ABA_VARIABLE Class Reference

class forms the virtual base class for all possible variables given in pool format More...

#include <variable.h>

Inheritance diagram for ABA_VARIABLE:


Public Member Functions
	ABA_VARIABLE (ABA_MASTER master, const ABA_SUB sub, bool dynamic, bool local, double obj, double lBound, double uBound, ABA_VARTYPE::TYPE type)
virtual	~ABA_VARIABLE ()
	The destructor.
ABA_VARTYPE::TYPE	varType () const
bool	discrete ()
bool	binary ()
bool	integer ()
virtual double	obj ()
double	uBound () const
void	uBound (double newValue)
	This version of the function uBound() sets the upper bound of the variable.
double	lBound () const
void	lBound (double newValue)
	This version of the function lBound() sets the lower bound of the variable.
ABA_FSVARSTAT *	fsVarStat ()
virtual bool	valid (ABA_SUB *sub)
virtual int	genColumn (ABA_ACTIVE< ABA_CONSTRAINT, ABA_VARIABLE > *actCon, ABA_COLUMN &col)
	Computes the column col of the variable associated with the active constraints *actCon.
virtual double	coeff (ABA_CONSTRAINT *con)
virtual bool	violated (double rc) const
	Checks, if a variable does not price out correctly, i.e., if the reduced cost rc is positive for a maximization problem and negative for a minimization problem, respectively.
virtual bool	violated (ABA_ACTIVE< ABA_CONSTRAINT, ABA_VARIABLE > constraints, double y, double *slack=0)
	This version of the function violated() checks if the variable does not price out correctly, i.e., if the reduced cost of the variable associated with the constraint set constraints and the dual variables y are positive for a maximization problem and negative for a minimization problem, respectively.
virtual double	redCost (ABA_ACTIVE< ABA_CONSTRAINT, ABA_VARIABLE > actCon, double y)
	Computes the reduced cost of the variable corresponding the constraint set actCon and the dual variables y.
virtual bool	useful (ABA_ACTIVE< ABA_CONSTRAINT, ABA_VARIABLE > actCon, double y, double lpVal)
	An (inactive) discrete variable is considered as useful() if its activation might not produce only solutions worse than the best known feasible solution.
void	printCol (ostream &out, ABA_ACTIVE< ABA_CONSTRAINT, ABA_VARIABLE > *constraints)
	Writes the column of the variable corresponding to the constraints on the stream out.
Protected Attributes
ABA_FSVARSTAT	fsVarStat_
double	obj_
double	lBound_
double	uBound_
ABA_VARTYPE	type_

Detailed Description

class forms the virtual base class for all possible variables given in pool format

Definition at line 55 of file variable.h.

Constructor & Destructor Documentation

ABA_VARIABLE::ABA_VARIABLE	(	ABA_MASTER *	master,
		const ABA_SUB *	sub,
		bool	dynamic,
		bool	local,
		double	obj,
		double	lBound,
		double	uBound,
		ABA_VARTYPE::TYPE	type
	)

The constructor.

Parameters:

	master	A pointer to the corresponding master of the optimization.
	sub	A pointer to the subproblem associated with the variable. This can also be the 0-pointer.
	dynamic	If this argument is true, then the variable can also be removed again from the set of active variables after it is added once.
	local	If this argument is true, then the variable is only locally valid, otherwise it is globally valid. As a locally valid variable is always associated with a subproblem, the argument sub must not be 0 if local is true.
	obj	The objective function coefficient.
	lBound	The lower bound of the variable.
	uBound	The upper bound of the variable.
	type	The type of the variable.

virtual ABA_VARIABLE::~ABA_VARIABLE ( ) [virtual]

The destructor.

Member Function Documentation

ABA_VARTYPE::TYPE ABA_VARIABLE::varType ( ) const [inline]

Returns:: The type of the variable.

Definition at line 302 of file variable.h.

bool ABA_VARIABLE::discrete ( ) [inline]

Returns:: true If the type of the variable is Integer or Binary,
false otherwise.

Definition at line 307 of file variable.h.

bool ABA_VARIABLE::binary ( ) [inline]

Returns:: true If the type of the variable is Binary,
false otherwise.

Definition at line 312 of file variable.h.

bool ABA_VARIABLE::integer ( ) [inline]

Returns:: true If the type of the variable is Integer,
false otherwise.

Definition at line 317 of file variable.h.

virtual double ABA_VARIABLE::obj ( ) [virtual]

Returns:: The objective function coefficient.

double ABA_VARIABLE::uBound ( ) const [inline]

Returns:: The upper bound of the variable.

Definition at line 332 of file variable.h.

void ABA_VARIABLE::uBound ( double newValue ) [inline]

This version of the function uBound() sets the upper bound of the variable.

Parameters:

newBound

The new value of the upper bound.

Definition at line 337 of file variable.h.

double ABA_VARIABLE::lBound ( ) const [inline]

Returns:: The lower bound of the variable.

Definition at line 322 of file variable.h.

void ABA_VARIABLE::lBound ( double newValue ) [inline]

This version of the function lBound() sets the lower bound of the variable.

Parameters:

newBound

The new value of the lower bound.

Definition at line 327 of file variable.h.

ABA_FSVARSTAT * ABA_VARIABLE::fsVarStat ( ) [inline]

Returns:: A pointer to the global status of fixing and setting of the variable.

Note:: This is the global status of fixing/setting that might differ from the local status of fixing/setting a variable returned by the function ABA_SUB::fsVarStat().

Definition at line 342 of file variable.h.

virtual bool ABA_VARIABLE::valid ( ABA_SUB * sub ) [virtual]

Returns:: true If the variable is globally valid, or the subproblem sub is an ancestor in the enumeration tree of the subproblem associated with the variable,
false otherwise.

Parameters:

sub

The subproblem for which validity of the variable is checked.

virtual int ABA_VARIABLE::genColumn	(	ABA_ACTIVE< ABA_CONSTRAINT, ABA_VARIABLE > *	actCon,
		ABA_COLUMN &	col
	)			`[virtual]`

Computes the column col of the variable associated with the active constraints *actCon.

Note:: The upper and lower bound of the column are initialized with the global upper and lower bound of the variable. Therefore, an adaption with the local bounds might be required.

Returns:: The number of nonzero entries in col.

Parameters:

	actCon	The constraints for which the column of the variable should be computed.
	col	Stores the column when the function terminates.

virtual double ABA_VARIABLE::coeff ( ABA_CONSTRAINT * con ) [virtual]

Computes the coefficient of the variable in the constraint con.

Per default the coefficient of a variable is computed indirectly via the coefficient of a constraint. Problem specific redefinitions might be required.

Returns:: The coefficient of the variable in the constraint con.

Parameters:

con

The constraint of which the coefficient should be computed.

Reimplemented in ABA_COLVAR.

virtual bool ABA_VARIABLE::violated ( double rc ) const [virtual]

Checks, if a variable does not price out correctly, i.e., if the reduced cost rc is positive for a maximization problem and negative for a minimization problem, respectively.

Returns:: true If the variable does not price out correctly.
false otherwise.

Parameters:

The reduced cost of the variable.

virtual bool ABA_VARIABLE::violated	(	ABA_ACTIVE< ABA_CONSTRAINT, ABA_VARIABLE > *	constraints,
		double *	y,
		double *	slack = `0`
	)			`[virtual]`

This version of the function violated() checks if the variable does not price out correctly, i.e., if the reduced cost of the variable associated with the constraint set constraints and the dual variables y are positive for a maximization problem and negative for a minimization problem, respectively.

Returns:: true If the variable does not price out correctly.
false otherwise.

Parameters:

	constraints	The constraints associated with the dual variables y.
	y	The dual variables of the constraint.
	r	If r is not the 0-pointer, it will store the reduced cost after the function call. Per default r is 0.

virtual double ABA_VARIABLE::redCost	(	ABA_ACTIVE< ABA_CONSTRAINT, ABA_VARIABLE > *	actCon,
		double *	y
	)			`[virtual]`

Computes the reduced cost of the variable corresponding the constraint set actCon and the dual variables y.

Given the dual variables $y$ , then the reduced cost of a variable with objective function coefficient $c_e$ , column $a_{.e}$ are defined as $c_e - y^{\mathrm{T}} a_{.e}$ .

Returns:: The reduced cost of the variable.

Parameters:

	actCon	The constraints associated with the dual variables y.
	y	The dual variables of the constraint.

virtual bool ABA_VARIABLE::useful	(	ABA_ACTIVE< ABA_CONSTRAINT, ABA_VARIABLE > *	actCon,
		double *	y,
		double	lpVal
	)			`[virtual]`

An (inactive) discrete variable is considered as useful() if its activation might not produce only solutions worse than the best known feasible solution.

This is the same criterion for fixing inactive variables by reduced cost criteria.

Returns:: true If the variable is considered as useful,
false otherwise.

Parameters:

	actCon	The active constraints.
	y	The dual variables of these constraints.
	lpVal	The value of the linear program.

void ABA_VARIABLE::printCol	(	ostream &	out,
		ABA_ACTIVE< ABA_CONSTRAINT, ABA_VARIABLE > *	constraints
	)

Writes the column of the variable corresponding to the constraints on the stream out.

Parameters:

	out	The output stream.
	constraints	The constraints for which the column should be written.

Member Data Documentation

ABA_FSVARSTAT ABA_VARIABLE::fsVarStat_ [protected]

The global status of fixing and setting of the variable.

Definition at line 282 of file variable.h.

double ABA_VARIABLE::obj_ [protected]

The objective function coefficient of the variable.

Definition at line 286 of file variable.h.

double ABA_VARIABLE::lBound_ [protected]

The lower bound of the variable.

Definition at line 290 of file variable.h.

double ABA_VARIABLE::uBound_ [protected]

The upper bound of the variable.

Definition at line 294 of file variable.h.

ABA_VARTYPE ABA_VARIABLE::type_ [protected]

The type of the variable.

Definition at line 298 of file variable.h.

The documentation for this class was generated from the following file:

Include/abacus/variable.h

Generated on Tue Aug 14 18:10:00 2007 for ABACUS by

1.5.1

ABA_VARIABLE Class Reference

Public Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation