ClpDualRowPivot Class Reference

Dual Row Pivot Abstract Base Class. More...

#include <ClpDualRowPivot.hpp>

Inheritance diagram for ClpDualRowPivot:

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Collaboration diagram for ClpDualRowPivot:

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List of all members.

Public Member Functions
Algorithmic methods

virtual int	pivotRow ()=0
	Returns pivot row, -1 if none.
virtual double	updateWeights (CoinIndexedVector input, CoinIndexedVector spare, CoinIndexedVector *updatedColumn)=0
	Updates weights and returns pivot alpha.
virtual void	updatePrimalSolution (CoinIndexedVector *input, double theta, double &changeInObjective)=0
	Updates primal solution (and maybe list of candidates) Uses input vector which it deletes Computes change in objective function Would be faster if we kept basic regions, but on other hand it means everything is always in sync.
virtual void	saveWeights (ClpSimplex *model, int mode)
	Saves any weights round factorization as pivot rows may change Will be empty unless steepest edge (will save model) May also recompute infeasibility stuff 1) before factorization 2) after good factorization (if weights empty may initialize) 3) after something happened but no factorization (e.g.
virtual void	checkAccuracy ()
	checks accuracy and may re-initialize (may be empty)
virtual void	unrollWeights ()
	Gets rid of last update (may be empty).
virtual void	clearArrays ()
	Gets rid of all arrays (may be empty).
virtual bool	looksOptimal () const
	Returns true if would not find any row.
virtual void	maximumPivotsChanged ()
	Called when maximum pivots changes.
Constructors and destructors

	ClpDualRowPivot ()
	Default Constructor.
	ClpDualRowPivot (const ClpDualRowPivot &)
	Copy constructor.
ClpDualRowPivot &	operator= (const ClpDualRowPivot &rhs)
	Assignment operator.
virtual	~ClpDualRowPivot ()
	Destructor.
virtual ClpDualRowPivot *	clone (bool copyData=true) const =0
	Clone.
Other

ClpSimplex *	model ()
	Returns model.
int	type ()
	Returns type (above 63 is extra information).
Protected Attributes
Protected member data

ClpSimplex *	model_
	Pointer to model.
int	type_
	Type of row pivot algorithm.

Detailed Description

Dual Row Pivot Abstract Base Class.

Abstract Base Class for describing an interface to an algorithm to choose row pivot in dual simplex algorithm. For some algorithms e.g. Dantzig choice then some functions may be null.

Definition at line 19 of file ClpDualRowPivot.hpp.

Constructor & Destructor Documentation

ClpDualRowPivot::ClpDualRowPivot ( )

Default Constructor.

ClpDualRowPivot::ClpDualRowPivot ( const ClpDualRowPivot & )

Copy constructor.

virtual ClpDualRowPivot::~ClpDualRowPivot ( ) [virtual]

Destructor.

Member Function Documentation

virtual int ClpDualRowPivot::pivotRow ( ) [pure virtual]

Returns pivot row, -1 if none.

Implemented in ClpDualRowDantzig, and ClpDualRowSteepest.

virtual double ClpDualRowPivot::updateWeights	(	CoinIndexedVector *	input,
		CoinIndexedVector *	spare,
		CoinIndexedVector *	updatedColumn
	)			`[pure virtual]`

Updates weights and returns pivot alpha.

Implemented in ClpDualRowDantzig, and ClpDualRowSteepest.

virtual void ClpDualRowPivot::updatePrimalSolution	(	CoinIndexedVector *	input,
		double	theta,
		double &	changeInObjective
	)			`[pure virtual]`

Updates primal solution (and maybe list of candidates) Uses input vector which it deletes Computes change in objective function Would be faster if we kept basic regions, but on other hand it means everything is always in sync.

Implemented in ClpDualRowDantzig, and ClpDualRowSteepest.

virtual void ClpDualRowPivot::saveWeights	(	ClpSimplex *	model,
		int	mode
	)			`[virtual]`

Saves any weights round factorization as pivot rows may change Will be empty unless steepest edge (will save model) May also recompute infeasibility stuff 1) before factorization 2) after good factorization (if weights empty may initialize) 3) after something happened but no factorization (e.g.

check for infeasible) 4) as 2 but restore weights from previous snapshot 5) for strong branching - initialize , infeasibilities

Reimplemented in ClpDualRowSteepest.

virtual void ClpDualRowPivot::checkAccuracy ( ) [virtual]

checks accuracy and may re-initialize (may be empty)

virtual void ClpDualRowPivot::unrollWeights ( ) [virtual]

Gets rid of last update (may be empty).

Reimplemented in ClpDualRowSteepest.

virtual void ClpDualRowPivot::clearArrays ( ) [virtual]

Gets rid of all arrays (may be empty).

Reimplemented in ClpDualRowSteepest.

virtual bool ClpDualRowPivot::looksOptimal ( ) const [inline, virtual]

Returns true if would not find any row.