gko::matrix::Fft2 Class Reference

This LinOp implements a 2D Fourier matrix using the FFT algorithm. More...

#include <ginkgo/core/matrix/fft.hpp>

Inheritance diagram for gko::matrix::Fft2:

Collaboration diagram for gko::matrix::Fft2:

Public Types
using	value_type = std::complex<double>
using	index_type = int64
using	transposed_type = Fft2
Public Types inherited from gko::EnablePolymorphicAssignment< Fft2 >
using	result_type

Public Member Functions
std::unique_ptr< LinOp >	transpose () const override
	Returns a LinOp representing the transpose of the Transposable object.
std::unique_ptr< LinOp >	conj_transpose () const override
	Returns a LinOp representing the conjugate transpose of the Transposable object.
void	write (matrix_data< std::complex< float >, int32 > &data) const override
void	write (matrix_data< std::complex< float >, int64 > &data) const override
void	write (matrix_data< std::complex< double >, int32 > &data) const override
void	write (matrix_data< std::complex< double >, int64 > &data) const override
dim< 2 >	get_fft_size () const
bool	is_inverse () const
Public Member Functions inherited from gko::EnableLinOp< Fft2 >
const Fft2 *	apply (ptr_param< const LinOp > b, ptr_param< LinOp > x) const
Public Member Functions inherited from gko::EnablePolymorphicAssignment< Fft2 >
void	convert_to (result_type *result) const override
void	move_to (result_type *result) override

Static Public Member Functions
static std::unique_ptr< Fft2 >	create (std::shared_ptr< const Executor > exec)
	Creates an empty Fourier matrix.
static std::unique_ptr< Fft2 >	create (std::shared_ptr< const Executor > exec, size_type size)
	Creates an Fourier matrix with the given dimensions.
static std::unique_ptr< Fft2 >	create (std::shared_ptr< const Executor > exec, size_type size1, size_type size2, bool inverse=false)
	Creates an Fourier matrix with the given dimensions.

Friends
class	EnablePolymorphicObject< Fft2, LinOp >

Detailed Description

This LinOp implements a 2D Fourier matrix using the FFT algorithm.

For indexing purposes, the first dimension is the major axis.

It implements complex-to-complex forward and inverse FFT.

For a power-of-two sizes with corresponding root of unity for forward DFT and for inverse DFT it computes

without normalization factors.

The Reference and OpenMP implementations support only power-of-two input sizes, as they use the Radix-2 algorithm by J. W. Cooley and J. W. Tukey, "An Algorithm for the Machine Calculation of Complex Fourier Series," Mathematics of Computation, vol. 19, no. 90, pp. 297–301, 1965, doi: 10.2307/2003354. The CUDA and HIP implementations use cuSPARSE/hipSPARSE with full support for non-power-of-two input sizes and special optimizations for products of small prime powers.

Member Function Documentation

conj_transpose()

std::unique_ptr< LinOp > gko::matrix::Fft2::conj_transpose ( ) const

overridevirtual

Returns a LinOp representing the conjugate transpose of the Transposable object.

Returns

a pointer to the new conjugate transposed object

Implements gko::Transposable.

create() [1/3]

std::unique_ptr< Fft2 > gko::matrix::Fft2::create ( std::shared_ptr< const Executor > exec )

static

Creates an empty Fourier matrix.

Parameters

exec	Executor associated to the matrix

Returns

A smart pointer to the newly created matrix.

create() [2/3]

std::unique_ptr< Fft2 > gko::matrix::Fft2::create ( std::shared_ptr< const Executor > exec, size_type size )

static

Creates an Fourier matrix with the given dimensions.

Parameters

size	size of both FFT dimensions

Returns

A smart pointer to the newly created matrix.

create() [3/3]

std::unique_ptr< Fft2 > gko::matrix::Fft2::create ( std::shared_ptr< const Executor > exec, size_type size1, size_type size2, bool inverse = false )

static

Creates an Fourier matrix with the given dimensions.

Parameters

size1	size of the first FFT dimension
size2	size of the second FFT dimension
inverse	true to compute an inverse DFT instead of a normal DFT

Returns

A smart pointer to the newly created matrix.

transpose()

std::unique_ptr< LinOp > gko::matrix::Fft2::transpose ( ) const

overridevirtual

Returns a LinOp representing the transpose of the Transposable object.

Returns

a pointer to the new transposed object

Implements gko::Transposable.

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

• ginkgo/core/matrix/fft.hpp