Scippy

SCIP

Solving Constraint Integer Programs

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Detailed Description

fixing roundable variables to best bound

Author: Tobias Achterberg; Stefan Heinz

Definition in file prop_dualfix.c.

#include <assert.h>
#include <string.h>
#include "scip/prop_dualfix.h"

Go to the source code of this file.

Macros
#define	PROP_NAME "dualfix"

#define	PROP_DESC "roundable variables dual fixing"

#define	PROP_TIMING SCIP_PROPTIMING_BEFORELP

#define	PROP_PRIORITY +8000000

#define	PROP_FREQ 0

#define	PROP_DELAY FALSE

#define	PROP_PRESOL_PRIORITY +8000000

#define	PROP_PRESOL_MAXROUNDS -1

#define	PROP_PRESOL_DELAY FALSE

Functions
Local methods
static SCIP_RETCODE	performDualfix (SCIP scip, int nfixedvars, SCIP_Bool unbounded, SCIP_Bool cutoff)

Callback methods
static	SCIP_DECL_PROPCOPY (propCopyDualfix)

static	SCIP_DECL_PROPPRESOL (propPresolDualfix)

static	SCIP_DECL_PROPEXEC (propExecDualfix)

Interface methods
SCIP_RETCODE	SCIPincludePropDualfix (SCIP *scip)

Macro Definition Documentation

#define PROP_NAME "dualfix"

Definition at line 30 of file prop_dualfix.c.

Referenced by SCIP_DECL_PROPCOPY(), SCIP_DECL_PROPEXEC(), SCIP_DECL_PROPPRESOL(), and SCIPincludePropDualfix().

#define PROP_DESC "roundable variables dual fixing"

Definition at line 31 of file prop_dualfix.c.

Referenced by SCIPincludePropDualfix().

#define PROP_TIMING SCIP_PROPTIMING_BEFORELP

Definition at line 32 of file prop_dualfix.c.

Referenced by SCIPincludePropDualfix().

#define PROP_PRIORITY +8000000

propagation priority

Definition at line 33 of file prop_dualfix.c.

Referenced by SCIPincludePropDualfix().

#define PROP_FREQ 0

propagation frequency

Definition at line 34 of file prop_dualfix.c.

Referenced by SCIPincludePropDualfix().

#define PROP_DELAY FALSE

should propagation method be delayed, if other propagators found reductions?

Definition at line 35 of file prop_dualfix.c.

Referenced by SCIPincludePropDualfix().

#define PROP_PRESOL_PRIORITY +8000000

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

Definition at line 37 of file prop_dualfix.c.

Referenced by SCIPincludePropDualfix().

#define PROP_PRESOL_MAXROUNDS -1

maximal number of propving rounds the propver participates in (-1: no limit)

Definition at line 38 of file prop_dualfix.c.

Referenced by SCIPincludePropDualfix().

#define PROP_PRESOL_DELAY FALSE

should propver be delayed, if other propvers found reductions?

Definition at line 39 of file prop_dualfix.c.

Referenced by SCIPincludePropDualfix().

Function Documentation

static SCIP_RETCODE performDualfix	(	SCIP *	scip,
		int *	nfixedvars,
		SCIP_Bool *	unbounded,
		SCIP_Bool *	cutoff
	)

static

perform dual presolving

Parameters

scip	SCIP data structure
nfixedvars	pointer to store number of fixed variables
unbounded	pointer to store if an unboundness was detected
cutoff	pointer to store if a cutoff was detected

Definition at line 49 of file prop_dualfix.c.

References NULL, REALABS, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIP_STAGE_PRESOLVING, SCIP_STAGE_SOLVING, SCIP_VERBLEVEL_NORMAL, SCIPceil(), SCIPdebugMessage, SCIPfixVar(), SCIPfloor(), SCIPgetNVars(), SCIPgetStage(), SCIPgetVars(), SCIPisFeasEQ(), SCIPisInfinity(), SCIPisLE(), SCIPisLT(), SCIPisNegative(), SCIPisPositive(), SCIPisZero(), SCIPvarGetLbGlobal(), SCIPvarGetLbLocal(), SCIPvarGetName(), SCIPvarGetNLocksDown(), SCIPvarGetNLocksUp(), SCIPvarGetObj(), SCIPvarGetUbGlobal(), SCIPvarGetUbLocal(), SCIPvarIsDeleted(), SCIPvarMayRoundDown(), SCIPvarMayRoundUp(), SCIPverbMessage(), and TRUE.

Referenced by SCIP_DECL_PROPEXEC(), and SCIP_DECL_PROPPRESOL().

static SCIP_DECL_PROPCOPY ( propCopyDualfix )

static

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

Definition at line 211 of file prop_dualfix.c.

References NULL, PROP_NAME, SCIP_CALL, SCIP_OKAY, SCIPincludePropDualfix(), and SCIPpropGetName().

static SCIP_DECL_PROPPRESOL ( propPresolDualfix )

static

presolving method of propagator

Definition at line 225 of file prop_dualfix.c.

References FALSE, NULL, performDualfix(), PROP_NAME, SCIP_Bool, SCIP_CALL, SCIP_CUTOFF, SCIP_DIDNOTFIND, SCIP_OKAY, SCIP_SUCCESS, SCIP_UNBOUNDED, and SCIPpropGetName().

static SCIP_DECL_PROPEXEC ( propExecDualfix )

static

execution method of propagator

Warning: Don't run in probing or in repropagation since this can lead to wrong conclusion

Definition at line 256 of file prop_dualfix.c.

References FALSE, NULL, performDualfix(), PROP_NAME, SCIP_Bool, SCIP_CALL, SCIP_CUTOFF, SCIP_DIDNOTFIND, SCIP_DIDNOTRUN, SCIP_OKAY, SCIP_REDUCEDDOM, SCIP_UNBOUNDED, SCIPinProbing(), SCIPinRepropagation(), and SCIPpropGetName().

SCIP_RETCODE SCIPincludePropDualfix ( SCIP * scip )

creates the dual fixing propagator and includes it in SCIP

Parameters

scip	SCIP data structure

Definition at line 300 of file prop_dualfix.c.

References NULL, PROP_DELAY, PROP_DESC, PROP_FREQ, PROP_NAME, PROP_PRESOL_DELAY, PROP_PRESOL_MAXROUNDS, PROP_PRESOL_PRIORITY, PROP_PRIORITY, PROP_TIMING, SCIP_CALL, SCIP_OKAY, SCIPincludePropBasic(), SCIPsetPropCopy(), and SCIPsetPropPresol().

Referenced by SCIP_DECL_PROPCOPY(), and SCIPincludeDefaultPlugins().