com.softsynth.math

Class FourierMath

java.lang.Object

com.softsynth.math.FourierMath

public class FourierMath
extends java.lang.Object

Constructor Summary

Constructors

Constructor and Description
FourierMath()

Method Summary

Modifier and Type	Method and Description
static void	calculateMagnitudes(double[] ar, double[] ai, double[] magnitudes) Calculate the amplitude of the sine wave associated with each bin of a complex FFT result.
static void	calculateMagnitudes(float[] ar, float[] ai, float[] magnitudes) Calculate the amplitude of the sine wave associated with each bin of a complex FFT result.
static void	fft(int n, double[] ar, double[] ai) Calculate an FFT in place, modifying the input arrays.
static void	ifft(int n, double[] ar, double[] ai) Calculate an inverse FFT in place, modifying the input arrays.
static int	numBits(int powerOf2) Calculate log2(n)
static void	transform(int sign, int n, double[] ar, double[] ai)
static void	transform(int sign, int n, float[] ar, float[] ai)

Methods inherited from class java.lang.Object

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

Constructor Detail

FourierMath

public FourierMath()

Method Detail

calculateMagnitudes

public static void calculateMagnitudes(double[] ar,
                                       double[] ai,
                                       double[] magnitudes)

Calculate the amplitude of the sine wave associated with each bin of a complex FFT result.

Parameters:

ar -

ai -

magnitudes -

calculateMagnitudes

public static void calculateMagnitudes(float[] ar,
                                       float[] ai,
                                       float[] magnitudes)

Calculate the amplitude of the sine wave associated with each bin of a complex FFT result.

Parameters:

ar -

ai -

magnitudes -

transform

public static void transform(int sign,
                             int n,
                             double[] ar,
                             double[] ai)

transform

public static void transform(int sign,
                             int n,
                             float[] ar,
                             float[] ai)

numBits

public static int numBits(int powerOf2)

Calculate log2(n)

Parameters:

powerOf2 - must be a power of two, for example 512 or 1024

Returns:

for example, 9 for an input value of 512

fft

public static void fft(int n,
                       double[] ar,
                       double[] ai)

Calculate an FFT in place, modifying the input arrays.

Parameters:

n -

ar -

ai -

ifft

public static void ifft(int n,
                        double[] ar,
                        double[] ai)

Calculate an inverse FFT in place, modifying the input arrays.

Parameters:

n -

ar -

ai -