The OpenFOAM Foundation
fft Class Reference

Fast fourier transform derived from the Numerical Recipes in C routine. More...

## Public Types

enum  transformDirection { FORWARD_TRANSFORM = 1 , REVERSE_TRANSFORM = -1 }

## Static Public Member Functions

static void transform (complexField &field, const labelList &nn, transformDirection fftDirection)

static tmp< complexFieldforwardTransform (const tmp< complexField > &field, const labelList &nn)

static tmp< complexFieldreverseTransform (const tmp< complexField > &field, const labelList &nn)

static tmp< complexVectorFieldforwardTransform (const tmp< complexVectorField > &field, const labelList &nn)

static tmp< complexVectorFieldreverseTransform (const tmp< complexVectorField > &field, const labelList &nn)

## Detailed Description

Fast fourier transform derived from the Numerical Recipes in C routine.

The complex transform field is returned in the field supplied. The direction of transform is supplied as an argument (1 = forward, -1 = reverse). The dimensionality and organisation of the array of values in space is supplied in the nn indexing array.

Source files

Definition at line 51 of file fft.H.

## ◆ transformDirection

 enum transformDirection
Enumerator
FORWARD_TRANSFORM
REVERSE_TRANSFORM

Definition at line 56 of file fft.H.

## ◆ transform()

 void transform ( complexField & field, const labelList & nn, transformDirection fftDirection )
static

Definition at line 41 of file fft.C.

Referenced by fft::forwardTransform(), and fft::reverseTransform().

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## ◆ forwardTransform() [1/2]

 tmp< complexField > forwardTransform ( const tmp< complexField > & field, const labelList & nn )
static

Definition at line 186 of file fft.C.

References tmp< T >::clear(), fft::FORWARD_TRANSFORM, tmp< T >::ref(), and fft::transform().

Referenced by fft::forwardTransform(), and Foam::writeEk().

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## ◆ reverseTransform() [1/2]

 tmp< complexField > reverseTransform ( const tmp< complexField > & field, const labelList & nn )
static

Definition at line 202 of file fft.C.

References tmp< T >::clear(), tmp< T >::ref(), fft::REVERSE_TRANSFORM, and fft::transform().

Referenced by main(), noiseFFT::Pf(), fft::reverseTransform(), and turbGen::U().

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## ◆ forwardTransform() [2/2]

 tmp< complexVectorField > forwardTransform ( const tmp< complexVectorField > & field, const labelList & nn )
static

Definition at line 218 of file fft.C.

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## ◆ reverseTransform() [2/2]

 tmp< complexVectorField > reverseTransform ( const tmp< complexVectorField > & field, const labelList & nn )
static

Definition at line 247 of file fft.C.

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The documentation for this class was generated from the following files:
• src/randomProcesses/fft/fft.H
• src/randomProcesses/fft/fft.C