abacus::LPVARSTAT Class Reference

status of variables. More...

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

Inheritance diagram for abacus::LPVARSTAT:

Public Types
enum	STATUS { AtLowerBound, Basic, AtUpperBound, NonBasicFree, Eliminated, Unknown }
	The enumeration of the statuses a variable gets from the linear program solver. More...

Public Member Functions
	LPVARSTAT ()
	This constructor initializes the status as Unknown. More...
	LPVARSTAT (LPVARSTAT *lpVarStat)
	This constructor make a copy of *lpVarStat. More...
	LPVARSTAT (STATUS status)
	This constructor initializes the LPVARSTAT. More...
bool	atBound () const
	Returns true if the variable status is AtUpperBound or AtLowerBound, false otherwise. More...
bool	basic () const
	Returns true If the status is Basic, false otherwise. More...
STATUS	status () const
	Returns the LP-status. More...
void	status (const LPVARSTAT *stat)
	Sets the status to stat. More...
void	status (STATUS stat)
	Sets the status to stat. More...
Public Member Functions inherited from abacus::AbacusRoot
virtual	~AbacusRoot ()
	The destructor. More...

Private Attributes
STATUS	status_
	The LP-status. More...

Friends
std::ostream &	operator<< (std::ostream &out, const LPVARSTAT &rhs)
	The output operator. More...

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. More...
static bool	endsWith (const string &str, const string &end)
	Returns true if str ends with end, false otherwise. More...
static double	fracPart (double x)
	Returns the absolute value of the fractional part of x. More...
static const char *	onOff (bool value)
	Converts a boolean variable to the strings "on" and "off". More...

Detailed Description

status of variables.

After the solution of a linear program by the simplex method each variable receives a status indicating if the variable is contained in the basis of the optimal solution, or is nonbasic and has a value equal to its lower or upper bound, or is a free variable not contained in the basis. We extend this notion since later in the interface from a cutting plane algorithm to the linear program variables might be eliminated.

Definition at line 50 of file lpvarstat.h.

Member Enumeration Documentation

STATUS

enum abacus::LPVARSTAT::STATUS

The enumeration of the statuses a variable gets from the linear program solver.

Enumerator
AtLowerBound	The variable is at its lower bound, but not in the basis.
Basic	The variable is in the basis.
AtUpperBound	The variable is at its upper bound , but not in the basis.
NonBasicFree	The variable is unbounded and not in the basis.
Eliminated	The variable has been removed by our preprocessor in the class LpSub. So, it is not present in the LP-solver.
Unknown	The LP-status of the variable is unknown since no LP has been solved. This status is also assigned to variables which are fixed or set, yet still contained in the LP to avoid a wrong setting or fixing by reduced costs.

Definition at line 54 of file lpvarstat.h.

Constructor & Destructor Documentation

LPVARSTAT() [1/3]

abacus::LPVARSTAT::LPVARSTAT ( )

inline

This constructor initializes the status as Unknown.

Definition at line 70 of file lpvarstat.h.

LPVARSTAT() [2/3]

abacus::LPVARSTAT::LPVARSTAT ( STATUS  status )

inline

This constructor initializes the LPVARSTAT.

Parameters

status

The initial status.

Definition at line 76 of file lpvarstat.h.

LPVARSTAT() [3/3]

abacus::LPVARSTAT::LPVARSTAT ( LPVARSTAT *  lpVarStat )

inline

This constructor make a copy of *lpVarStat.

Parameters

lpVarStat

A copy of this object is made.

Definition at line 82 of file lpvarstat.h.

Member Function Documentation

atBound()

bool abacus::LPVARSTAT::atBound ( ) const

inline

Returns true if the variable status is AtUpperBound or AtLowerBound, false otherwise.

Definition at line 115 of file lpvarstat.h.

basic()

bool abacus::LPVARSTAT::basic ( ) const

inline

Returns true If the status is Basic, false otherwise.

Definition at line 120 of file lpvarstat.h.

status() [1/3]

STATUS abacus::LPVARSTAT::status ( ) const

inline

Returns the LP-status.

Definition at line 100 of file lpvarstat.h.

status() [2/3]

void abacus::LPVARSTAT::status ( const LPVARSTAT *  stat )

inline

Sets the status to stat.

Parameters

stat	The new LP-status.

Definition at line 112 of file lpvarstat.h.

status() [3/3]

void abacus::LPVARSTAT::status ( STATUS  stat )

inline

Sets the status to stat.

Parameters

stat	The new LP-status.

Definition at line 106 of file lpvarstat.h.

Friends And Related Function Documentation

operator<<

std::ostream& operator<< ( std::ostream &  out, const LPVARSTAT &  rhs  )

friend

The output operator.

Writes the STATUS to an output stream in the form AtLowerBound, Basic, AtUpperBound, NonBasicFree, Eliminated, Unknown.

Parameters

out	The output stream.
rhs	The status being output.

Returns

A reference to the output stream.

Member Data Documentation

status_

STATUS abacus::LPVARSTAT::status_

private

The LP-status.

Definition at line 128 of file lpvarstat.h.

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

• include/ogdf/lib/abacus/lpvarstat.h