com.meapsoft
Class FFT
java.lang.Object
com.meapsoft.FFT
- public class FFT
- extends java.lang.Object
Utility class to perform a fast fourier transform without
allocating any extra memory.
Constructor Summary |
FFT(int n)
|
Method Summary |
protected static void |
beforeAfter(FFT fft,
double[] re,
double[] im)
|
void |
fft(double[] x,
double[] y)
fft.c
Douglas L. |
double[] |
getWindow()
|
static void |
main(java.lang.String[] args)
|
protected void |
makeWindow()
|
protected static void |
printReIm(double[] re,
double[] im)
|
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
FFT
public FFT(int n)
makeWindow
protected void makeWindow()
getWindow
public double[] getWindow()
fft
public void fft(double[] x,
double[] y)
- fft.c
Douglas L. Jones
University of Illinois at Urbana-Champaign
January 19, 1992
http://cnx.rice.edu/content/m12016/latest/
fft: in-place radix-2 DIT DFT of a complex input
input:
n: length of FFT: must be a power of two
m: n = 2**m
input/output
x: double array of length n with real part of data
y: double array of length n with imag part of data
Permission to copy and use this program is granted
as long as this header is included.
main
public static void main(java.lang.String[] args)
beforeAfter
protected static void beforeAfter(FFT fft,
double[] re,
double[] im)
printReIm
protected static void printReIm(double[] re,
double[] im)