fftw< T > Struct Template Reference

Wrapper for a subset of FFTW: FFT's for real functions in one dimension. More...

#include <::c_api>

Classes
class	allocator
	STL allocator replacement using FFTW's memory allocation functions. More...
struct	c_api
	Specialization of c_api for double precision. More...

Public Types
typedef T	real
	Real number.
typedef std::complex< T >	complex
	Complex number.
typedef std::vector< real, allocator< real > >	real_vector
	Vector of real numbers using FFTW allocation.
typedef std::vector< complex, allocator< complex > >	complex_vector
	Vector of complex numbers using FFTW allocation.

Static Public Member Functions
static complex_vector &	fft (const real_vector &v, complex_vector &result)
	Computes the real-to-complex Fourier transform of v into result. More...
static complex_vector::size_type	fft_size (const real_vector &v)
	Returns the output size (exact) for real-to-complex Fourier transform of v. More...
static complex_vector	fft (const real_vector &v)
	Computes the real-to-complex Fourier transform of v. More...
static real_vector &	ifft (const complex_vector &v, real_vector &result, bool normalize=true)
	Computes the complex-to-real Fourier transform of v into result. More...
static real_vector::size_type	real_ifft_size (const complex_vector &v)
	Returns the output size (guessed) for complex-to-real Fourier transform of v. More...
static real_vector	real_ifft (const complex_vector &v, bool normalize=true)
	Computes the complex-to-real Fourier transform of v. More...

Detailed Description

template<typename T>
struct fftw< T >

Wrapper for a subset of FFTW: FFT's for real functions in one dimension.

Specialization of for float precision.

Member Function Documentation

fft() [1/2]

template<typename T>

static complex_vector& fftw< T >::fft ( const real_vector &  v, complex_vector &  result  )

inlinestatic

Computes the real-to-complex Fourier transform of v into result.

The size of the transform is that of the real component. The expected size of result is v.size() / 2 + 1. Because result is Hermitian, only half of the elements (plus one) are stored.

References fftw< T >::fft_size().

Referenced by fftw< T >::fft().

fft() [2/2]

template<typename T>

static complex_vector fftw< T >::fft ( const real_vector &  v )

inlinestatic

Computes the real-to-complex Fourier transform of v.

See also

transform(const real_vector&, complex_vector&)

References fftw< T >::fft(), and fftw< T >::fft_size().

fft_size()

template<typename T>

static complex_vector::size_type fftw< T >::fft_size ( const real_vector &  v )

inlinestatic

Returns the output size (exact) for real-to-complex Fourier transform of v.

See also

transform(const real_vector&, complex_vector&)

Referenced by fftw< T >::fft(), and fftw< T >::ifft().

ifft()

template<typename T>

static real_vector& fftw< T >::ifft ( const complex_vector &  v, real_vector &  result, bool  normalize = true  )

inlinestatic

Computes the complex-to-real Fourier transform of v into result.

The size of the transform is that of the real component. The expected size of v is is result.size() / 2 + 1. Because v is Hermitian, only half of the elements (plus one) are considered.

Warning

If normalize is false, the result vector is not normalized; its components must be divided by result.size() for proper normalization.

References fftw< T >::fft_size().

Referenced by fftw< T >::real_ifft(), and LatBuilder::Kernel::RAlpha::valuesVector().

real_ifft()

template<typename T>

static real_vector fftw< T >::real_ifft ( const complex_vector &  v, bool  normalize = true  )

inlinestatic

Computes the complex-to-real Fourier transform of v.

Assumes the size of the transform is 2 * (v.size() - 1). Returns a vector of size 2 * (v.size() - 1).

See also

transform(const complex_vector&, real_vector&)

References fftw< T >::ifft(), and fftw< T >::real_ifft_size().

real_ifft_size()

template<typename T>

static real_vector::size_type fftw< T >::real_ifft_size ( const complex_vector &  v )

inlinestatic

Returns the output size (guessed) for complex-to-real Fourier transform of v.

See also

transform(const complex_vector&, real_vector&)

Referenced by fftw< T >::real_ifft().

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

• include/latbuilder/fftw++.h