math.fourierTransforms.r2
Class FFT1dDouble

java.lang.Object
  math.fourierTransforms.r2.FFT1dDouble

public class FFT1dDouble
extends java.lang.Object

Works. Automatically scales ouput in ifft. A 1D FFT for integral power of two FFTs

Constructor Summary

FFT1dDouble()

Method Summary

void	computeBackwardFFT(double[] in_r, double[] in_i)
void	computeForwardFFT(double[] in_r, double[] in_i)
void	fft(double[] _realPart, double[] _imaginaryPart) FFT engine.
double[]	getImaginaryData()
static double	getMagnitude(double r, double imag) Compute the sum of the squares of a complex number
static int	getMaxPSDLocation(double[] realPart, double[] imaginaryPart) get the location of the maximum partial
double[]	getPSD()
static double[]	getPsd(double[] audioWaveForm)
static double[]	getPSD(double[] in_r, double[] in_i) Compute the power spectral density of the input arrays
double[]	getRealData()
static OscopePanel	getSpectrumPanel(double[] audioWaveForm)
static void	main(java.lang.String[] args)
static void	print(java.lang.Object[] o)
static void	showSpectrumAnalyzer() A way to visually test the 1D FFT on a small amount of data.
void	swap(int i, int numBits) 1D FFT utility functions.
static void	synthesizeRamp(double[] realPart, double[] imaginaryPart) Destroy the input data with a linear ramp.
static void	testFFT() Test the DFT using a small number of samples.
static void	testFFT2()
void	timeFFT(int n)
void	visuallyTest()
static void	window(double[] r, double[] w)

Methods inherited from class java.lang.Object

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

Constructor Detail

FFT1dDouble

public FFT1dDouble()

Method Detail

showSpectrumAnalyzer

public static void showSpectrumAnalyzer()

A way to visually test the 1D FFT on a small amount of data.

getSpectrumPanel

public static OscopePanel getSpectrumPanel(double[] audioWaveForm)

getPsd

public static double[] getPsd(double[] audioWaveForm)

visuallyTest

public void visuallyTest()

timeFFT

public void timeFFT(int n)

print

public static void print(java.lang.Object[] o)

synthesizeRamp

public static void synthesizeRamp(double[] realPart,
                                  double[] imaginaryPart)

Destroy the input data with a linear ramp.

Parameters:

realPart - input datas real component

imaginaryPart - input datas' imaginary component.

window

public static void window(double[] r,
                          double[] w)

swap

public void swap(int i,
                 int numBits)

1D FFT utility functions.

getMaxPSDLocation

public static int getMaxPSDLocation(double[] realPart,
                                    double[] imaginaryPart)

get the location of the maximum partial

Parameters:

realPart -

imaginaryPart -

Returns:

location of max(realPart[i],imaginaryPart[i])

getMagnitude

public static double getMagnitude(double r,
                                  double imag)

Compute the sum of the squares of a complex number

Parameters:

r - real part

imag - imaginary part

Returns:

r*r + imag * imag.

computeForwardFFT

public void computeForwardFFT(double[] in_r,
                              double[] in_i)

computeBackwardFFT

public void computeBackwardFFT(double[] in_r,
                               double[] in_i)

fft

public void fft(double[] _realPart,
                double[] _imaginaryPart)

FFT engine.

getRealData

public double[] getRealData()

Returns:

gets the real component from FFT.

getImaginaryData

public double[] getImaginaryData()

Returns:

gets the imaginary component from FFT.

getPSD

public double[] getPSD()

Returns:

Power Spectral Density of the internal data

getPSD

public static double[] getPSD(double[] in_r,
                              double[] in_i)

Compute the power spectral density of the input arrays

Parameters:

in_r - real part of an fft

in_i - imaginary part of an fft

Returns:

the psd.

testFFT2

public static void testFFT2()

testFFT

public static void testFFT()

Test the DFT using a small number of samples. This is an O(N**2) algorithm.

main

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