ndarray::FourierTransform< T, N > Class Template Reference

A wrapper for FFTW plans for fast Fourier transforms. More...

#include <FourierTransform.h>

Inheritance diagram for ndarray::FourierTransform< T, N >:

Public Types
typedef boost::shared_ptr < FourierTransform >	Ptr
typedef detail::FourierTraits < T >::ElementX	ElementX
	Real-space array data type;. More...
typedef detail::FourierTraits < T >::ElementK	ElementK
	Fourier-space array data type;. More...
typedef Vector< int, N >	Index
	Shape type for arrays. More...
typedef Array< ElementX, N, N >	ArrayX
	Real-space array type. More...
typedef Array< ElementK, N, N >	ArrayK
	Fourier-space array type. More...
typedef Vector< int, N+1 >	MultiplexIndex
	Shape type for multiplexed arrays. More...
typedef Array< ElementX, N+1, N+1 >	MultiplexArrayX
	Real-space multiplexed array type. More...
typedef Array< ElementK, N+1, N+1 >	MultiplexArrayK
	Fourier-space multiplexed array type. More...

Public Member Functions
void	execute ()
	Execute the FFTW plan. More...
	~FourierTransform ()
template<int M>
Array< typename FourierTransform< T, N > ::ElementX, M, M >	initializeX (Vector< int, M > const &shape)
template<int M>
Array< typename FourierTransform< T, N > ::ElementK, M, M >	initializeK (Vector< int, M > const &shape)

Static Public Member Functions
static Ptr	planForward (Index const &shape, ArrayX &x, ArrayK &k)
	Create a plan for forward-transforming a single N-dimensional array. More...
static Ptr	planInverse (Index const &shape, ArrayK &k, ArrayX &x)
	Create a plan for inverse-transforming a single N-dimensional array. More...
static Ptr	planMultiplexForward (MultiplexIndex const &shape, MultiplexArrayX &x, MultiplexArrayK &k)
	Create a plan for forward-transforming a sequence of nested N-dimensional arrays. More...
static Ptr	planMultiplexInverse (MultiplexIndex const &shape, MultiplexArrayK &k, MultiplexArrayX &x)
	Create a plan for inverse-transforming a sequence of nested N-dimensional arrays. More...
template<int M>
static Array< ElementX, M, M >	initializeX (Vector< int, M > const &shape)
	Create a new real-space array with the given real-space shape. More...
template<int M>
static Array< ElementK, M, M >	initializeK (Vector< int, M > const &shape)
	Create a new Fourier-space array with the given real-space shape. More...
template<int M>
static void	initialize (Vector< int, M > const &shape, Array< ElementX, M, M > &x, Array< ElementK, M, M > &k)
	Initialize, as necessary, a pair of arrays with the given real-space shape. More...

Private Types
typedef boost::shared_ptr < ElementX >	OwnerX
typedef boost::shared_ptr < ElementK >	OwnerK

Private Member Functions
	BOOST_STATIC_ASSERT ((!boost::is_const< T >::value))
	FourierTransform (void *plan, Manager::Ptr const &x, Manager::Ptr const &k)

Private Attributes
void *	_plan
Manager::Ptr	_x
Manager::Ptr	_k

Detailed Description

template<typename T, int N>
class ndarray::FourierTransform< T, N >

A wrapper for FFTW plans for fast Fourier transforms.

An instance of FourierTransform holds an FFTW "plan", providing repeated forward or inverse FFTs of predetermined arrays.

Multiplex plans can also be generated to perform an N-dimensional FFT on the nested arrays of an (N+1)-dimensional array.

Static member functions of FourierTransform are used to create instances, and optionally initialize the involved arrays.

Definition at line 54 of file FourierTransform.h.

Member Typedef Documentation

template<typename T, int N>

typedef Array<ElementK,N,N> ndarray::FourierTransform< T, N >::ArrayK

Fourier-space array type.

Definition at line 65 of file FourierTransform.h.

template<typename T, int N>

typedef Array<ElementX,N,N> ndarray::FourierTransform< T, N >::ArrayX

Real-space array type.

Definition at line 64 of file FourierTransform.h.

template<typename T, int N>

typedef detail::FourierTraits<T>::ElementK ndarray::FourierTransform< T, N >::ElementK

Fourier-space array data type;.

Definition at line 61 of file FourierTransform.h.

template<typename T, int N>

typedef detail::FourierTraits<T>::ElementX ndarray::FourierTransform< T, N >::ElementX

Real-space array data type;.

Definition at line 60 of file FourierTransform.h.

template<typename T, int N>

typedef Vector<int,N> ndarray::FourierTransform< T, N >::Index

Shape type for arrays.

Definition at line 63 of file FourierTransform.h.

template<typename T, int N>

typedef Array<ElementK,N+1,N+1> ndarray::FourierTransform< T, N >::MultiplexArrayK

Fourier-space multiplexed array type.

Definition at line 68 of file FourierTransform.h.

template<typename T, int N>

typedef Array<ElementX,N+1,N+1> ndarray::FourierTransform< T, N >::MultiplexArrayX

Real-space multiplexed array type.

Definition at line 67 of file FourierTransform.h.

template<typename T, int N>

typedef Vector<int,N+1> ndarray::FourierTransform< T, N >::MultiplexIndex

Shape type for multiplexed arrays.

Definition at line 66 of file FourierTransform.h.

template<typename T, int N>

typedef boost::shared_ptr<ElementK> ndarray::FourierTransform< T, N >::OwnerK

private

Definition at line 141 of file FourierTransform.h.

template<typename T, int N>

typedef boost::shared_ptr<ElementX> ndarray::FourierTransform< T, N >::OwnerX

private

Definition at line 140 of file FourierTransform.h.

template<typename T, int N>

typedef boost::shared_ptr<FourierTransform> ndarray::FourierTransform< T, N >::Ptr

Definition at line 58 of file FourierTransform.h.

Constructor & Destructor Documentation

template<typename T , int N>

ndarray::FourierTransform< T, N >::~FourierTransform

(

)

Definition at line 156 of file FourierTransform.cc.

                                         {
    detail::FFTWTraits<T>::destroy(
        reinterpret_cast<typename detail::FFTWTraits<T>::Plan>(_plan)
    );
}

template<typename T, int N>

ndarray::FourierTransform< T, N >::FourierTransform ( void *  plan, Manager::Ptr const &  x, Manager::Ptr const &  k  )

inlineprivate

Definition at line 143 of file FourierTransform.h.

        : _plan(plan), _x(x), _k(k) {}

Member Function Documentation

template<typename T, int N>

ndarray::FourierTransform< T, N >::BOOST_STATIC_ASSERT ( (!boost::is_const< T >::value)  )

private

template<typename T , int N>

void ndarray::FourierTransform< T, N >::execute

(

)

Execute the FFTW plan.

Definition at line 149 of file FourierTransform.cc.

                                    {
    detail::FFTWTraits<T>::execute(
        reinterpret_cast<typename detail::FFTWTraits<T>::Plan>(_plan)
    );
}

template<typename T , int N>

template<int M>

void ndarray::FourierTransform< T, N >::initialize ( Vector< int, M > const &  shape, Array< ElementX, M, M > &  x, Array< ElementK, M, M > &  k  )

static

Initialize, as necessary, a pair of arrays with the given real-space shape.

If either array is not empty, it must be consistent with the given shape.

Definition at line 49 of file FourierTransform.cc.

  {
    if (x.empty()) x = initializeX(shape);
    if (k.empty()) k = initializeK(shape);
    NDARRAY_ASSERT(x.getShape() == shape);
    NDARRAY_ASSERT(std::equal(shape.begin(), shape.end()-1, k.getShape().begin()));
}

template<typename T, int N>

template<int M>

Array<typename FourierTransform<T,N>::ElementK,M,M> ndarray::FourierTransform< T, N >::initializeK

(

Vector< int, M > const &

shape

)

Definition at line 39 of file FourierTransform.cc.

                                                              {
    Vector<int,M> kShape(shape);
    kShape[M-1] = detail::FourierTraits<T>::computeLastDimensionSize(shape[M-1]);
    OwnerK kOwner = detail::FFTWTraits<T>::allocateK(kShape.product());
    return Array<ElementK,M,M>(external(kOwner.get(), kShape, ROW_MAJOR, kOwner));
}

template<typename T, int N>

template<int M>

static Array<ElementK,M,M> ndarray::FourierTransform< T, N >::initializeK ( Vector< int, M > const &  shape )

static

Create a new Fourier-space array with the given real-space shape.

template<typename T, int N>

template<int M>

Array<typename FourierTransform<T,N>::ElementX,M,M> ndarray::FourierTransform< T, N >::initializeX

(

Vector< int, M > const &

shape

)

Definition at line 31 of file FourierTransform.cc.

                                                              {
    OwnerX xOwner = detail::FFTWTraits<T>::allocateX(shape.product());
    return Array<ElementX,M,M>(external(xOwner.get(), shape, ROW_MAJOR, xOwner));
}

template<typename T, int N>

template<int M>

static Array<ElementX,M,M> ndarray::FourierTransform< T, N >::initializeX ( Vector< int, M > const &  shape )

static

Create a new real-space array with the given real-space shape.

template<typename T, int N>

FourierTransform< T, N >::Ptr ndarray::FourierTransform< T, N >::planForward ( Index const &  shape, ArrayX &  x, ArrayK &  k  )

static

Create a plan for forward-transforming a single N-dimensional array.

Arrays will be initialized with new memory if empty. If they are not empty, existing data may be overwritten when the plan is created.

Parameters

shape	Shape of the real-space array.
x	Input real-space array.
k	Output Fourier-space array.

Definition at line 62 of file FourierTransform.cc.

  {
    initialize(shape,x,k);
    return Ptr(
        new FourierTransform(
            detail::FFTWTraits<T>::forward(
                N, shape.begin(), 1,
                x.getData(), NULL, 1, 0,
                k.getData(), NULL, 1, 0,
                FFTW_MEASURE | FFTW_DESTROY_INPUT
            ),
            x.getManager(),
            k.getManager()
        )
    );
}

template<typename T, int N>

FourierTransform< T, N >::Ptr ndarray::FourierTransform< T, N >::planInverse ( Index const &  shape, ArrayK &  k, ArrayX &  x  )

static

Create a plan for inverse-transforming a single N-dimensional array.

Arrays will be initialized with new memory if empty. If they are not empty, existing data may be overwritten when the plan is created.

Parameters

shape	Shape of the real-space array.
k	Input Fourier-space array.
x	Output real-space array.

Definition at line 84 of file FourierTransform.cc.

  {
    initialize(shape,x,k);
    return Ptr(
        new FourierTransform(
            detail::FFTWTraits<T>::inverse(
                N, shape.begin(), 1,
                k.getData(), NULL, 1, 0,
                x.getData(), NULL, 1, 0,
                FFTW_MEASURE | FFTW_DESTROY_INPUT
            ),
            x.getManager(),
            k.getManager()
        )
    );
}

template<typename T, int N>

FourierTransform< T, N >::Ptr ndarray::FourierTransform< T, N >::planMultiplexForward ( MultiplexIndex const &  shape, MultiplexArrayX &  x, MultiplexArrayK &  k  )

static

Create a plan for forward-transforming a sequence of nested N-dimensional arrays.

Arrays will be initialized with new memory if empty. If they are not empty, existing data may be overwritten when the plan is created.

Parameters

shape	Shape of the real-space array. First dimension is multiplexed.
x	Input real-space array.
k	Output Fourier-space array.

Definition at line 106 of file FourierTransform.cc.

  {
    initialize(shape,x,k);
    return Ptr(
        new FourierTransform(
            detail::FFTWTraits<T>::forward(
                N, shape.begin()+1, shape[0],
                x.getData(), NULL, 1, x.template getStride<0>(),
                k.getData(), NULL, 1, k.template getStride<0>(),
                FFTW_MEASURE | FFTW_DESTROY_INPUT
            ),
            x.getManager(),
            k.getManager()
        )
    );
}

template<typename T, int N>

FourierTransform< T, N >::Ptr ndarray::FourierTransform< T, N >::planMultiplexInverse ( MultiplexIndex const &  shape, MultiplexArrayK &  k, MultiplexArrayX &  x  )

static

Create a plan for inverse-transforming a sequence of nested N-dimensional arrays.

Arrays will be initialized with new memory if empty. If they are not empty, existing data may be overwritten when the plan is created.

Parameters

shape	Shape of the real-space array. First dimension is multiplexed.
k	Input Fourier-space array.
x	Output real-space array.

Definition at line 128 of file FourierTransform.cc.

  {
    initialize(shape,x,k);
    return Ptr(
        new FourierTransform(
            detail::FFTWTraits<T>::inverse(
                N, shape.begin()+1, shape[0],
                k.getData(), NULL, 1, k.template getStride<0>(),
                x.getData(), NULL, 1, x.template getStride<0>(),
                FFTW_MEASURE | FFTW_DESTROY_INPUT
            ),
            x.getManager(),
            k.getManager()
        )
    );
}

Member Data Documentation

template<typename T, int N>

Manager::Ptr ndarray::FourierTransform< T, N >::_k

private

Definition at line 148 of file FourierTransform.h.

template<typename T, int N>

void* ndarray::FourierTransform< T, N >::_plan

private

Definition at line 146 of file FourierTransform.h.

template<typename T, int N>

Manager::Ptr ndarray::FourierTransform< T, N >::_x

private

Definition at line 147 of file FourierTransform.h.

---

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

• /home/lsstsw/stack/Linux64/ndarray/11.0.rc2+1/include/ndarray/fft/FourierTransform.h
• /home/lsstsw/stack/Linux64/ndarray/11.0.rc2+1/include/ndarray/fft/FourierTransform.cc