java.lang.Object
- java.lang.Thread
- - gov.nih.mipav.model.algorithms.AlgorithmBase
  - - gov.nih.mipav.model.algorithms.filters.FFTUtility

All Implemented Interfaces:

java.awt.event.ActionListener, java.awt.event.WindowListener, java.lang.Runnable, java.util.EventListener
```
public class FFTUtility
extends AlgorithmBase
```
This FFT should only be used when it is necessary to perform a N-dimensional FFT on non-power of two data without adding padding. Otherwise, developers should use AlgorithmFFT (which has multithreading/jocl optimizations). For forward transforms arrays a and b originally hold the real and imaginary components of the data, and return the real and imaginary components of the resulting fourier coefficients. The roles reverse for the inverse transform. multivariate data is indexed according to Java indexing conventions in which the last dimension is contiguous in memory, without limit on the number of implied multiple subscripts. the subroutine is called once for each variate. the calls for a multivariate transform may be in any order. n is the dimension of the current variable. If n has more than 15 "factors", FFT terminates with an error message. The smallest number with 16 "factors" is 12,754,584, so this error condition should not occur very often. nspn is the spacing of consecutive data values while indexing the current variable. nseg*n*nspn is the total number of complex data values. The sign of isn determines the sign of the complex exponential, and the magnitude of isn is normally one. isn is -1 for the forward transform and +1 for the inverse transform. The magnitude of isn determines the indexing increment for a & b. If fft is called twice, with opposite signs on isn, an identity transformation is done. Calls can be in either order. The results are scaled by 1/n when the sign of isn is positive. a tri-variate transform with a(n1,n2,n3), b(n1,n2,n3) is computed by FFTUtility fft = new FFTUtility(a,b,n1*n2,n3,1,-1,FFTUtility.FFT); fft.run(); fft = new FFTUtility(a,b,n1,n2,n3,-1,FFTUtility.FFT); fft.run(); fft = new FFTUtility(a,b,1,n1,n2*n3,-1,FFTUtility.FFT); fft.run(); for a single-variate transform, FFTUtility fft = new FFTUtility(a,b,1,n,1,-1,FFTUtility.FFT); fft.run();

See Also:

This class is based on the Fortran/C code for R. C. Singleton's mixed radix FFT algorithm, released under the below license by Mark Olesen on NETLIB (netlib.org). References: R. C. Singleton, An algorithm for computing the mixed radix fast Fourier transform, IEEE Transactions on Audio and Electroacoustics, AU-17, no. 2, June, 1969, pp. 93-103. multivariate complex fourier transform, computed in place using mixed-radix fast fourier transform algorithm. by r. c. singleton, stanford research institute, sept. 1968 Copyright(c)1995,97 Mark Olesen olesen@me.QueensU.CA Queen's Univ at Kingston (Canada) Permission to use, copy, modify, and distribute this software for any purpose without fee is hereby granted, provided that this entire notice is included in all copies of any software which is or includes a copy or modification of this software and in all copies of the supporting documentation for such software. THIS SOFTWARE IS BEING PROVIDED AS IS, WITHOUT ANY EXPRESS OR IMPLIED WARRANTY. IN PARTICULAR, NEITHER THE AUTHOR NOR QUEEN'S UNIVERSITY AT KINGSTON MAKES ANY REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE. All of which is to say that you can do what you like with this source code provided you don't try to sell it as your own and you include an unaltered copy of this message (including the copyright). It is also implicitly understood that bug fixes and improvements should make their way back to the general Internet community so that everyone benefits.

Nested Class Summary
- Nested classes/interfaces inherited from class java.lang.Thread
  java.lang.Thread.State, java.lang.Thread.UncaughtExceptionHandler

Field Summary

Fields
Modifier and Type	Field	Description
`private double[]`	`a`	DOCUMENT ME!
`private double[]`	`b`	DOCUMENT ME!
`static int`	`FFT`	DOCUMENT ME!
`private int`	`functionType`	DOCUMENT ME!
`private int`	`isn`	DOCUMENT ME!
`private int`	`n`	DOCUMENT ME!
`private int`	`nseg`	DOCUMENT ME!
`private int`	`nspn`	DOCUMENT ME!
`static int`	`REALS`	DOCUMENT ME!
`static int`	`REALT`	DOCUMENT ME!
`static int`	`SELF_TEST`	DOCUMENT ME!
`private boolean`	`showProgress`

Fields inherited from class gov.nih.mipav.model.algorithms.AlgorithmBase
destFlag, destImage, image25D, mask, maxProgressValue, minProgressValue, multiThreadingEnabled, nthreads, progress, progressModulus, progressStep, runningInSeparateThread, separable, srcImage, threadStopped

Fields inherited from class java.lang.Thread
MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

Constructors
Constructor	Description
`FFTUtility(double[] a, double[] b, int nseg, int n, int nspn, int isn, int functionType)`	Creates a new FFTUtility object.
`FFTUtility(int functionType)`	This constructor should only be used for functionType == SELF_TEST.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`private void`	`fft()`	DOCUMENT ME!
`void`	`finalize()`	DOCUMENT ME!
`(package private) double[]`	`normal()`	DOCUMENT ME!
`private void`	`reals()`	DOCUMENT ME!
`private void`	`realt()`	DOCUMENT ME!
`(package private) double[]`	`rms(double[] a, double[] b, double[] c, double[] d, int n)`	DOCUMENT ME!
`void`	`runAlgorithm()`	Starts the program.
`private void`	`selfTest()`	DOCUMENT ME!
`void`	`setShowProgress(boolean showProgress)`
`void`	`sortg(double[] a, int n, double[] tag)`	DOCUMENT ME!

Methods inherited from class gov.nih.mipav.model.algorithms.AlgorithmBase
actionPerformed, addListener, addProgressChangeListener, calculateImageSize, calculatePrincipleAxis, computeElapsedTime, computeElapsedTime, convertIntoFloat, delinkProgressToAlgorithm, delinkProgressToAlgorithmMulti, displayError, errorCleanUp, fireProgressStateChanged, fireProgressStateChanged, fireProgressStateChanged, fireProgressStateChanged, fireProgressStateChanged, generateProgressValues, getDestImage, getElapsedTime, getMask, getMaxProgressValue, getMinProgressValue, getNumberOfThreads, getProgress, getProgressChangeListener, getProgressChangeListeners, getProgressModulus, getProgressStep, getProgressValues, getSrcImage, isCompleted, isImage25D, isMultiThreadingEnabled, isRunningInSeparateThread, isThreadStopped, linkProgressToAlgorithm, linkProgressToAlgorithm, makeProgress, notifyListeners, removeListener, removeProgressChangeListener, run, setCompleted, setImage25D, setMask, setMaxProgressValue, setMinProgressValue, setMultiThreadingEnabled, setNumberOfThreads, setProgress, setProgressModulus, setProgressStep, setProgressValues, setProgressValues, setRunningInSeparateThread, setSrcImage, setStartTime, setThreadStopped, startMethod, windowActivated, windowClosed, windowClosing, windowDeactivated, windowDeiconified, windowIconified, windowOpened

Methods inherited from class java.lang.Thread
activeCount, checkAccess, clone, countStackFrames, currentThread, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, onSpinWait, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, suspend, toString, yield

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - FFT
```
public static final int FFT
```
    DOCUMENT ME!
    
    See Also:
    
    Constant Field Values
  - REALS
```
public static final int REALS
```
    DOCUMENT ME!
    
    See Also:
    
    Constant Field Values
  - REALT
```
public static final int REALT
```
    DOCUMENT ME!
    
    See Also:
    
    Constant Field Values
  - SELF_TEST
```
public static final int SELF_TEST
```
    DOCUMENT ME!
    
    See Also:
    
    Constant Field Values
  - a
```
private double[] a
```
    DOCUMENT ME!
  - b
```
private double[] b
```
    DOCUMENT ME!
  - functionType
```
private int functionType
```
    DOCUMENT ME!
  - isn
```
private int isn
```
    DOCUMENT ME!
  - n
```
private int n
```
    DOCUMENT ME!
  - nseg
```
private int nseg
```
    DOCUMENT ME!
  - nspn
```
private int nspn
```
    DOCUMENT ME!
  - showProgress
```
private boolean showProgress
```
- Constructor Detail
  - FFTUtility
```
public FFTUtility(int functionType)
```
    This constructor should only be used for functionType == SELF_TEST.
    
    Parameters:
    
    functionType - DOCUMENT ME!
  - FFTUtility
```
public FFTUtility(double[] a,
                  double[] b,
                  int nseg,
                  int n,
                  int nspn,
                  int isn,
                  int functionType)
```
    Creates a new FFTUtility object.
    
    Parameters:
    
    a - DOCUMENT ME!
    
    b - DOCUMENT ME!
    
    nseg - DOCUMENT ME!
    
    n - DOCUMENT ME!
    
    nspn - DOCUMENT ME!
    
    isn - DOCUMENT ME!
    
    functionType - DOCUMENT ME!
- Method Detail
  - finalize
```
public void finalize()
```
    DOCUMENT ME!
    
    Overrides:
    
    finalize in class AlgorithmBase
  - setShowProgress
```
public void setShowProgress(boolean showProgress)
```
    Parameters:
    
    showProgress -
  - runAlgorithm
```
public void runAlgorithm()
```
    Starts the program.
    
    Specified by:
    
    runAlgorithm in class AlgorithmBase
  - normal
```
double[] normal()
```
    DOCUMENT ME!
    
    Returns:
    
    DOCUMENT ME!
  - rms
```
double[] rms(double[] a,
             double[] b,
             double[] c,
             double[] d,
             int n)
```
    DOCUMENT ME!
    
    Parameters:
    
    a - DOCUMENT ME!
    
    b - DOCUMENT ME!
    
    c - DOCUMENT ME!
    
    d - DOCUMENT ME!
    
    n - DOCUMENT ME!
    
    Returns:
    
    DOCUMENT ME!
  - fft
```
private void fft()
```
    DOCUMENT ME!
  - reals
```
private void reals()
```
    DOCUMENT ME!
  - realt
```
private void realt()
```
    DOCUMENT ME!
  - selfTest
```
private void selfTest()
```
    DOCUMENT ME!
  - sortg
```
public void sortg(double[] a,
                  int n,
                  double[] tag)
```
    DOCUMENT ME!
    
    Parameters:
    
    a - DOCUMENT ME!
    
    n - DOCUMENT ME!
    
    tag - DOCUMENT ME!

Class FFTUtility

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

Field Summary

Fields inherited from class gov.nih.mipav.model.algorithms.AlgorithmBase

Fields inherited from class java.lang.Thread

Constructor Summary

Method Summary

Methods inherited from class gov.nih.mipav.model.algorithms.AlgorithmBase

Methods inherited from class java.lang.Thread

Methods inherited from class java.lang.Object

Field Detail

FFT

REALS

REALT

SELF_TEST

a

b

functionType

isn

n

nseg

nspn

showProgress

Constructor Detail

FFTUtility

FFTUtility

Method Detail

finalize

setShowProgress

runAlgorithm

normal

rms

fft

reals

realt

selfTest

sortg