presol_dualinfer.c File Reference

Detailed Description

dual inference presolver

Author

Dieter Weninger

This presolver exploits dual information for primal variable fixings: a) The first method is an enhanced dual fixing technique. b) The second method does dual bound strengthening on continuous primal variables and applies complementary slackness (yA-c)_i > 0 => x_i = 0 for fixing primal variables at their lower bound.

Definition in file presol_dualinfer.c.

#include <stdio.h>
#include <assert.h>
#include <string.h>
#include "scip/cons_knapsack.h"
#include "scip/cons_linear.h"
#include "scip/cons_logicor.h"
#include "scip/cons_setppc.h"
#include "scip/cons_varbound.h"
#include "presol_dualinfer.h"

Go to the source code of this file.

Macros
#define	PRESOL_NAME   "dualinfer"
#define	PRESOL_DESC   "exploit dual informations for variable fixings"
#define	PRESOL_PRIORITY   20010000
#define	PRESOL_MAXROUNDS   0
#define	PRESOL_DELAY   TRUE
#define	MAX_LOOPS   7

Typedefs
typedef enum Fixingdirection	FIXINGDIRECTION
typedef struct ConstraintMatrix	CONSTRAINTMATRIX

Enumerations
enum	Fixingdirection {   FIXATLB = -1,   NOFIX = 0,   FIXATUB = 1,   FIXATLB = -1,   NOFIX = 0,   FIXATUB = 1 }

Functions
static SCIP_RETCODE	getActiveVariables (SCIP *scip, SCIP_VAR ***vars, SCIP_Real **scalars, int *nvars, SCIP_Real *constant)
static SCIP_RETCODE	addRow (SCIP *scip, CONSTRAINTMATRIX *matrix, SCIP_VAR **vars, SCIP_Real *vals, int nvars, SCIP_Real lhs, SCIP_Real rhs)
static SCIP_RETCODE	addConstraint (SCIP *scip, CONSTRAINTMATRIX *matrix, SCIP_VAR **vars, SCIP_Real *vals, int nvars, SCIP_Real lhs, SCIP_Real rhs)
static SCIP_RETCODE	setColumnMajorFormat (SCIP *scip, CONSTRAINTMATRIX *matrix)
static SCIP_RETCODE	calcActivityBounds (SCIP *scip, CONSTRAINTMATRIX *matrix)
static SCIP_RETCODE	initMatrix (SCIP *scip, CONSTRAINTMATRIX **matrixptr, SCIP_Bool *initialized)
static void	freeMatrix (SCIP *scip, CONSTRAINTMATRIX **matrix)
static SCIP_Bool	isRowRedundant (SCIP *scip, CONSTRAINTMATRIX *matrix, int row)
static void	initShadowPrices (SCIP *scip, CONSTRAINTMATRIX *matrix, SCIP_Real *lowershadow, SCIP_Real *uppershadow)
static SCIP_RETCODE	singletonColumns (SCIP *scip, CONSTRAINTMATRIX *matrix, SCIP_Real *lowershadow, SCIP_Real *uppershadow, int *nfitsinglecols)
static void	costCalculation (SCIP *scip, CONSTRAINTMATRIX *matrix, SCIP_Real *lowershadow, SCIP_Real *uppershadow, SCIP_Real *lowercosts, SCIP_Real *uppercosts)
static void	fixColumns (SCIP *scip, CONSTRAINTMATRIX *matrix, SCIP_Real *lowercosts, SCIP_Real *uppercosts, int *npossiblefixings, FIXINGDIRECTION *varstofix)
static SCIP_RETCODE	costFixing (SCIP *scip, CONSTRAINTMATRIX *matrix, FIXINGDIRECTION *varstofix, int *nfitsinglecols, int *npossiblefixings)
static SCIP_Real	getMaxColActWithoutRow (SCIP *scip, CONSTRAINTMATRIX *matrix, int col, int withoutrow, SCIP_Real *lbdual, SCIP_Real *ubdual)
static SCIP_Real	getMinColActWithoutRow (SCIP *scip, CONSTRAINTMATRIX *matrix, int col, int withoutrow, SCIP_Real *lbdual, SCIP_Real *ubdual)
static void	calcColActivityResiduals (SCIP *scip, CONSTRAINTMATRIX *matrix, int col, int row, SCIP_Real val, SCIP_Real *lbdual, SCIP_Real *ubdual, SCIP_Real *mincolact, SCIP_Real *maxcolact, int *maxcolactinf, int *mincolactinf, SCIP_Real *mincolresact, SCIP_Real *maxcolresact)
static void	calcColActivity (SCIP *scip, CONSTRAINTMATRIX *matrix, SCIP_Real *lbdual, SCIP_Real *ubdual, int startcol, int stopcol, SCIP_Bool *excludevar, SCIP_Real *mincolact, SCIP_Real *maxcolact, int *maxcolactinf, int *mincolactinf)
static void	updateDualBounds (SCIP *scip, CONSTRAINTMATRIX *matrix, SCIP_Real objval, SCIP_Real val, int row, SCIP_Real mincolresact, SCIP_Real *lbdual, SCIP_Real *ubdual, int *boundchanges, SCIP_Bool *updateinfcnt)
static void	infCounterUpdate (SCIP *scip, CONSTRAINTMATRIX *matrix, SCIP_Real val, int row, SCIP_Real *lbdual, SCIP_Real *ubdual, SCIP_Bool *excludevar, SCIP_Real *mincolact, SCIP_Real *maxcolact, int *maxcolactinf, int *mincolactinf)
static SCIP_RETCODE	dualBoundStrengthening (SCIP *scip, CONSTRAINTMATRIX *matrix, FIXINGDIRECTION *varstofix, int *nfitsinglecols, int *npossiblefixings)
static	SCIP_DECL_PRESOLCOPY (presolCopyDualinfer)
static	SCIP_DECL_PRESOLEXEC (presolExecDualinfer)
SCIP_RETCODE	SCIPincludePresolDualinfer (SCIP *scip)

Macro Definition Documentation

#define PRESOL_NAME   "dualinfer"

Definition at line 44 of file presol_dualinfer.c.

Referenced by SCIP_DECL_PRESOLCOPY(), and SCIPincludePresolDualinfer().

#define PRESOL_DESC   "exploit dual informations for variable fixings"

Definition at line 45 of file presol_dualinfer.c.

Referenced by SCIPincludePresolDualinfer().

#define PRESOL_PRIORITY   20010000

priority of the presolver (>= 0: before, < 0: after constraint handlers)

Definition at line 46 of file presol_dualinfer.c.

Referenced by SCIPincludePresolDualinfer().

#define PRESOL_MAXROUNDS   0

maximal number of presolving rounds the presolver participates in (-1: no limit)

Definition at line 47 of file presol_dualinfer.c.

Referenced by SCIPincludePresolDualinfer().

#define PRESOL_DELAY   TRUE

should presolver be delayed, if other presolvers found reductions?

Definition at line 48 of file presol_dualinfer.c.

Referenced by SCIPincludePresolDualinfer().

#define MAX_LOOPS   7

maximal number of dual bound strengthening loops

Definition at line 50 of file presol_dualinfer.c.

Referenced by dualBoundStrengthening().

Typedef Documentation

typedef enum Fixingdirection FIXINGDIRECTION

Definition at line 65 of file presol_dualinfer.c.

typedef struct ConstraintMatrix CONSTRAINTMATRIX

Definition at line 102 of file presol_dualinfer.c.

Enumeration Type Documentation

enum Fixingdirection

type of fixing direction

Enumerator:

FIXATLB	fix variable at lower bound
NOFIX	do not fix variable
FIXATUB	fix variable at upper bound
FIXATLB
NOFIX
FIXATUB

Definition at line 59 of file presol_dualinfer.c.

Function Documentation

static SCIP_RETCODE getActiveVariables ( SCIP *  scip, SCIP_VAR ***  vars, SCIP_Real **  scalars, int *  nvars, SCIP_Real *  constant  )

static

transforms given variables, scalars, and constant to the corresponding active variables, scalars, and constant

Parameters

scip	SCIP data structure
vars	vars array to get active variables for
scalars	scalars a_1, ..., a_n in linear sum a_1*x_1 + ... + a_n*x_n + c
nvars	pointer to number of variables and values in vars and vals array
constant	pointer to constant c in linear sum a_1*x_1 + ... + a_n*x_n + c

Definition at line 106 of file presol_dualinfer.c.

References NULL, SCIP_CALL, SCIP_OKAY, SCIPgetProbvarLinearSum(), SCIPreallocBufferArray, and TRUE.

Referenced by addConstraint().

static SCIP_RETCODE addRow ( SCIP *  scip, CONSTRAINTMATRIX *  matrix, SCIP_VAR **  vars, SCIP_Real *  vals, int  nvars, SCIP_Real  lhs, SCIP_Real  rhs  )

static

add one row to the constraint matrix

Parameters

scip	SCIP data structure
matrix	constraint matrix
vars	variables of this row
vals	coefficients of this row
nvars	number of variables of this row
lhs	left hand side
rhs	right hand side

Definition at line 141 of file presol_dualinfer.c.

References NULL, SCIP_OKAY, SCIP_Real, SCIPinfinity(), SCIPisInfinity(), SCIPvarGetProbindex(), and TRUE.

Referenced by addConstraint().

static SCIP_RETCODE addConstraint ( SCIP *  scip, CONSTRAINTMATRIX *  matrix, SCIP_VAR **  vars, SCIP_Real *  vals, int  nvars, SCIP_Real  lhs, SCIP_Real  rhs  )

static

add one constraint to matrix

Parameters

scip	current scip instance
matrix	constraint matrix
vars	variables of this constraint
vals	variable coefficients of this constraint
nvars	number of variables
lhs	left hand side
rhs	right hand side

Definition at line 207 of file presol_dualinfer.c.

References addRow(), getActiveVariables(), NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPduplicateBufferArray, SCIPfreeBufferArray, SCIPisInfinity(), and SCIPisLE().

Referenced by initMatrix().

static SCIP_RETCODE setColumnMajorFormat ( SCIP *  scip, CONSTRAINTMATRIX *  matrix  )

static

transform row major format into column major format

Parameters

scip	current scip instance
matrix	constraint matrix

Definition at line 286 of file presol_dualinfer.c.

References BMSclearMemoryArray, NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, and SCIPfreeBufferArray.

Referenced by initMatrix().

static SCIP_RETCODE calcActivityBounds ( SCIP *  scip, CONSTRAINTMATRIX *  matrix  )

static

calculate min/max activity per row

Parameters

scip	current scip instance
matrix	constraint matrix

Definition at line 353 of file presol_dualinfer.c.

References NULL, SCIP_OKAY, SCIP_Real, SCIPinfinity(), and SCIPisInfinity().

Referenced by initMatrix().

static SCIP_RETCODE initMatrix ( SCIP *  scip, CONSTRAINTMATRIX **  matrixptr, SCIP_Bool *  initialized  )

static

initialize matrix

Parameters

scip	current scip instance
matrixptr	pointer to constraint matrix object to be initialized
initialized	was the initialization successful?

Definition at line 431 of file presol_dualinfer.c.

References addConstraint(), calcActivityBounds(), FALSE, NULL, SCIP_Bool, SCIP_CALL, SCIP_ERROR, SCIP_Longint, SCIP_OKAY, SCIP_Real, SCIP_SETPPCTYPE_COVERING, SCIP_SETPPCTYPE_PACKING, SCIP_SETPPCTYPE_PARTITIONING, SCIPallocBuffer, SCIPallocBufferArray, SCIPallocClearMemoryArray, SCIPconsGetName(), SCIPconshdlrGetCheckConss(), SCIPconshdlrGetName(), SCIPconshdlrGetNCheckConss(), SCIPconsIsTransformed(), SCIPdebugMessage, SCIPduplicateBufferArray, SCIPfreeBufferArray, SCIPgetCapacityKnapsack(), SCIPgetConshdlrs(), SCIPgetLhsLinear(), SCIPgetLhsVarbound(), SCIPgetNConshdlrs(), SCIPgetNConss(), SCIPgetNVars(), SCIPgetNVarsKnapsack(), SCIPgetNVarsLinear(), SCIPgetNVarsLogicor(), SCIPgetNVarsSetppc(), SCIPgetRhsLinear(), SCIPgetRhsVarbound(), SCIPgetTypeSetppc(), SCIPgetValsLinear(), SCIPgetVars(), SCIPgetVarsKnapsack(), SCIPgetVarsLinear(), SCIPgetVarsLogicor(), SCIPgetVarsSetppc(), SCIPgetVarVarbound(), SCIPgetVbdcoefVarbound(), SCIPgetVbdvarVarbound(), SCIPgetWeightsKnapsack(), SCIPinfinity(), SCIPisStopped(), SCIPreallocBufferArray, SCIPvarGetLbGlobal(), SCIPvarGetNLocksDown(), SCIPvarGetNLocksUp(), SCIPvarGetUbGlobal(), setColumnMajorFormat(), and TRUE.

Referenced by SCIP_DECL_PRESOLEXEC().

static void freeMatrix ( SCIP *  scip, CONSTRAINTMATRIX **  matrix  )

static

frees the constraint matrix

Parameters

scip	current SCIP instance
matrix	constraint matrix object

Definition at line 754 of file presol_dualinfer.c.

References NULL, SCIPfreeBuffer, SCIPfreeBufferArray, SCIPfreeBufferArrayNull, and SCIPfreeMemoryArray.

Referenced by SCIP_DECL_PRESOLEXEC().

static SCIP_Bool isRowRedundant ( SCIP *  scip, CONSTRAINTMATRIX *  matrix, int  row  )

static

return if row is redundant or not

Parameters

scip	SCIP main data structure
matrix	matrix containing the constraints
row	row to be checked for redundancy

Definition at line 829 of file presol_dualinfer.c.

References NULL, and SCIPisFeasLE().

Referenced by costCalculation().

static void initShadowPrices ( SCIP *  scip, CONSTRAINTMATRIX *  matrix, SCIP_Real *  lowershadow, SCIP_Real *  uppershadow  )

static

initialize shadow prices

Parameters

scip	SCIP main data structure
matrix	matrix containing the constraints
lowershadow	lower shadow prices
uppershadow	upper shadow prices

Definition at line 845 of file presol_dualinfer.c.

References NULL, and SCIPinfinity().

Referenced by costFixing().

static SCIP_RETCODE singletonColumns ( SCIP *  scip, CONSTRAINTMATRIX *  matrix, SCIP_Real *  lowershadow, SCIP_Real *  uppershadow, int *  nfitsinglecols  )

static

search for singleton columns and update shadow prices

Parameters

scip	SCIP main data structure
matrix	matrix containing the constraints
lowershadow	lower shadows
uppershadow	upper shadows
nfitsinglecols	number of fitting singleton columns

Definition at line 868 of file presol_dualinfer.c.

References NULL, SCIP_OKAY, SCIP_Real, SCIP_VARTYPE_CONTINUOUS, SCIPisInfinity(), SCIPvarGetObj(), SCIPvarGetType(), and SCIPvarGetUbGlobal().

Referenced by costFixing().

static void costCalculation ( SCIP *  scip, CONSTRAINTMATRIX *  matrix, SCIP_Real *  lowershadow, SCIP_Real *  uppershadow, SCIP_Real *  lowercosts, SCIP_Real *  uppercosts  )

static

calculate min/max costs per column

Parameters

scip	SCIP main data structure
matrix	matrix containing the constraints
lowershadow	lower shadows
uppershadow	upper shadows
lowercosts	lower shadow costs
uppercosts	upper shadow costs

Definition at line 925 of file presol_dualinfer.c.

References FALSE, isRowRedundant(), NULL, SCIP_Bool, SCIP_Real, SCIPinfinity(), and SCIPisInfinity().

Referenced by costFixing().

static void fixColumns ( SCIP *  scip, CONSTRAINTMATRIX *  matrix, SCIP_Real *  lowercosts, SCIP_Real *  uppercosts, int *  npossiblefixings, FIXINGDIRECTION *  varstofix  )

static

fix variables at their bounds out of the min/max costs

Parameters

scip	SCIP main data structure
matrix	matrix containing the constraints
lowercosts	lower shadow costs
uppercosts	upper shadow costs
npossiblefixings	number of possible fixings
varstofix	array holding information for later upper/lower bound fixing

Definition at line 1008 of file presol_dualinfer.c.

References FIXATLB, FIXATUB, NULL, SCIP_Real, SCIPisInfinity(), SCIPvarGetLbGlobal(), SCIPvarGetObj(), and SCIPvarGetUbGlobal().

Referenced by costFixing().

static SCIP_RETCODE costFixing ( SCIP *  scip, CONSTRAINTMATRIX *  matrix, FIXINGDIRECTION *  varstofix, int *  nfitsinglecols, int *  npossiblefixings  )

static

dual cost fixing

Parameters

scip	SCIP main data structure
matrix	matrix containing the constraints
varstofix	array holding information for later upper/lower bound fixing
nfitsinglecols	number of continuous singleton columns
npossiblefixings	number of possible fixings

Definition at line 1059 of file presol_dualinfer.c.

References costCalculation(), fixColumns(), initShadowPrices(), NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPfreeBufferArray, and singletonColumns().

Referenced by SCIP_DECL_PRESOLEXEC().

static SCIP_Real getMaxColActWithoutRow ( SCIP *  scip, CONSTRAINTMATRIX *  matrix, int  col, int  withoutrow, SCIP_Real *  lbdual, SCIP_Real *  ubdual  )

static

calculate maximal column activity from one continuous variable without one row

Parameters

scip	SCIP main data structure
matrix	matrix containing the constraints
col	column index
withoutrow	exclude row index
lbdual	lower bounds of dual variables
ubdual	upper bounds of dual variables

Definition at line 1101 of file presol_dualinfer.c.

References NULL, SCIP_Real, SCIP_VARTYPE_CONTINUOUS, SCIPisInfinity(), and SCIPvarGetType().

Referenced by calcColActivityResiduals().

static SCIP_Real getMinColActWithoutRow ( SCIP *  scip, CONSTRAINTMATRIX *  matrix, int  col, int  withoutrow, SCIP_Real *  lbdual, SCIP_Real *  ubdual  )

static

calculate minimal column activity from one continuous variable without one row

Parameters

scip	SCIP main data structure
matrix	matrix containing the constraints
col	column index
withoutrow	exclude row index
lbdual	lower bounds of dual variables
ubdual	upper bounds of dual variables

Definition at line 1157 of file presol_dualinfer.c.

References NULL, SCIP_Real, SCIP_VARTYPE_CONTINUOUS, SCIPisInfinity(), and SCIPvarGetType().

Referenced by calcColActivityResiduals().

static void calcColActivityResiduals ( SCIP *  scip, CONSTRAINTMATRIX *  matrix, int  col, int  row, SCIP_Real  val, SCIP_Real *  lbdual, SCIP_Real *  ubdual, SCIP_Real *  mincolact, SCIP_Real *  maxcolact, int *  maxcolactinf, int *  mincolactinf, SCIP_Real *  mincolresact, SCIP_Real *  maxcolresact  )

static

calculate minimal/maximal column residual activities

Parameters

scip	SCIP main data structure
matrix	matrix containing the constraints
col	column index
row	row index
val	matrix coefficient
lbdual	lower bounds of dual variables
ubdual	upper bounds of dual variables
mincolact	minimal column activities
maxcolact	maximal column activities
maxcolactinf	number of (positive) infinite contributions to maximal column activity
mincolactinf	number of (negative) infinite contributions to minimal column activity
mincolresact	minimal column residual activity
maxcolresact	maximal column residual activity

Definition at line 1213 of file presol_dualinfer.c.

References getMaxColActWithoutRow(), getMinColActWithoutRow(), NULL, SCIP_VARTYPE_CONTINUOUS, SCIPinfinity(), SCIPisInfinity(), and SCIPvarGetType().

Referenced by dualBoundStrengthening().

static void calcColActivity ( SCIP *  scip, CONSTRAINTMATRIX *  matrix, SCIP_Real *  lbdual, SCIP_Real *  ubdual, int  startcol, int  stopcol, SCIP_Bool *  excludevar, SCIP_Real *  mincolact, SCIP_Real *  maxcolact, int *  maxcolactinf, int *  mincolactinf  )

static

calculate minimal/maximal column activity on continuous variables

Parameters

scip	SCIP main data structure
matrix	matrix containing the constraints
lbdual	lower bounds of dual variables
ubdual	upper bounds of dual variables
startcol	start column index
stopcol	stop column index
excludevar	indicating if variable is within an equation or ranged row
mincolact	minimal column activities
maxcolact	maximal column activities
maxcolactinf	number of (positive) inifite contributions to maximal column activity
mincolactinf	number of (negative) infinite contributions to minimal column activity

Definition at line 1316 of file presol_dualinfer.c.

References FALSE, NULL, SCIP_Real, SCIP_VARTYPE_CONTINUOUS, SCIPinfinity(), SCIPisInfinity(), SCIPisPositive(), SCIPvarGetLbGlobal(), SCIPvarGetType(), SCIPvarGetUbGlobal(), and TRUE.

Referenced by dualBoundStrengthening(), and infCounterUpdate().

static void updateDualBounds ( SCIP *  scip, CONSTRAINTMATRIX *  matrix, SCIP_Real  objval, SCIP_Real  val, int  row, SCIP_Real  mincolresact, SCIP_Real *  lbdual, SCIP_Real *  ubdual, int *  boundchanges, SCIP_Bool *  updateinfcnt  )

static

update bounds on dual variables

Parameters

scip	SCIP main data structure
matrix	matrix containing the constraints
objval	objective function value
val	matrix coefficient
row	row index
mincolresact	minimal column residual activity
lbdual	dual lower bounds
ubdual	dual upper bounds
boundchanges	number of bound changes
updateinfcnt	flag indicating to update infinity counters

Definition at line 1427 of file presol_dualinfer.c.

References FALSE, NULL, SCIP_Real, SCIPisInfinity(), and TRUE.

Referenced by dualBoundStrengthening().

static void infCounterUpdate ( SCIP *  scip, CONSTRAINTMATRIX *  matrix, SCIP_Real  val, int  row, SCIP_Real *  lbdual, SCIP_Real *  ubdual, SCIP_Bool *  excludevar, SCIP_Real *  mincolact, SCIP_Real *  maxcolact, int *  maxcolactinf, int *  mincolactinf  )

static

update minimal/maximal column activity infinity counters

Parameters

scip	SCIP main data structure
matrix	matrix containing the constraints
val	matrix coefficient
row	row index
lbdual	lower bounds of dual variables
ubdual	upper bounds of dual variables
excludevar	indicating if variable is within an equation or ranged row
mincolact	minimal column activities
maxcolact	maximal column activities
maxcolactinf	number of (positive) infinity contributions to maximal column activity
mincolactinf	number of (negative) infinity contributions to minimal column activity

Definition at line 1491 of file presol_dualinfer.c.

References calcColActivity(), NULL, SCIP_Real, SCIP_VARTYPE_CONTINUOUS, and SCIPvarGetType().

Referenced by dualBoundStrengthening().

static SCIP_RETCODE dualBoundStrengthening ( SCIP *  scip, CONSTRAINTMATRIX *  matrix, FIXINGDIRECTION *  varstofix, int *  nfitsinglecols, int *  npossiblefixings  )

static

dual bound strengthening on continuous variables

Parameters

scip	SCIP main data structure
matrix	matrix containing the constraints
varstofix	array holding information for later upper/lower bound fixing
nfitsinglecols	number of continuous singleton columns
npossiblefixings	found number of possible fixings

Definition at line 1601 of file presol_dualinfer.c.

References calcColActivity(), calcColActivityResiduals(), FALSE, FIXATLB, infCounterUpdate(), MAX_LOOPS, NOFIX, NULL, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIP_VARTYPE_CONTINUOUS, SCIPallocBufferArray, SCIPfreeBufferArray, SCIPinfinity(), SCIPisInfinity(), SCIPisLT(), SCIPisNegative(), SCIPvarGetLbGlobal(), SCIPvarGetObj(), SCIPvarGetType(), SCIPvarGetUbGlobal(), TRUE, and updateDualBounds().

Referenced by SCIP_DECL_PRESOLEXEC().

static SCIP_DECL_PRESOLCOPY ( presolCopyDualinfer  )

static

copy method for constraint handler plugins (called when SCIP copies plugins)

Definition at line 1811 of file presol_dualinfer.c.

References NULL, PRESOL_NAME, SCIP_CALL, SCIP_OKAY, SCIPincludePresolDualinfer(), and SCIPpresolGetName().

static SCIP_DECL_PRESOLEXEC ( presolExecDualinfer  )

static

execution method of presolver

Definition at line 1825 of file presol_dualinfer.c.

References BMSclearMemoryArray, costFixing(), dualBoundStrengthening(), FALSE, FIXATLB, FIXATUB, freeMatrix(), initMatrix(), NULL, SCIP_Bool, SCIP_CALL, SCIP_CUTOFF, SCIP_DIDNOTFIND, SCIP_DIDNOTRUN, SCIP_OKAY, SCIP_Real, SCIP_STAGE_PRESOLVING, SCIP_SUCCESS, SCIP_VARTYPE_BINARY, SCIP_VARTYPE_CONTINUOUS, SCIPallocBufferArray, SCIPdebugMessage, SCIPfixVar(), SCIPfreeBufferArray, SCIPgetNContVars(), SCIPgetStage(), SCIPinProbing(), SCIPisFeasIntegral(), SCIPvarGetLbLocal(), SCIPvarGetType(), and SCIPvarGetUbLocal().

SCIP_RETCODE SCIPincludePresolDualinfer

(

SCIP *

scip

)

creates the dual inference presolver and includes it in SCIP

Parameters

scip	SCIP data structure

Definition at line 1959 of file presol_dualinfer.c.

References NULL, PRESOL_DELAY, PRESOL_DESC, PRESOL_MAXROUNDS, PRESOL_NAME, PRESOL_PRIORITY, SCIP_CALL, SCIP_OKAY, SCIPincludePresolBasic(), and SCIPsetPresolCopy().

Referenced by SCIP_DECL_PRESOLCOPY(), and SCIPincludeDefaultPlugins().