bijnum
Class BIJfft

java.lang.Object
  bijnum.BIJfft

public class BIJfft
extends java.lang.Object

This class implements a one-dimensional real->complex fast fourier transform Copyright (c) 1999-2004, Michael Abramoff. All rights reserved.

Constructor Summary

BIJfft(double[] dx)
Set up a BIJfft a matrix x of length power of 2.

BIJfft(float[] x)
Set up a BIJfft a matrix x of length power of 2.

Method Summary

float[]	compute(float[] x) Compute the 1-D Fast fourier transform for x.
float[][]	compute2(float[] x)
static double[]	extend(double[] x)
static double[]	extend(float[] x)
double[]	mag() Compute power spectrum of FFT 1-D.
static void	testsin(float[] wave)

Methods inherited from class java.lang.Object

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

Constructor Detail

BIJfft

public BIJfft(float[] x)

Set up a BIJfft a matrix x of length power of 2.

Parameters:

x - the real array for which you will compute the 1-D FFT.

BIJfft

public BIJfft(double[] dx)

Set up a BIJfft a matrix x of length power of 2.

Parameters:

x - the real array for which you will compute the 1-D FFT.

Method Detail

compute

public float[] compute(float[] x)

Compute the 1-D Fast fourier transform for x. x must have the same length as BIJfft was initialized with to make sure all tables are still valid.

Parameters:

a - vector x (power 2 length)

Returns:

the power spectrum as a float[].

mag

public final double[] mag()

Compute power spectrum of FFT 1-D. Similar implementation.

testsin

public static void testsin(float[] wave)

compute2

public final float[][] compute2(float[] x)

extend

public static double[] extend(double[] x)

extend

public static double[] extend(float[] x)