org.javaseis.fft
Class SeisFft

java.lang.Object
  org.javaseis.fft.SeisFft

All Implemented Interfaces:

IFFT

public class SeisFft
extends java.lang.Object
implements IFFT

Nested Class Summary

static class	SeisFft.Scale
static class	SeisFft.Type

Field Summary

protected float[]	_cy
protected FftComplex	_fftCplx
protected FftReal	_fftReal
protected int	_lendata
protected int	_lenfft
protected int	_lentran
protected IFFT.Scale	_scale
protected float	_scaleForward
protected float	_scaleInverse
protected int	_signForward
protected int	_signInverse
protected IFFT.Type	_type
protected float[]	_wk

Constructor Summary

SeisFft()
Default constructor for an empty transform

SeisFft(int length)
Forward transform for real data with default padding, type, scaling, and sign

SeisFft(int length, float padPercent)
Forward transform for real data with specified length padding in percent

SeisFft(int length, float padPercent, IFFT.Type type)
Forward transform for real data specifying length, padding, and transform type

SeisFft(int length, float padPercent, IFFT.Type type, int isign)
Forward transform for real data specifying length, padding, transform type, and sign

SeisFft(int length, float padPercent, IFFT.Type type, int isign, IFFT.Scale scale)
Forward transform for real data specifying length, padding, transform type, sign, and scale

Method Summary

void	complexForward(float[] cx) Perform an in-place complex-to-complex forward transform
void	complexForward(float[] cx, float[] cy)
void	complexForward(float[] cx, int offset)
void	complexForward(float[] cx, int xoff, float[] cy, int yoff)
void	complexInverse(float[] cy) Perform an in-place complex-to-complex inverse transform
void	complexInverse(float[] cy, float[] cx)
void	complexInverse(float[] cy, int offset)
void	complexInverse(float[] cy, int yoff, float[] cx, int xoff)
void	complexToReal(float[] cy) Perform an in-place complex-to-real inverse transform
void	complexToReal(float[] cy, float[] rx)
void	complexToReal(float[] cy, int offset)
void	complexToReal(float[] cy, int yoff, float[] rx, int xoff)
int	getArrayLength() Return the length of the transform array in 32 bit words (floats)
int	getLength() Return the transform length
static void	main(java.lang.String[] args)
void	realToComplex(float[] rx) Perform an in-place real to complex forward transform
void	realToComplex(float[] rx, float[] cy) Out-of-place transforms that do not modify the input data
void	realToComplex(float[] rx, int offset) In place transforms with optional offset
void	realToComplex(float[] rx, int xoff, float[] cy, int yoff) Out-of-place transforms that do not modify the input data
void	setFftParms(int length, IFFT.Type type, IFFT.Scale scale, float padPercent, int forwardSign) Set transform parameters

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

_cy

protected float[] _cy

_fftCplx

protected FftComplex _fftCplx

_fftReal

protected FftReal _fftReal

_lendata

protected int _lendata

_lenfft

protected int _lenfft

_lentran

protected int _lentran

_scale

protected IFFT.Scale _scale

_scaleForward

protected float _scaleForward

_scaleInverse

protected float _scaleInverse

_signForward

protected int _signForward

_signInverse

protected int _signInverse

_type

protected IFFT.Type _type

_wk

protected float[] _wk

Constructor Detail

SeisFft

public SeisFft()

Default constructor for an empty transform

SeisFft

public SeisFft(int length)

Forward transform for real data with default padding, type, scaling, and sign

Parameters:

length - length of the input data to be transformed

SeisFft

public SeisFft(int length,
               float padPercent)

Forward transform for real data with specified length padding in percent

Parameters:

length - length of the input data to be transformed

padPercent - requested zero padding as a percentage of the input length

SeisFft

public SeisFft(int length,
               float padPercent,
               IFFT.Type type)

Forward transform for real data specifying length, padding, and transform type

Parameters:

length - length of the input data to be transformed

padPercent - requested zero padding as a percentage of the input length

type - transform type from the enum SeisFft.Type.REAL or SeisFft.Type.COMPLEX

SeisFft

public SeisFft(int length,
               float padPercent,
               IFFT.Type type,
               int isign)

Forward transform for real data specifying length, padding, transform type, and sign

Parameters:

length - length of the input data to be transformed

padPercent - requested zero padding as a percentage of the input length

type - transform type from the enum SeisFft.Type.REAL or SeisFft.Type.COMPLEX

isign - forward transform sign, -1 or +1

SeisFft

public SeisFft(int length,
               float padPercent,
               IFFT.Type type,
               int isign,
               IFFT.Scale scale)

Forward transform for real data specifying length, padding, transform type, sign, and scale

Parameters:

length - length of the input data to be transformed

padPercent - requested zero padding as a percentage of the input length

type - transform type from the enum SeisFft.Type.REAL or SeisFft.Type.COMPLEX

isign - forward transform sign, -1 or +1

scale - transform scaling from the enum SeisFft.Scale.NONE, INVERSE, or SYMMETRIC

Method Detail

complexForward

public void complexForward(float[] cx)

Perform an in-place complex-to-complex forward transform

Specified by:

complexForward in interface IFFT

Parameters:

cx - input complex data, output complex forward transform

complexForward

public void complexForward(float[] cx,
                           float[] cy)

Specified by:

complexForward in interface IFFT

complexForward

public void complexForward(float[] cx,
                           int offset)

Specified by:

complexForward in interface IFFT

complexForward

public void complexForward(float[] cx,
                           int xoff,
                           float[] cy,
                           int yoff)

Specified by:

complexForward in interface IFFT

complexInverse

public void complexInverse(float[] cy)

Perform an in-place complex-to-complex inverse transform

Specified by:

complexInverse in interface IFFT

Parameters:

cy - input complex transform, output complex inverse transform

complexInverse

public void complexInverse(float[] cy,
                           float[] cx)

Specified by:

complexInverse in interface IFFT

complexInverse

public void complexInverse(float[] cy,
                           int offset)

Specified by:

complexInverse in interface IFFT

complexInverse

public void complexInverse(float[] cy,
                           int yoff,
                           float[] cx,
                           int xoff)

Specified by:

complexInverse in interface IFFT

complexToReal

public void complexToReal(float[] cy)

Perform an in-place complex-to-real inverse transform

Specified by:

complexToReal in interface IFFT

Parameters:

cy - input complex Fourier transform, output real inverse Fourier transform

complexToReal

public void complexToReal(float[] cy,
                          float[] rx)

Specified by:

complexToReal in interface IFFT

complexToReal

public void complexToReal(float[] cy,
                          int offset)

Specified by:

complexToReal in interface IFFT

complexToReal

public void complexToReal(float[] cy,
                          int yoff,
                          float[] rx,
                          int xoff)

Specified by:

complexToReal in interface IFFT

getArrayLength

public int getArrayLength()

Return the length of the transform array in 32 bit words (floats)

Specified by:

getArrayLength in interface IFFT

Returns:

transform array length

getLength

public int getLength()

Return the transform length

Specified by:

getLength in interface IFFT

Returns:

transform length

main

public static void main(java.lang.String[] args)

Parameters:

args -

realToComplex

public void realToComplex(float[] rx)

Perform an in-place real to complex forward transform

Specified by:

realToComplex in interface IFFT

Parameters:

rx - input real data to be transformed, output complex Fourier transform

realToComplex

public void realToComplex(float[] rx,
                          float[] cy)

Out-of-place transforms that do not modify the input data

Specified by:

realToComplex in interface IFFT

Parameters:

a - input array to be transformed

b - output array containing transform

realToComplex

public void realToComplex(float[] rx,
                          int offset)

In place transforms with optional offset

Specified by:

realToComplex in interface IFFT

Parameters:

a - input array to be transformed

offset - starting index for transform within the array

realToComplex

public void realToComplex(float[] rx,
                          int xoff,
                          float[] cy,
                          int yoff)

Out-of-place transforms that do not modify the input data

Specified by:

realToComplex in interface IFFT

Parameters:

a - input array to be transformed

aindex - start index of the data in the input array

b - output array containing transform

bindex - start index for placing the output data

setFftParms

public void setFftParms(int length,
                        IFFT.Type type,
                        IFFT.Scale scale,
                        float padPercent,
                        int forwardSign)

Set transform parameters

Specified by:

setFftParms in interface IFFT

Parameters:

length - length of the input data to be transformed

type - transform type from the enum SeisFft.Type.REAL or SeisFft.Type.COMPLEX

scale - transform scaling from the enum SeisFft.Scale.NONE, INVERSE, or SYMMETRIC

padPercent - requested zero padding as a percentage of the input length

isign - forward transform sign, -1 or +1