Class FFT

java.lang.Object
math.FFT
public class FFT extends Object
Computes FFT's of complex, double precision data where n is an integer power of 2. This appears to be slower than the Radix2 method, but the code is smaller and simpler, and it requires no extra storage. <P>
Author:
Bruce R. Miller bruce.miller@nist.gov,, Derived from GSL (Gnu Scientific Library),, GSL's FFT Code by Brian Gough bjg@vvv.lanl.gov

  • Constructor Summary

    Constructors
    Constructor
    Description
    FFT()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    protected static void
    bitreverse(double[] data)
     
    static void
    inverse(double[] data)
    Compute Inverse Fast Fourier Transform of (complex) data, in place.
    protected static int
    log2(int n)
     
    static final double
    num_flops(int N)
     
    static double
    test(double[] data)
    Accuracy check on FFT of data.
    static void
    transform(double[] data)
    Compute Fast Fourier Transform of (complex) data, in place.
    protected static void
    transform_internal(double[] data, int direction)
     

    Methods inherited from class Object

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

  • Constructor Details

    • FFT

      public FFT()

  • Method Details

    • num_flops

      public static final double num_flops(int N)

    • transform

      public static void transform(double[] data)
      Compute Fast Fourier Transform of (complex) data, in place.

    • inverse

      public static void inverse(double[] data)
      Compute Inverse Fast Fourier Transform of (complex) data, in place.

    • test

      public static double test(double[] data)
      Accuracy check on FFT of data. Make a copy of data, Compute the FFT, then the inverse and compare to the original. Returns the rms difference.

    • log2

      protected static int log2(int n)

    • transform_internal

      protected static void transform_internal(double[] data, int direction)

    • bitreverse

      protected static void bitreverse(double[] data)