gko::Perturbation< ValueType > Class Template Reference

The Perturbation class can be used to construct a LinOp to represent the operation (identity + scalar * basis * projector). More...

#include <ginkgo/core/base/perturbation.hpp>

Inheritance diagram for gko::Perturbation< ValueType >:

Collaboration diagram for gko::Perturbation< ValueType >:

Public Types
using	value_type = ValueType
Public Types inherited from gko::EnablePolymorphicAssignment< Perturbation< default_precision > >
using	result_type

Public Member Functions
const std::shared_ptr< const LinOp >	get_basis () const noexcept
	Returns the basis of the perturbation.
const std::shared_ptr< const LinOp >	get_projector () const noexcept
	Returns the projector of the perturbation.
const std::shared_ptr< const LinOp >	get_scalar () const noexcept
	Returns the scalar of the perturbation.
Perturbation &	operator= (const Perturbation &other)
Perturbation &	operator= (Perturbation &&other)
	Perturbation (const Perturbation &other)
	Perturbation (Perturbation &&other)
Public Member Functions inherited from gko::EnableLinOp< Perturbation< default_precision > >
const Perturbation< default_precision > *	apply (ptr_param< const LinOp > b, ptr_param< LinOp > x) const
Public Member Functions inherited from gko::EnablePolymorphicAssignment< Perturbation< default_precision > >
void	convert_to (result_type *result) const override
void	move_to (result_type *result) override

Static Public Member Functions
static std::unique_ptr< Perturbation >	create (std::shared_ptr< const Executor > exec)
	Creates an empty perturbation operator (0x0 operator).
static std::unique_ptr< Perturbation >	create (std::shared_ptr< const LinOp > scalar, std::shared_ptr< const LinOp > basis)
	Creates a perturbation with scalar and basis by setting projector to the conjugate transpose of basis.
static std::unique_ptr< Perturbation >	create (std::shared_ptr< const LinOp > scalar, std::shared_ptr< const LinOp > basis, std::shared_ptr< const LinOp > projector)
	Creates a perturbation of scalar, basis and projector.
Static Public Member Functions inherited from gko::EnableCreateMethod< Perturbation< default_precision > >
static std::unique_ptr< Perturbation< default_precision > >	create (Args &&... args)

Friends
class	EnablePolymorphicObject< Perturbation, LinOp >
class	EnableCreateMethod< Perturbation >

Detailed Description

template<typename ValueType = default_precision>
class gko::Perturbation< ValueType >

The Perturbation class can be used to construct a LinOp to represent the operation (identity + scalar * basis * projector).

This operator adds a movement along a direction constructed by basis and projector on the LinOp. projector gives the coefficient of basis to decide the direction.

For example, the Householder matrix can be represented with the Perturbation operator as follows. If u is the Householder factor then we can generate the Householder transformation, H = (I - 2 u u*). In this case, the parameters of Perturbation class are scalar = -2, basis = u, and projector = u*.

Template Parameters

ValueType

precision of input and result vectors

Note

the apply operations of Perturbation class are not thread safe

Member Function Documentation

create() [1/3]

template<typename ValueType = default_precision>

std::unique_ptr< Perturbation > gko::Perturbation< ValueType >::create ( std::shared_ptr< const Executor > exec )

static

Creates an empty perturbation operator (0x0 operator).

Parameters

exec	Executor associated to the perturbation

Returns

A smart pointer to the newly created perturbation.

create() [2/3]

template<typename ValueType = default_precision>

std::unique_ptr< Perturbation > gko::Perturbation< ValueType >::create ( std::shared_ptr< const LinOp > scalar, std::shared_ptr< const LinOp > basis )

static

Creates a perturbation with scalar and basis by setting projector to the conjugate transpose of basis.

Basis must be transposable. Perturbation will throw gko::NotSupported if basis is not transposable.

Parameters

scalar	scaling of the movement
basis	the direction basis

Returns

A smart pointer to the newly created perturbation.

create() [3/3]

template<typename ValueType = default_precision>

std::unique_ptr< Perturbation > gko::Perturbation< ValueType >::create ( std::shared_ptr< const LinOp > scalar, std::shared_ptr< const LinOp > basis, std::shared_ptr< const LinOp > projector )

static

Creates a perturbation of scalar, basis and projector.

Parameters

scalar	scaling of the movement
basis	the direction basis
projector	decides the coefficient of basis

Returns

A smart pointer to the newly created perturbation.

get_basis()

template<typename ValueType = default_precision>

const std::shared_ptr< const LinOp > gko::Perturbation< ValueType >::get_basis ( ) const

inlinenoexcept

Returns the basis of the perturbation.

Returns

the basis of the perturbation

get_projector()

template<typename ValueType = default_precision>

const std::shared_ptr< const LinOp > gko::Perturbation< ValueType >::get_projector ( ) const

inlinenoexcept

Returns the projector of the perturbation.

Returns

the projector of the perturbation

get_scalar()

template<typename ValueType = default_precision>

const std::shared_ptr< const LinOp > gko::Perturbation< ValueType >::get_scalar ( ) const

inlinenoexcept

Returns the scalar of the perturbation.

Returns

the scalar of the perturbation

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

• ginkgo/core/base/perturbation.hpp