operations_research::glop::EtaFactorization Class Reference

#include <basis_representation.h>

Public Member Functions
	EtaFactorization ()
	EtaFactorization (const EtaFactorization &)=delete
	This type is neither copyable nor movable.
EtaFactorization &	operator= (const EtaFactorization &)=delete
virtual	~EtaFactorization ()
void	Clear ()
	Deletes all eta matrices.
void	Update (ColIndex entering_col, RowIndex leaving_variable_row, const ScatteredColumn &direction)
void	LeftSolve (DenseRow *y) const
	Left solves all systems from right to left, i.e. y_i = y_{i+1}.(E_i)^{-1}.
void	SparseLeftSolve (DenseRow *y, ColIndexVector *pos) const
void	RightSolve (DenseColumn *d) const
	Right solves all systems from left to right, i.e. E_i.d_{i+1} = d_i.

Detailed Description

An eta factorization corresponds to the product of k eta matrices, i.e. E = E_0.E_1. ... .E_{k-1} It is used to solve two systems:

• E.d = a (where a is usually the entering column).
• y.E = c (where c is usually the objective row).

Definition at line 115 of file basis_representation.h.

Constructor & Destructor Documentation

EtaFactorization() [1/2]

operations_research::glop::EtaFactorization::EtaFactorization

(

)

EtaFactorization

Definition at line 145 of file basis_representation.cc.

EtaFactorization() [2/2]

operations_research::glop::EtaFactorization::EtaFactorization ( const EtaFactorization & )

delete

This type is neither copyable nor movable.

~EtaFactorization()

operations_research::glop::EtaFactorization::~EtaFactorization ( )

virtual

Definition at line 147 of file basis_representation.cc.

Member Function Documentation

Clear()

void operations_research::glop::EtaFactorization::Clear

(

)

Deletes all eta matrices.

Definition at line 149 of file basis_representation.cc.

LeftSolve()

void operations_research::glop::EtaFactorization::LeftSolve

(

DenseRow *

y

)

const

Left solves all systems from right to left, i.e. y_i = y_{i+1}.(E_i)^{-1}.

Definition at line 160 of file basis_representation.cc.

operator=()

EtaFactorization & operations_research::glop::EtaFactorization::operator= ( const EtaFactorization & )

delete

RightSolve()

void operations_research::glop::EtaFactorization::RightSolve

(

DenseColumn *

d

)

const

Right solves all systems from left to right, i.e. E_i.d_{i+1} = d_i.

Definition at line 174 of file basis_representation.cc.

SparseLeftSolve()

void operations_research::glop::EtaFactorization::SparseLeftSolve	(	DenseRow *	y,
		ColIndexVector *	pos ) const

Same as LeftSolve(), but 'pos' contains the non-zero positions of c. The order of the positions is not important, but there must be no duplicates. The values not in 'pos' are not used. If eta_col_ was not already in 'pos', it is added.

Definition at line 167 of file basis_representation.cc.

Update()

void operations_research::glop::EtaFactorization::Update	(	ColIndex	entering_col,
		RowIndex	leaving_variable_row,
		const ScatteredColumn &	direction )

Updates the eta factorization, i.e. adds the new eta matrix defined by the leaving variable and the corresponding eta column.

Definition at line 151 of file basis_representation.cc.

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

• ortools/glop/basis_representation.h
• ortools/glop/basis_representation.cc