ClpDualRowSteepest Class Reference

Dual Row Pivot Steepest Edge Algorithm Class. More...

#include <ClpDualRowSteepest.hpp>

Inheritance diagram for ClpDualRowSteepest:

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Collaboration diagram for ClpDualRowSteepest:

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List of all members.

Public Types
enum	Persistence { normal = 0x00, keep = 0x01 }
	enums for persistence More...
Public Member Functions
Algorithmic methods

virtual int	pivotRow ()
	Returns pivot row, -1 if none.
virtual double	updateWeights (CoinIndexedVector input, CoinIndexedVector spare, CoinIndexedVector *updatedColumn)
	Updates weights and returns pivot alpha.
virtual void	updatePrimalSolution (CoinIndexedVector *input, double theta, double &changeInObjective)
	Updates primal solution (and maybe list of candidates) Uses input vector which it deletes Computes change in objective function.
virtual void	saveWeights (ClpSimplex *model, int mode)
	Saves any weights round factorization as pivot rows may change 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	unrollWeights ()
	Gets rid of last update.
virtual void	clearArrays ()
	Gets rid of all arrays.
virtual bool	looksOptimal () const
	Returns true if would not find any row.
virtual void	maximumPivotsChanged ()
	Called when maximum pivots changes.
Constructors and destructors

	ClpDualRowSteepest (int mode=3)
	Default Constructor 0 is uninitialized, 1 full, 2 is partial uninitialized, 3 starts as 2 but may switch to 1.
	ClpDualRowSteepest (const ClpDualRowSteepest &)
	Copy constructor.
ClpDualRowSteepest &	operator= (const ClpDualRowSteepest &rhs)
	Assignment operator.
virtual	~ClpDualRowSteepest ()
	Destructor.
virtual ClpDualRowPivot *	clone (bool copyData=true) const
	Clone.
gets and sets

int	mode () const
	Mode.
void	setPersistence (Persistence life)
	Set/ get persistence.
Persistence	persistence () const
	Mode.
Private Attributes
Private member data

int	state_
	Status 0) Normal -1) Needs initialization 1) Weights are stored by sequence number.
int	mode_
	If 0 then we are using uninitialized weights, 1 then full, if 2 then uninitialized partial, 3 switchable.
Persistence	persistence_
	Life of weights.
double *	weights_
	weight array
CoinIndexedVector *	infeasible_
	square of infeasibility array (just for infeasible rows)
CoinIndexedVector *	alternateWeights_
	alternate weight array (so we can unroll)
CoinIndexedVector *	savedWeights_
	save weight array (so we can use checkpoint)
int *	dubiousWeights_
	Dubious weights.

Detailed Description

Dual Row Pivot Steepest Edge Algorithm Class.

See Forrest-Goldfarb paper for algorithm

Definition at line 18 of file ClpDualRowSteepest.hpp.

Member Enumeration Documentation

enum ClpDualRowSteepest::Persistence

enums for persistence

Enumerator:

normal
keep

Definition at line 64 of file ClpDualRowSteepest.hpp.

Constructor & Destructor Documentation

ClpDualRowSteepest::ClpDualRowSteepest ( int mode = 3 )

Default Constructor 0 is uninitialized, 1 full, 2 is partial uninitialized, 3 starts as 2 but may switch to 1.

By partial is meant that the weights are updated as normal but only part of the infeasible basic variables are scanned. This can be faster on very easy problems.

ClpDualRowSteepest::ClpDualRowSteepest ( const ClpDualRowSteepest & )

Copy constructor.

virtual ClpDualRowSteepest::~ClpDualRowSteepest ( ) [virtual]

Destructor.

Member Function Documentation

virtual int ClpDualRowSteepest::pivotRow ( ) [virtual]

Returns pivot row, -1 if none.

Implements ClpDualRowPivot.

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

Updates weights and returns pivot alpha.

Implements ClpDualRowPivot.

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

Updates primal solution (and maybe list of candidates) Uses input vector which it deletes Computes change in objective function.

Implements ClpDualRowPivot.

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

Saves any weights round factorization as pivot rows may change 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 (uninitialized) , infeasibilities

Reimplemented from ClpDualRowPivot.

virtual void ClpDualRowSteepest::unrollWeights ( ) [virtual]

Gets rid of last update.

Reimplemented from ClpDualRowPivot.

virtual void ClpDualRowSteepest::clearArrays ( ) [virtual]

Gets rid of all arrays.

Reimplemented from ClpDualRowPivot.

virtual bool ClpDualRowSteepest::looksOptimal ( ) const [virtual]

Returns true if would not find any row.

Reimplemented from ClpDualRowPivot.

virtual void ClpDualRowSteepest::maximumPivotsChanged ( ) [virtual]