Pscf::Prdc::Cuda::FFT< D > Class Template Reference

Fourier transform wrapper for real or complex data. More...

#include <FFT.h>

Public Member Functions
	FFT ()
	Default constructor.
virtual	~FFT ()
	Destructor.
void	setup (IntVec< D > const &meshDimensions)
	Setup grid dimensions, plans and work space.
void	forwardTransform (RField< D > const &rField, RFieldDft< D > &kField) const
	Compute forward (real-to-complex) discrete Fourier transform.
void	inverseTransformUnsafe (RFieldDft< D > &kField, RField< D > &rField) const
	Compute inverse (complex-to-real) DFT, overwriting the input.
void	inverseTransformSafe (RFieldDft< D > const &kField, RField< D > &rField) const
	Compute inverse (complex-to-real) DFT without overwriting input.
void	forwardTransform (CField< D > const &rField, CField< D > &kField) const
	Compute forward (complex-to-complex) discrete Fourier transform.
void	inverseTransform (CField< D > const &kField, CField< D > &rField) const
	Compute inverse (complex-to-complex) discrete Fourier transform.
const IntVec< D > &	meshDimensions () const
	Return the dimensions of the grid for which this was allocated.
bool	isSetup () const
	Has this FFT object been setup?

Detailed Description

template<int D>
class Pscf::Prdc::Cuda::FFT< D >

Fourier transform wrapper for real or complex data.

Definition at line 21 of file rpg/solvers/Mixture.h.

Constructor & Destructor Documentation

FFT()

template<int D>

Pscf::Prdc::Cuda::FFT< D >::FFT

(

)

Default constructor.

~FFT()

template<int D>

virtual Pscf::Prdc::Cuda::FFT< D >::~FFT ( )

virtual

Destructor.

Member Function Documentation

setup()

template<int D>

void Pscf::Prdc::Cuda::FFT< D >::setup

(

IntVec< D > const &

meshDimensions

)

Setup grid dimensions, plans and work space.

Parameters

meshDimensions

Dimensions of real-space grid.

forwardTransform() [1/2]

template<int D>

void Pscf::Prdc::Cuda::FFT< D >::forwardTransform	(	RField< D > const &	rField,
		RFieldDft< D > &	kField ) const

Compute forward (real-to-complex) discrete Fourier transform.

The resulting complex array is the output of cuFFT's forward transform method scaled by a factor of 1/N (where N is the number of grid points). The scaling ensures that a round-trip Fourier transform (forward + inverse) reproduces the original input array.

This transform is inherently "safe", meaning that the input array will not be modified during the DFT.

Parameters

rField	real values on r-space grid (input, gpu mem)
kField	complex values on k-space grid (output, gpu mem)

inverseTransformUnsafe()

template<int D>

void Pscf::Prdc::Cuda::FFT< D >::inverseTransformUnsafe	(	RFieldDft< D > &	kField,
		RField< D > &	rField ) const

Compute inverse (complex-to-real) DFT, overwriting the input.

The resulting real array is the unaltered output of cuFFT's inverse transform function.

This transform is inherently "unsafe", meaning that the input array will be overwritten during the DFT. Accordingly, the input array kField is not const like it is in all the other transform methods.

Parameters

kField	complex values on k-space grid (input, gpu mem)
rField	real values on r-space grid (output, gpu mem)

inverseTransformSafe()

template<int D>

void Pscf::Prdc::Cuda::FFT< D >::inverseTransformSafe	(	RFieldDft< D > const &	kField,
		RField< D > &	rField ) const

Compute inverse (complex-to-real) DFT without overwriting input.

This method makes a copy of the input kField array before performing the DFT, thus preserving the input.

Parameters

kField	complex values on k-space grid (input, gpu mem)
rField	real values on r-space grid (output, gpu mem)

forwardTransform() [2/2]

template<int D>

void Pscf::Prdc::Cuda::FFT< D >::forwardTransform	(	CField< D > const &	rField,
		CField< D > &	kField ) const

Compute forward (complex-to-complex) discrete Fourier transform.

The resulting complex array is the output of cuFFT's forward transform method scaled by a factor of 1/N (where N is the number of grid points). The scaling ensures that a round-trip Fourier transform (forward + inverse) reproduces the original input array.

This transform is inherently "safe", meaning that the input array will not be modified during the DFT.

Note that, in this transform, the k-space grid is the same size as the r-space grid, which differs from the real-to-complex transform.

Parameters

rField	complex values on r-space grid (input, gpu mem)
kField	complex values on k-space grid (output, gpu mem)

inverseTransform()

template<int D>

void Pscf::Prdc::Cuda::FFT< D >::inverseTransform	(	CField< D > const &	kField,
		CField< D > &	rField ) const

Compute inverse (complex-to-complex) discrete Fourier transform.

The resulting complex array is the unaltered output of cuFFT's inverse transform function.

This transform is inherently "safe", meaning that the input array will not be modified during the DFT.

Note that, in this transform, the k-space grid is the same size as the r-space grid, which differs from the real-to-complex transform.

Parameters

kField	complex values on k-space grid (input, gpu mem)
rField	complex values on r-space grid (output, gpu mem)

meshDimensions()

template<int D>

const IntVec< D > & Pscf::Prdc::Cuda::FFT< D >::meshDimensions

(

)

const

Return the dimensions of the grid for which this was allocated.

isSetup()

template<int D>

bool Pscf::Prdc::Cuda::FFT< D >::isSetup

(

)

const

Has this FFT object been setup?

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

• cuda/FFT.h
• rpg/solvers/Mixture.h