggregations that project out continuous variables that are far away from their bound, since if it is at its bound then it doesn't contribute to the violation
These aggregations are also useful for the flowcover separation, so after building an aggregation we try to generate a MIR cut and a flowcover cut.
We only keep the best cut.

Definition in file sepa_aggregation.c.

#include "blockmemshell/memory.h"
#include "scip/cuts.h"
#include "scip/pub_lp.h"
#include "scip/pub_message.h"
#include "scip/pub_misc.h"
#include "scip/pub_misc_sort.h"
#include "scip/pub_sepa.h"
#include "scip/pub_var.h"
#include "scip/scip_branch.h"
#include "scip/scip_cut.h"
#include "scip/scip_general.h"
#include "scip/scip_lp.h"
#include "scip/scip_mem.h"
#include "scip/scip_message.h"
#include "scip/scip_numerics.h"
#include "scip/scip_param.h"
#include "scip/scip_prob.h"
#include "scip/scip_sepa.h"
#include "scip/scip_sol.h"
#include "scip/scip_solvingstats.h"
#include "scip/scip_tree.h"
#include "scip/scip_var.h"
#include "scip/sepa_aggregation.h"
#include <string.h>

Go to the source code of this file.

Data Structures
struct	AggregationData

Macros
#define	SEPA_NAME "aggregation"

#define	SEPA_DESC "aggregation heuristic for complemented mixed integer rounding cuts and flowcover cuts"

#define	SEPA_PRIORITY -3000

#define	SEPA_FREQ 10

#define	SEPA_MAXBOUNDDIST 1.0

#define	SEPA_USESSUBSCIP FALSE

#define	SEPA_DELAY FALSE

#define	DEFAULT_MAXROUNDS -1

#define	DEFAULT_MAXROUNDSROOT -1

#define	DEFAULT_MAXTRIES 200

#define	DEFAULT_MAXTRIESROOT -1

#define	DEFAULT_MAXFAILS 20

#define	DEFAULT_MAXFAILSROOT 100

#define	DEFAULT_MAXAGGRS 3

#define	DEFAULT_MAXAGGRSROOT 6

#define	DEFAULT_MAXSEPACUTS 100

#define	DEFAULT_MAXSEPACUTSROOT 500

#define	DEFAULT_MAXSLACK 0.0

#define	DEFAULT_MAXSLACKROOT 0.1

#define	DEFAULT_DENSITYSCORE 1e-4

#define	DEFAULT_SLACKSCORE 1e-3

#define	DEFAULT_MAXAGGDENSITY 0.20

#define	DEFAULT_MAXROWDENSITY 0.05

#define	DEFAULT_DENSITYOFFSET 100

#define	DEFAULT_MAXROWFAC 1e+4

#define	DEFAULT_MAXTESTDELTA -1

#define	DEFAULT_AGGRTOL 1e-2

#define	DEFAULT_TRYNEGSCALING TRUE

#define	DEFAULT_FIXINTEGRALRHS TRUE

#define	DEFAULT_DYNAMICCUTS TRUE

#define	BOUNDSWITCH 0.5

#define	POSTPROCESS TRUE

#define	USEVBDS TRUE

#define	MINFRAC 0.05

#define	MAXFRAC 0.999

#define	MAKECONTINTEGRAL FALSE

#define	IMPLINTSARECONT

Typedefs
typedef struct AggregationData	AGGREGATIONDATA

Functions
static SCIP_RETCODE	addCut (SCIP scip, SCIP_SOL sol, SCIP_SEPA sepa, SCIP_Bool makeintegral, SCIP_Real cutcoefs, int cutinds, int cutnnz, SCIP_Real cutrhs, SCIP_Real cutefficacy, SCIP_Bool cutislocal, SCIP_Bool cutremovable, int cutrank, const char cutclassname, SCIP_Bool cutoff, int ncuts, SCIP_ROW **thecut)

static SCIP_RETCODE	setupAggregationData (SCIP scip, SCIP_SOL sol, SCIP_Bool allowlocal, AGGREGATIONDATA *aggrdata)

static void	destroyAggregationData (SCIP scip, AGGREGATIONDATA aggrdata)

static SCIP_Bool	getRowAggregationCandidates (AGGREGATIONDATA aggrdata, int probvaridx, SCIP_ROW rows, SCIP_Real rowvarcoefs, int nrows, int ngoodrows)

static SCIP_Real	aggrdataGetBoundDist (AGGREGATIONDATA *aggrdata, int probvaridx)

static SCIP_RETCODE	aggregateNextRow (SCIP scip, SCIP_SEPADATA sepadata, SCIP_Real rowlhsscores, SCIP_Real rowrhsscores, AGGREGATIONDATA aggrdata, SCIP_AGGRROW aggrrow, int naggrs, SCIP_Bool success)

static SCIP_RETCODE	aggregation (SCIP scip, AGGREGATIONDATA aggrdata, SCIP_SEPA sepa, SCIP_SOL sol, SCIP_Bool allowlocal, SCIP_Real rowlhsscores, SCIP_Real rowrhsscores, int startrow, int maxaggrs, SCIP_Bool wastried, SCIP_Bool cutoff, int cutinds, SCIP_Real cutcoefs, SCIP_Bool negate, int *ncuts)

static SCIP_Real	getRowFracActivity (SCIP_ROW row, SCIP_Real fractionalities)

static SCIP_RETCODE	separateCuts (SCIP scip, SCIP_SEPA sepa, SCIP_SOL sol, SCIP_Bool allowlocal, int depth, SCIP_RESULT result)

static	SCIP_DECL_SEPACOPY (sepaCopyAggregation)

static	SCIP_DECL_SEPAFREE (sepaFreeAggregation)

static	SCIP_DECL_SEPAEXECLP (sepaExeclpAggregation)

static	SCIP_DECL_SEPAEXECSOL (sepaExecsolAggregation)

static	SCIP_DECL_SEPAEXECLP (sepaExeclpDummy)

static	SCIP_DECL_SEPAEXECSOL (sepaExecsolDummy)

SCIP_RETCODE	SCIPincludeSepaAggregation (SCIP *scip)

Macro Definition Documentation

◆ SEPA_NAME

#define SEPA_NAME "aggregation"

Definition at line 76 of file sepa_aggregation.c.

Referenced by separateCuts().

◆ SEPA_DESC

#define SEPA_DESC "aggregation heuristic for complemented mixed integer rounding cuts and flowcover cuts"

Definition at line 77 of file sepa_aggregation.c.

◆ SEPA_PRIORITY

#define SEPA_PRIORITY -3000

Definition at line 78 of file sepa_aggregation.c.

◆ SEPA_FREQ

#define SEPA_FREQ 10

Definition at line 79 of file sepa_aggregation.c.

◆ SEPA_MAXBOUNDDIST

#define SEPA_MAXBOUNDDIST 1.0

Definition at line 80 of file sepa_aggregation.c.

◆ SEPA_USESSUBSCIP

#define SEPA_USESSUBSCIP FALSE

does the separator use a secondary SCIP instance?

Definition at line 81 of file sepa_aggregation.c.

◆ SEPA_DELAY

#define SEPA_DELAY FALSE

should separation method be delayed, if other separators found cuts?

Definition at line 82 of file sepa_aggregation.c.

◆ DEFAULT_MAXROUNDS

#define DEFAULT_MAXROUNDS -1

maximal number of cmir separation rounds per node (-1: unlimited)

Definition at line 84 of file sepa_aggregation.c.

◆ DEFAULT_MAXROUNDSROOT

#define DEFAULT_MAXROUNDSROOT -1

maximal number of cmir separation rounds in the root node (-1: unlimited)

Definition at line 85 of file sepa_aggregation.c.

◆ DEFAULT_MAXTRIES

#define DEFAULT_MAXTRIES 200

maximal number of rows to start aggregation with per separation round (-1: unlimited)

Definition at line 86 of file sepa_aggregation.c.

◆ DEFAULT_MAXTRIESROOT

#define DEFAULT_MAXTRIESROOT -1

maximal number of rows to start aggregation with per round in the root node (-1: unlimited)

Definition at line 89 of file sepa_aggregation.c.

◆ DEFAULT_MAXFAILS

#define DEFAULT_MAXFAILS 20

maximal number of consecutive unsuccessful aggregation tries (-1: unlimited)

Definition at line 92 of file sepa_aggregation.c.

◆ DEFAULT_MAXFAILSROOT

#define DEFAULT_MAXFAILSROOT 100

maximal number of consecutive unsuccessful aggregation tries in the root node (-1: unlimited)

Definition at line 93 of file sepa_aggregation.c.

◆ DEFAULT_MAXAGGRS

#define DEFAULT_MAXAGGRS 3

maximal number of aggregations for each row per separation round

Definition at line 96 of file sepa_aggregation.c.

◆ DEFAULT_MAXAGGRSROOT

#define DEFAULT_MAXAGGRSROOT 6

maximal number of aggregations for each row per round in the root node

Definition at line 97 of file sepa_aggregation.c.

◆ DEFAULT_MAXSEPACUTS

#define DEFAULT_MAXSEPACUTS 100

maximal number of cmir cuts separated per separation round

Definition at line 98 of file sepa_aggregation.c.

◆ DEFAULT_MAXSEPACUTSROOT

#define DEFAULT_MAXSEPACUTSROOT 500

maximal number of cmir cuts separated per separation round in root node

Definition at line 99 of file sepa_aggregation.c.

◆ DEFAULT_MAXSLACK

#define DEFAULT_MAXSLACK 0.0

maximal slack of rows to be used in aggregation

Definition at line 100 of file sepa_aggregation.c.

◆ DEFAULT_MAXSLACKROOT

#define DEFAULT_MAXSLACKROOT 0.1

maximal slack of rows to be used in aggregation in the root node

Definition at line 101 of file sepa_aggregation.c.

◆ DEFAULT_DENSITYSCORE

#define DEFAULT_DENSITYSCORE 1e-4

weight of row density in the aggregation scoring of the rows

Definition at line 102 of file sepa_aggregation.c.

◆ DEFAULT_SLACKSCORE

#define DEFAULT_SLACKSCORE 1e-3

weight of slack in the aggregation scoring of the rows

Definition at line 103 of file sepa_aggregation.c.

◆ DEFAULT_MAXAGGDENSITY

#define DEFAULT_MAXAGGDENSITY 0.20

maximal density of aggregated row

Definition at line 104 of file sepa_aggregation.c.

◆ DEFAULT_MAXROWDENSITY

#define DEFAULT_MAXROWDENSITY 0.05

maximal density of row to be used in aggregation

Definition at line 105 of file sepa_aggregation.c.

◆ DEFAULT_DENSITYOFFSET

#define DEFAULT_DENSITYOFFSET 100

additional number of variables allowed in row on top of density

Definition at line 106 of file sepa_aggregation.c.

◆ DEFAULT_MAXROWFAC

#define DEFAULT_MAXROWFAC 1e+4

maximal row aggregation factor

Definition at line 107 of file sepa_aggregation.c.

◆ DEFAULT_MAXTESTDELTA

#define DEFAULT_MAXTESTDELTA -1

maximal number of different deltas to try (-1: unlimited)

Definition at line 108 of file sepa_aggregation.c.

◆ DEFAULT_AGGRTOL

#define DEFAULT_AGGRTOL 1e-2

aggregation heuristic: we try to delete continuous variables from the current aggregation, whose distance to its tightest bound is >= L - DEFAULT_AGGRTOL, where L is the largest of the distances between a continuous variable's value and its tightest bound in the current aggregation

Definition at line 109 of file sepa_aggregation.c.

◆ DEFAULT_TRYNEGSCALING

#define DEFAULT_TRYNEGSCALING TRUE

should negative values also be tested in scaling?

Definition at line 116 of file sepa_aggregation.c.

◆ DEFAULT_FIXINTEGRALRHS

#define DEFAULT_FIXINTEGRALRHS TRUE

should an additional variable be complemented if f0 = 0?

Definition at line 117 of file sepa_aggregation.c.

◆ DEFAULT_DYNAMICCUTS

#define DEFAULT_DYNAMICCUTS TRUE

should generated cuts be removed from the LP if they are no longer tight?

Definition at line 118 of file sepa_aggregation.c.

◆ BOUNDSWITCH

#define BOUNDSWITCH 0.5

Definition at line 120 of file sepa_aggregation.c.

Referenced by aggregation().

◆ POSTPROCESS

#define POSTPROCESS TRUE

Definition at line 121 of file sepa_aggregation.c.

Referenced by aggregation().

◆ USEVBDS

#define USEVBDS TRUE

Definition at line 122 of file sepa_aggregation.c.

Referenced by aggregation().

◆ MINFRAC

#define MINFRAC 0.05

Definition at line 123 of file sepa_aggregation.c.

Referenced by aggregation().

◆ MAXFRAC

#define MAXFRAC 0.999

Definition at line 124 of file sepa_aggregation.c.

Referenced by aggregation().

◆ MAKECONTINTEGRAL

#define MAKECONTINTEGRAL FALSE

Definition at line 125 of file sepa_aggregation.c.

Referenced by addCut().

◆ IMPLINTSARECONT

#define IMPLINTSARECONT

Definition at line 126 of file sepa_aggregation.c.

Typedef Documentation

◆ AGGREGATIONDATA

typedef struct AggregationData AGGREGATIONDATA

data used for aggregation of row

Function Documentation

◆ addCut()

static SCIP_RETCODE addCut	(	SCIP *	scip,
		SCIP_SOL *	sol,
		SCIP_SEPA *	sepa,
		SCIP_Bool	makeintegral,
		SCIP_Real *	cutcoefs,
		int *	cutinds,
		int	cutnnz,
		SCIP_Real	cutrhs,
		SCIP_Real	cutefficacy,
		SCIP_Bool	cutislocal,
		SCIP_Bool	cutremovable,
		int	cutrank,
		const char *	cutclassname,
		SCIP_Bool *	cutoff,
		int *	ncuts,
		SCIP_ROW **	thecut
	)

static

adds given cut to LP if violated

Parameters

scip	SCIP data structure
sol	the solution that should be separated, or NULL for LP solution
sepa	separator
makeintegral	should cut be scaled to integral coefficients if possible?
cutcoefs	coefficients of active variables in cut
cutinds	problem indices of variables in cut
cutnnz	number of non-zeros in cut
cutrhs	right hand side of cut
cutefficacy	efficacy of cut
cutislocal	is the cut only locally valid?
cutremovable	should the cut be removed from the LP due to aging or cleanup?
cutrank	rank of the cut
cutclassname	name of cut class to use for row names
cutoff	whether a cutoff has been detected
ncuts	pointer to count the number of added cuts
thecut	pointer to return cut if it was added

Definition at line 195 of file sepa_aggregation.c.

References FALSE, MAKECONTINTEGRAL, NULL, SCIP_Bool, SCIP_CALL, SCIP_LONGINT_FORMAT, SCIP_MAXSTRLEN, SCIP_OKAY, SCIPaddPoolCut(), SCIPaddRow(), SCIPaddVarToRow(), SCIPcacheRowExtensions(), SCIPcreateEmptyRowSepa(), SCIPdebug, SCIPdebugMsg, SCIPepsilon(), SCIPflushRowExtensions(), SCIPgetNLPs(), SCIPgetRowMaxCoef(), SCIPgetRowMinCoef(), SCIPgetRowNumIntCols(), SCIPgetVars(), SCIPinfinity(), SCIPisCutEfficacious(), SCIPisCutNew(), SCIPisEfficacious(), SCIPisInfinity(), SCIPmakeRowIntegral(), SCIPprintRow(), SCIPreleaseRow(), SCIProwChgRank(), SCIProwGetNNonz(), SCIProwGetRank(), SCIProwGetRhs(), SCIPsnprintf(), SCIPsumepsilon(), and setupAggregationData().

Referenced by aggregation().

◆ setupAggregationData()

static SCIP_RETCODE setupAggregationData	(	SCIP *	scip,
		SCIP_SOL *	sol,
		SCIP_Bool	allowlocal,
		AGGREGATIONDATA *	aggrdata
	)

static

setup data for aggregating rows

Parameters

scip	SCIP data structure
sol	solution to separate, NULL for LP solution
allowlocal	should local cuts be allowed
aggrdata	pointer to aggregation data to setup

Definition at line 318 of file sepa_aggregation.c.

References AggregationData::aggrrow, AggregationData::aggrrows, AggregationData::aggrrowscoef, AggregationData::aggrrowssize, AggregationData::aggrrowsstart, BMSclearMemoryArray, AggregationData::bounddist, AggregationData::bounddistinds, destroyAggregationData(), MAX, MIN, AggregationData::naggrrows, AggregationData::nbadvarsinrow, AggregationData::nbounddistvars, AggregationData::ngoodaggrrows, NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPaggrRowCreate(), SCIPaggrRowFree(), SCIPallocBufferArray, SCIPcolGetNLPNonz(), SCIPcolGetRows(), SCIPcolGetVals(), SCIPgetLPRowsData(), SCIPgetSolVal(), SCIPgetVarClosestVlb(), SCIPgetVarClosestVub(), SCIPgetVarsData(), SCIPisEQ(), SCIPisZero(), SCIPreallocBufferArray, SCIProwGetLhs(), SCIProwGetLPPos(), SCIProwGetRhs(), SCIProwIsLocal(), SCIProwIsModifiable(), SCIPswapPointers(), SCIPswapReals(), SCIPvarGetCol(), SCIPvarGetLbGlobal(), SCIPvarGetLbLocal(), SCIPvarGetUbGlobal(), SCIPvarGetUbLocal(), and SCIPvarIsInLP().

Referenced by addCut(), and separateCuts().

◆ destroyAggregationData()

static void destroyAggregationData	(	SCIP *	scip,
		AGGREGATIONDATA *	aggrdata
	)

static

free resources held in aggregation data

Parameters

scip	SCIP datastructure
aggrdata	pointer to ggregation data

Definition at line 503 of file sepa_aggregation.c.

Referenced by separateCuts(), and setupAggregationData().

◆ getRowAggregationCandidates()

static SCIP_Bool getRowAggregationCandidates	(	AGGREGATIONDATA *	aggrdata,
		int	probvaridx,
		SCIP_ROW ***	rows,
		SCIP_Real **	rowvarcoefs,
		int *	nrows,
		int *	ngoodrows
	)

static

retrieves the candidate rows for canceling out the given variable, also returns the number of "good" rows which are the rows stored at the first ngoodrows positions. A row is good if its continuous variables are all at their bounds, except maybe the given continuous variable (in probvaridx)

Parameters

aggrdata	pointer to ggregation data
probvaridx	problem index of variables to retrieve candidates for
rows	pointer to store array to candidate rows
rowvarcoefs	pointer to store array of coefficients of given variable in the corresponding rows
nrows	pointer to return number of rows in returned arrays
ngoodrows	pointer to return number of "good" rows in the returned arrays

Definition at line 523 of file sepa_aggregation.c.

References aggrdataGetBoundDist(), AggregationData::aggrrows, AggregationData::aggrrowscoef, AggregationData::aggrrowsstart, AggregationData::bounddistinds, FALSE, AggregationData::nbounddistvars, AggregationData::ngoodaggrrows, SCIP_Real, SCIPsortedvecFindInt(), and TRUE.

Referenced by aggregateNextRow().

◆ aggrdataGetBoundDist()

static SCIP_Real aggrdataGetBoundDist	(	AGGREGATIONDATA *	aggrdata,
		int	probvaridx
	)

static

find the bound distance value in the aggregation data struct for the given variable problem index

Parameters

aggrdata	SCIP datastructure
probvaridx	problem index of variables to retrieve candidates for

Definition at line 547 of file sepa_aggregation.c.

Referenced by aggregateNextRow(), and getRowAggregationCandidates().

◆ aggregateNextRow()

static SCIP_RETCODE aggregateNextRow	(	SCIP *	scip,
		SCIP_SEPADATA *	sepadata,
		SCIP_Real *	rowlhsscores,
		SCIP_Real *	rowrhsscores,
		AGGREGATIONDATA *	aggrdata,
		SCIP_AGGRROW *	aggrrow,
		int *	naggrs,
		SCIP_Bool *	success
	)

static

Aggregates the next row suitable for cancelling out an active continuous variable.

Equality rows that contain no other active continuous variables are preffered and apart from that the scores for the rows are used to determine which row is aggregated next

Parameters

scip	SCIP data structure
sepadata	separator data
rowlhsscores	aggregation scores for left hand sides of row
rowrhsscores	aggregation scores for right hand sides of row
aggrdata	aggregation data
aggrrow	current aggregation row
naggrs	pointer to increase counter if real aggregation took place
success	pointer to return whether another row was added to the aggregation row

Definition at line 566 of file sepa_aggregation.c.

References aggrdataGetBoundDist(), aggregation(), FALSE, getRowAggregationCandidates(), MAX, MIN, AggregationData::nbadvarsinrow, NULL, REALABS, SCIP_Bool, SCIP_CALL, SCIP_ERROR, SCIP_OKAY, SCIP_Real, SCIPaggrRowAddRow(), SCIPaggrRowGetInds(), SCIPaggrRowGetNNz(), SCIPaggrRowGetProbvarValue(), SCIPaggrRowHasRowBeenAdded(), SCIPaggrRowRemoveZeros(), SCIPallocBufferArray, SCIPfreeBufferArray, SCIPgetNBinVars(), SCIPgetNContVars(), SCIPgetNImplVars(), SCIPgetNIntVars(), SCIPgetNVars(), SCIPisEQ(), SCIPisFeasZero(), SCIPisGT(), SCIPisInfinity(), SCIProwGetLhs(), SCIProwGetLPPos(), SCIProwGetRhs(), and SCIPsortDownRealInt().

Referenced by aggregation().

◆ aggregation()

static SCIP_RETCODE aggregation	(	SCIP *	scip,
		AGGREGATIONDATA *	aggrdata,
		SCIP_SEPA *	sepa,
		SCIP_SOL *	sol,
		SCIP_Bool	allowlocal,
		SCIP_Real *	rowlhsscores,
		SCIP_Real *	rowrhsscores,
		int	startrow,
		int	maxaggrs,
		SCIP_Bool *	wastried,
		SCIP_Bool *	cutoff,
		int *	cutinds,
		SCIP_Real *	cutcoefs,
		SCIP_Bool	negate,
		int *	ncuts
	)

static

aggregates different single mixed integer constraints by taking linear combinations of the rows of the LP

Parameters

scip	SCIP data structure
aggrdata	pointer to aggregation data
sepa	separator
sol	the solution that should be separated, or NULL for LP solution
allowlocal	should local cuts be allowed
rowlhsscores	aggregation scores for left hand sides of row
rowrhsscores	aggregation scores for right hand sides of row
startrow	index of row to start aggregation; -1 for using the objective cutoff constraint
maxaggrs	maximal number of aggregations
wastried	pointer to store whether the given startrow was actually tried
cutoff	whether a cutoff has been detected
cutinds	buffer array to store temporarily cut
cutcoefs	buffer array to store temporarily cut
negate	should the start row be multiplied by -1
ncuts	pointer to count the number of generated cuts

Definition at line 793 of file sepa_aggregation.c.

References addCut(), aggregateNextRow(), AggregationData::aggrrow, BOUNDSWITCH, FALSE, getRowFracActivity(), MAXFRAC, MINFRAC, NULL, POSTPROCESS, SCIP_Bool, SCIP_CALL, SCIP_INVALID, SCIP_OKAY, SCIP_Real, SCIPaggrRowAddObjectiveFunction(), SCIPaggrRowAddRow(), SCIPaggrRowClear(), SCIPaggrRowGetNNz(), SCIPaggrRowGetNRows(), SCIPaggrRowGetRowInds(), SCIPcalcFlowCover(), SCIPcalcKnapsackCover(), SCIPcutGenerationHeuristicCMIR(), SCIPdebugMsg, SCIPgetLPRowsData(), SCIPgetNLPCols(), SCIPgetRowSolActivity(), SCIPgetUpperbound(), SCIPinfinity(), SCIPisObjIntegral(), SCIPreleaseRow(), SCIProwGetLhs(), SCIProwGetName(), SCIProwGetParallelism(), SCIProwGetRhs(), SCIPsepaGetData(), TRUE, and USEVBDS.

Referenced by aggregateNextRow(), and separateCuts().

◆ getRowFracActivity()

static SCIP_Real getRowFracActivity	(	SCIP_ROW *	row,
		SCIP_Real *	fractionalities
	)

static

gives an estimate of how much the activity of this row is affected by fractionality in the current solution

Parameters

row	the LP row
fractionalities	array of fractionalities for each variable

Definition at line 1040 of file sepa_aggregation.c.

Referenced by aggregation(), and separateCuts().

◆ separateCuts()

static SCIP_RETCODE separateCuts	(	SCIP *	scip,
		SCIP_SEPA *	sepa,
		SCIP_SOL *	sol,
		SCIP_Bool	allowlocal,
		int	depth,
		SCIP_RESULT *	result
	)

static

searches for and adds c-MIR cuts that separate the given primal solution

Parameters

scip	SCIP data structure
sepa	the c-MIR separator
sol	the solution that should be separated, or NULL for LP solution
allowlocal	should local cuts be allowed
depth	current depth
result	pointer to store the result

Definition at line 1066 of file sepa_aggregation.c.

References aggregation(), destroyAggregationData(), FALSE, getRowFracActivity(), MAX, MIN, NULL, r, SCIP_Bool, SCIP_CALL, SCIP_CUTOFF, SCIP_DECL_SEPACOPY(), SCIP_DIDNOTFIND, SCIP_DIDNOTRUN, SCIP_OKAY, SCIP_Real, SCIP_SEPARATED, SCIPallocBufferArray, SCIPdebugMsg, SCIPfeasFrac(), SCIPfreeBufferArray, SCIPgetCutoffbound(), SCIPgetLPRowsData(), SCIPgetNContVars(), SCIPgetNImplVars(), SCIPgetNSepaRounds(), SCIPgetNVars(), SCIPgetObjNorm(), SCIPgetRowSolActivity(), SCIPgetSolVals(), SCIPgetVarClosestVlb(), SCIPgetVarClosestVub(), SCIPgetVars(), SCIPisEQ(), SCIPisInfinity(), SCIPisLE(), SCIPisPositive(), SCIPisStopped(), SCIProwGetDualsol(), SCIProwGetLhs(), SCIProwGetLPPos(), SCIProwGetName(), SCIProwGetNLPNonz(), SCIProwGetNorm(), SCIProwGetRhs(), SCIProwIsLocal(), SCIProwIsModifiable(), SCIPsepaGetData(), SCIPsepaGetFreq(), SCIPsepaGetName(), SCIPsepaGetNCallsAtNode(), SCIPsortDownRealInt(), SCIPvarGetProbindex(), SCIPvarGetVlbCoefs(), SCIPvarGetVlbVars(), SCIPvarGetVubCoefs(), SCIPvarGetVubVars(), SEPA_NAME, setupAggregationData(), and TRUE.

◆ SCIP_DECL_SEPACOPY()

static SCIP_DECL_SEPACOPY ( sepaCopyAggregation )

static

copy method for separator plugins (called when SCIP copies plugins)

Definition at line 1438 of file sepa_aggregation.c.

Referenced by separateCuts().

◆ SCIP_DECL_SEPAFREE()

static SCIP_DECL_SEPAFREE ( sepaFreeAggregation )

static

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

Definition at line 1452 of file sepa_aggregation.c.

◆ SCIP_DECL_SEPAEXECLP() [1/2]

static SCIP_DECL_SEPAEXECLP ( sepaExeclpAggregation )

static

LP solution separation method of separator

Definition at line 1469 of file sepa_aggregation.c.

◆ SCIP_DECL_SEPAEXECSOL() [1/2]

static SCIP_DECL_SEPAEXECSOL ( sepaExecsolAggregation )

static

arbitrary primal solution separation method of separator

Definition at line 1494 of file sepa_aggregation.c.

◆ SCIP_DECL_SEPAEXECLP() [2/2]

static SCIP_DECL_SEPAEXECLP ( sepaExeclpDummy )

static

LP solution separation method of dummy separator

Definition at line 1507 of file sepa_aggregation.c.

References NULL, and SCIP_DIDNOTRUN.

◆ SCIP_DECL_SEPAEXECSOL() [2/2]

static SCIP_DECL_SEPAEXECSOL ( sepaExecsolDummy )

static

arbitrary primal solution separation method of dummy separator

Definition at line 1518 of file sepa_aggregation.c.

SCIP

Detailed Description

Data Structures

Macros

Typedefs

Functions

Macro Definition Documentation

◆ SEPA_NAME

◆ SEPA_DESC

◆ SEPA_PRIORITY

◆ SEPA_FREQ

◆ SEPA_MAXBOUNDDIST

◆ SEPA_USESSUBSCIP

◆ SEPA_DELAY

◆ DEFAULT_MAXROUNDS

◆ DEFAULT_MAXROUNDSROOT

◆ DEFAULT_MAXTRIES

◆ DEFAULT_MAXTRIESROOT

◆ DEFAULT_MAXFAILS

◆ DEFAULT_MAXFAILSROOT

◆ DEFAULT_MAXAGGRS

◆ DEFAULT_MAXAGGRSROOT

◆ DEFAULT_MAXSEPACUTS

◆ DEFAULT_MAXSEPACUTSROOT

◆ DEFAULT_MAXSLACK

◆ DEFAULT_MAXSLACKROOT

◆ DEFAULT_DENSITYSCORE

◆ DEFAULT_SLACKSCORE

◆ DEFAULT_MAXAGGDENSITY

◆ DEFAULT_MAXROWDENSITY

◆ DEFAULT_DENSITYOFFSET

◆ DEFAULT_MAXROWFAC

◆ DEFAULT_MAXTESTDELTA

◆ DEFAULT_AGGRTOL

◆ DEFAULT_TRYNEGSCALING

◆ DEFAULT_FIXINTEGRALRHS

◆ DEFAULT_DYNAMICCUTS

◆ BOUNDSWITCH

◆ POSTPROCESS

◆ USEVBDS

◆ MINFRAC

◆ MAXFRAC

◆ MAKECONTINTEGRAL

◆ IMPLINTSARECONT

Typedef Documentation

◆ AGGREGATIONDATA

Function Documentation

◆ addCut()

◆ setupAggregationData()

◆ destroyAggregationData()

◆ getRowAggregationCandidates()

◆ aggrdataGetBoundDist()

◆ aggregateNextRow()

◆ aggregation()

◆ getRowFracActivity()

◆ separateCuts()

◆ SCIP_DECL_SEPACOPY()

◆ SCIP_DECL_SEPAFREE()

◆ SCIP_DECL_SEPAEXECLP() [1/2]

◆ SCIP_DECL_SEPAEXECSOL() [1/2]

◆ SCIP_DECL_SEPAEXECLP() [2/2]

◆ SCIP_DECL_SEPAEXECSOL() [2/2]