presol_stuffing.c File Reference

Detailed Description

fix singleton continuous variables

Author

Dieter Weninger

Investigate singleton continuous variables if one can be fixed at a bound.

Definition in file presol_stuffing.c.

#include <stdio.h>
#include <assert.h>
#include <string.h>
#include "scip/pub_matrix.h"
#include "presol_stuffing.h"

Go to the source code of this file.

Macros
#define	PRESOL_NAME   "stuffing"
#define	PRESOL_DESC   "fix redundant singleton continuous variables"
#define	PRESOL_PRIORITY   -100
#define	PRESOL_MAXROUNDS   -1
#define	PRESOL_TIMING   SCIP_PRESOLTIMING_EXHAUSTIVE /* timing of the presolver (fast, medium, or exhaustive) */

Typedefs
typedef enum Fixingdirection	FIXINGDIRECTION

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

Functions
static SCIP_RETCODE	singletonColumnStuffing (SCIP *scip, SCIP_MATRIX *matrix, FIXINGDIRECTION *varstofix, int *nfixings)
static	SCIP_DECL_PRESOLCOPY (presolCopyStuffing)
static	SCIP_DECL_PRESOLEXEC (presolExecStuffing)
SCIP_RETCODE	SCIPincludePresolStuffing (SCIP *scip)

Macro Definition Documentation

#define PRESOL_NAME   "stuffing"

Definition at line 36 of file presol_stuffing.c.

Referenced by SCIP_DECL_PRESOLCOPY(), and SCIPincludePresolStuffing().

#define PRESOL_DESC   "fix redundant singleton continuous variables"

Definition at line 37 of file presol_stuffing.c.

Referenced by SCIPincludePresolStuffing().

#define PRESOL_PRIORITY   -100

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

Definition at line 38 of file presol_stuffing.c.

Referenced by SCIPincludePresolStuffing().

#define PRESOL_MAXROUNDS   -1

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

Definition at line 39 of file presol_stuffing.c.

Referenced by SCIPincludePresolStuffing().

#define PRESOL_TIMING   SCIP_PRESOLTIMING_EXHAUSTIVE /* timing of the presolver (fast, medium, or exhaustive) */

Definition at line 40 of file presol_stuffing.c.

Referenced by SCIPincludePresolStuffing().

Typedef Documentation

typedef enum Fixingdirection FIXINGDIRECTION

Definition at line 49 of file presol_stuffing.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
FIXATLB	fix variable at lower bound
NOFIX	do not fix variable
FIXATUB	fix variable at upper bound

Definition at line 43 of file presol_stuffing.c.

Function Documentation

static SCIP_RETCODE singletonColumnStuffing ( SCIP *  scip, SCIP_MATRIX *  matrix, FIXINGDIRECTION *  varstofix, int *  nfixings  )

static

try to fix singleton continuous variables

Parameters

scip	SCIP main data structure
matrix	matrix containing the constraints
varstofix	array holding fixing information
nfixings	number of possible fixings

Definition at line 57 of file presol_stuffing.c.

References BMSclearMemoryArray, FALSE, FIXATLB, FIXATUB, NULL, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIP_VARTYPE_CONTINUOUS, SCIPallocBufferArray, SCIPfreeBufferArray, SCIPisGE(), SCIPisGT(), SCIPisInfinity(), SCIPisLE(), SCIPisLT(), SCIPmatrixGetColIdxPtr(), SCIPmatrixGetColNDownlocks(), SCIPmatrixGetColNNonzs(), SCIPmatrixGetColNUplocks(), SCIPmatrixGetNColumns(), SCIPmatrixGetNRows(), SCIPmatrixGetRowIdxPtr(), SCIPmatrixGetRowLhs(), SCIPmatrixGetRowNNonzs(), SCIPmatrixGetRowValPtr(), SCIPmatrixGetVar(), SCIPmatrixIsRowRhsInfinity(), SCIPsortRealRealIntInt(), SCIPvarGetLbGlobal(), SCIPvarGetNLocksDown(), SCIPvarGetNLocksUp(), SCIPvarGetObj(), SCIPvarGetType(), SCIPvarGetUbGlobal(), and TRUE.

Referenced by SCIP_DECL_PRESOLEXEC().

static SCIP_DECL_PRESOLCOPY ( presolCopyStuffing  )

static

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

Definition at line 325 of file presol_stuffing.c.

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

static SCIP_DECL_PRESOLEXEC ( presolExecStuffing  )

static

execution method of presolver

Definition at line 339 of file presol_stuffing.c.

References BMSclearMemoryArray, FIXATLB, FIXATUB, NULL, SCIP_Bool, SCIP_CALL, SCIP_CUTOFF, SCIP_DIDNOTFIND, SCIP_DIDNOTRUN, SCIP_OKAY, SCIP_Real, SCIP_STAGE_PRESOLVING, SCIP_SUCCESS, SCIP_VARTYPE_CONTINUOUS, SCIPallocBufferArray, SCIPallowDualReds(), SCIPdebugMessage, SCIPfixVar(), SCIPfreeBufferArray, SCIPgetNActivePricers(), SCIPgetNContVars(), SCIPgetStage(), SCIPinProbing(), SCIPisInfinity(), SCIPisNLPEnabled(), SCIPisStopped(), SCIPmatrixCreate(), SCIPmatrixFree(), SCIPmatrixGetColNDownlocks(), SCIPmatrixGetColNUplocks(), SCIPmatrixGetNColumns(), SCIPmatrixGetVar(), SCIPvarGetLbGlobal(), SCIPvarGetName(), SCIPvarGetNLocksDown(), SCIPvarGetNLocksUp(), SCIPvarGetType(), SCIPvarGetUbGlobal(), and singletonColumnStuffing().

SCIP_RETCODE SCIPincludePresolStuffing

(

SCIP *

scip

)

creates the stuffing presolver and includes it in SCIP

Parameters

scip	SCIP data structure

Definition at line 466 of file presol_stuffing.c.

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

Referenced by SCIP_DECL_PRESOLCOPY(), and SCIPincludeDefaultPlugins().