Implements constraints stored in the class Row. More...

#include <ogdf/lib/abacus/rowcon.h>

Inheritance diagram for abacus::RowCon:

Public Member Functions
	RowCon (Master master, const Sub sub, CSense::SENSE sense, int nnz, const Array< int > &support, const Array< double > &coeff, double rhs, bool dynamic, bool local, bool liftable)
	Creates a row constraint.

	RowCon (Master master, const Sub sub, CSense::SENSE sense, int nnz, int support, double coeff, double rhs, bool dynamic, bool local, bool liftable)
	Creates a row constraint.

virtual	~RowCon ()
	The destructor.

virtual double	coeff (const Variable *v) const override
	Computes the coefficient of a variable which must be of type NumVar.

virtual void	print (std::ostream &out) const override
	Writes the row format of the constraint on an output stream.

Row *	row ()
	Returns a pointer to the object of the class Row representing the constraint.

const Row *	row () const
	Returns a const pointer to the object of the class Row representing the constraint.

Public Member Functions inherited from abacus::Constraint
	Constraint (const Constraint &rhs)
	Copy constructor.

	Constraint (Master *master)
	Initializes an empty constraint.

	Constraint (Master master, const Sub sub, CSense::SENSE sense, double rhs, bool dynamic, bool local, bool liftable)
	Initializes a constraint.

virtual	~Constraint ()

ConClass *	classification (Active< Variable, Constraint > *var=nullptr) const
	Returns a pointer to the classification of the constraint.

virtual double	distance (double x, Active< Variable, Constraint > actVar) const
	Returns the Euclidean distance of x associated with variable set actVar to the hyperplane induced by the constraint.

virtual int	genRow (Active< Variable, Constraint > *var, Row &row) const
	Generates the row format of the constraint associated with the variable set var.

bool	liftable () const
	Checks if the constraint is liftable.

void	printRow (std::ostream &out, Active< Variable, Constraint > *var) const
	Writes the row format of the constraint associated with the variable set var to output stream out.

virtual double	rhs () const
	Returns the right hand side of the constraint.

CSense *	sense ()
	Returns a pointer to the sense of the constraint.

const CSense *	sense () const
	Returns a const pointer to the sense of the constraint.

virtual double	slack (Active< Variable, Constraint > variables, double x) const
	Computes the slack of the vector x associated with the variable set variables.

virtual bool	valid (Sub *sub) const
	Checks if the constraint is valid for the subproblem sub.

virtual bool	violated (Active< Variable, Constraint > variables, double x, double *sl=nullptr) const
	Checks if a constraint is violated by a vector x associated with a variable set.

virtual bool	violated (double slack) const
	Checks if a constraint is violated given the slack of a vector.

Public Member Functions inherited from abacus::ConVar
	ConVar (Master master, const Sub sub, bool dynamic, bool local)
	Creates an instance of type ConVar.

virtual	~ConVar ()

bool	active () const
	Checks if the constraint/variable is active in at least one active subproblem.

virtual bool	dynamic () const
	Return true if the constraint/variable is dynamic.

virtual bool	equal (const ConVar *cv) const
	Should compare if the constraint/variable is identical (in a mathematical sense) with the constraint/variable cv.

bool	global () const
	Returns true if the constraint/variable is globally valid, false otherwise.

virtual unsigned	hashKey () const
	Should provide a key for the constraint/variable that can be used to insert it into a hash table.

bool	local () const
	Returns true if the constraint/variable is only locally valid, false otherwise.

virtual const char *	name () const
	Should return the name of the constraint/variable.

virtual double	rank () const
	The function should return a rank associated with the constraint/variable.

const Sub *	sub () const
	Returns a const pointer to the subproblem associated with the constraint/variable.

void	sub (Sub *sub)
	Associates a new subproblem with the constraint/variable.

bool	expanded () const
	Returns true if the expanded format of a constraint/variable is available, false otherwise.

virtual void	expand () const
	Expands a constraint/variable.

virtual void	compress () const
	Compresses a constraint/variable.

virtual bool	deletable () const
	Returns true if the constraint/variable can be destructed.

Public Member Functions inherited from abacus::AbacusRoot
virtual	~AbacusRoot ()
	The destructor.

Protected Attributes
Row	row_
	The representation of the constraint.

Protected Attributes inherited from abacus::Constraint
ConClass *	conClass_

bool	liftable_
	This member is true if also coefficients of variables which have been inactive at generation time can be computed, false otherwise.

double	rhs_
	The right hand side of the constraint.

CSense	sense_
	The sense of the constraint.

Protected Attributes inherited from abacus::ConVar
bool	dynamic_
	If this member is true then the constraint/variable can be also removed from the active formulation after it is added the first time.

bool	expanded_
	true, if expanded version of constraint/variables available.

bool	local_
	true if the constraint/variable is only locally valid

Master *	master_
	A pointer to the corresponding master of the optimization.

int	nActive_
	The number of active subproblems of which the constraint/variable belongs to the set of active constraints/variables.

int	nLocks_
	The number of locks which have been set on the constraint/variable.

int	nReferences_
	The number of references to the pool slot the constraint is stored in.

const Sub *	sub_
	A pointer to the subproblem associated with the constraint/variable.

Additional Inherited Members
Static Public Member Functions inherited from abacus::AbacusRoot
static bool	ascii2bool (const string &str)
	Converts the string str to a boolean value.

static bool	endsWith (const string &str, const string &end)
	Returns true if str ends with end, false otherwise.

static double	fracPart (double x)
	Returns the absolute value of the fractional part of x.

static const char *	onOff (bool value)
	Converts a boolean variable to the strings "on" and "off".

Protected Member Functions inherited from abacus::Constraint
virtual ConClass *	classify (Active< Variable, Constraint > *var) const
	The default implementation returns a 0 pointer.

virtual InfeasCon::INFEAS	voidLhsViolated (double newRhs) const
	Can be called if after variable elimination the left hand side of the constraint has become void and the right hand side has been adapted to newRhs.

Detailed Description

Implements constraints stored in the class Row.

Earlier we explained that we distinguish between the constraint and the row format. We have seen already that a constraint is transformed to the row format when it is added to the linear program. However, for some constraints of certain optimization problems the row format itself is the most suitable representation. Therefore the class RowCon implements constraints stored in the class Row.

Definition at line 49 of file rowcon.h.

Constructor & Destructor Documentation

◆ RowCon() [1/2]

abacus::RowCon::RowCon	(	Master *	master,
		const Sub *	sub,
		CSense::SENSE	sense,
		int	nnz,
		const Array< int > &	support,
		const Array< double > &	coeff,
		double	rhs,
		bool	dynamic,
		bool	local,
		bool	liftable
	)

inline

Creates a row constraint.

Parameters

master	A pointer to the corresponding master of the optimization.
sub	A pointer to the subproblem associated with the constraint. This can also be the 0-pointer.
sense	The sense of the constraint.
nnz	The number of nonzero elements of the constraint.
support	The array storing the variables with nonzero coefficients.
coeff	The nonzero coefficients of the variables stored in support.
rhs	The right hand side of the constraint.
dynamic	If this argument is true, then the constraint can be removed from the active constraint set during the cutting plane phase of the subproblem optimization.
local	If this argument is true, then the constraint is considered to be only locally valid. As a locally valid constraint is associated with a subproblem, sub must not be 0 if local is true.
liftable	If this argument is true, then a lifting procedure must be available, i.e., that the coefficients of variables which have not been active at generation time of the constraint can be computed.

Definition at line 72 of file rowcon.h.

◆ RowCon() [2/2]

abacus::RowCon::RowCon	(	Master *	master,
		const Sub *	sub,
		CSense::SENSE	sense,
		int	nnz,
		int *	support,
		double *	coeff,
		double	rhs,
		bool	dynamic,
		bool	local,
		bool	liftable
	)

inline

Creates a row constraint.

Parameters

master	A pointer to the corresponding master of the optimization.
sub	A pointer to the subproblem associated with the constraint. This can also be the 0-pointer.
sense	The sense of the constraint.
nnz	The number of nonzero elements of the constraint.
support	The array storing the variables with nonzero coefficients.
coeff	The nonzero coefficients of the variables stored in support.
rhs	The right hand side of the constraint.
dynamic	If this argument is true, then the constraint can be removed from the active constraint set during the cutting plane phase of the subproblem optimization.
local	If this argument is true, then the constraint is considered to be only locally valid. As a locally valid constraint is associated with a subproblem, sub must not be 0 if local is true.
liftable	If this argument is true, then a lifting procedure must be available, i.e., that the coefficients of variables which have not been active at generation time of the constraint can be computed.

Definition at line 107 of file rowcon.h.

◆ ~RowCon()

virtual abacus::RowCon::~RowCon ( )

inlinevirtual

The destructor.

Definition at line 123 of file rowcon.h.

Member Function Documentation

◆ coeff()

virtual double abacus::RowCon::coeff ( const Variable * v ) const

inlineoverridevirtual

Computes the coefficient of a variable which must be of type NumVar.

It redefines the virtual function coeff() of the base class Constraint.

Warning: The worst case complexity of the call of this function is the number of nonzero elements of the constraint.

Parameters

v	The variable of which the coefficient is determined.

Returns: The coefficient of the variable v.

Implements abacus::Constraint.

Definition at line 136 of file rowcon.h.

◆ print()

virtual void abacus::RowCon::print ( std::ostream & out ) const

inlineoverridevirtual

Writes the row format of the constraint on an output stream.

It redefines the virtual function print() of the base class ConVar.

Parameters

out	The output stream.

Reimplemented from abacus::ConVar.

Definition at line 147 of file rowcon.h.

◆ row() [1/2]

Row * abacus::RowCon::row ( )

inline

Returns a pointer to the object of the class Row representing the constraint.

Definition at line 152 of file rowcon.h.

◆ row() [2/2]

const Row * abacus::RowCon::row ( ) const

inline

Returns a const pointer to the object of the class Row representing the constraint.

Definition at line 155 of file rowcon.h.

Member Data Documentation

◆ row_

Row abacus::RowCon::row_

protected

The representation of the constraint.

Definition at line 159 of file rowcon.h.

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

include/ogdf/lib/abacus/rowcon.h

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Public Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ RowCon() [1/2]

◆ RowCon() [2/2]

◆ ~RowCon()

Member Function Documentation

◆ coeff()

◆ print()

◆ row() [1/2]

◆ row() [2/2]

Member Data Documentation

◆ row_

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