Facemorph
Class Complex

java.lang.Object
  Facemorph.Complex

public class Complex
extends java.lang.Object

Basic complex number class

Field Summary

double	x The real component
double	y The imaginary component

Constructor Summary

Complex(double a, double b)
Constructor for complex number

Method Summary

Complex	add(Complex z) Add z to this and return the result as a new complex number
Complex	conjugate() Conjugate the complex number
Complex	copy() Returns a new copy of this complex number
Complex	divide(Complex z) Multiply this by z (result = this*z) and return the result as a new complex number
Complex	dotProduct(Complex z) Returns the complex dot product of this with z
static Complex	exp(Complex val) Calculate complex exponential
static Complex[]	fft1d(Complex[] data, boolean inverse) 1D FFT
static void	fft1d(Complex[] data, Complex[] fft, int N, int step, int start, int out, boolean inverse) FFT using Danielson-Lancoz lemma to make O(NlogN)
static Complex[]	fftNd(Complex[] data, int[] dim, boolean inverse) Multidimensional FFT, note input data is destroyed by running this and the answer will end up in data, and is also returned
static Complex[]	ft1d(Complex[] data, boolean inverse) Slow direct calculation of fourier transform.
double	magnitude() calculate the magnitude of this complex number
double	magnitudeSquared() calculate the magnitude of this complex number
static void	main(java.lang.String[] args) Main method used for testing
Complex	multiply(Complex z) Multiply this by z (result = this*z) and return the result as a new complex number
Complex	subtract(Complex z) Add z to this and return the result as a new complex number
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

x

public double x

The real component

y

public double y

The imaginary component

Constructor Detail

Complex

public Complex(double a,
               double b)

Constructor for complex number

Parameters:

a - real part

b - imaginary part

Method Detail

magnitude

public double magnitude()

calculate the magnitude of this complex number

Returns:

returns the magnitude of the complex number

conjugate

public Complex conjugate()

Conjugate the complex number

Returns:

returns the complex conjugate of this

magnitudeSquared

public double magnitudeSquared()

calculate the magnitude of this complex number

Returns:

returns the magnitude of the complex number

exp

public static Complex exp(Complex val)

Calculate complex exponential

Parameters:

val - the complex value to exponentiate

Returns:

the exponential function result exp(real)(cos(image)+isin(imag))

ft1d

public static Complex[] ft1d(Complex[] data,
                             boolean inverse)

Slow direct calculation of fourier transform. Used to test FFT

Parameters:

data - inptu data vector

inverse - used to perform the inverse FT

Returns:

returns the fourier transform of the dta

fft1d

public static void fft1d(Complex[] data,
                         Complex[] fft,
                         int N,
                         int step,
                         int start,
                         int out,
                         boolean inverse)

FFT using Danielson-Lancoz lemma to make O(NlogN)

Parameters:

data - input data array

fft - outout data array

N - length of portion of data to transform

step - step size along input vector

start - start point to read from

out - start point to write to

inverse - true for inverse FFT

fft1d

public static Complex[] fft1d(Complex[] data,
                              boolean inverse)

1D FFT

Parameters:

data - the data to perform the FFT on

inverse - boolean indicates if inverse FFT is needed

Returns:

return the FFT of the input data

fftNd

public static Complex[] fftNd(Complex[] data,
                              int[] dim,
                              boolean inverse)

Multidimensional FFT, note input data is destroyed by running this and the answer will end up in data, and is also returned

Parameters:

data - the input data to transform

dim - the size of each dimension

inverse - true for inverse transform

Returns:

returns the Complex array representing the FFT of the input data

main

public static void main(java.lang.String[] args)

Main method used for testing

Parameters:

args - args not used

multiply

public Complex multiply(Complex z)

Multiply this by z (result = this*z) and return the result as a new complex number

Parameters:

z - the number to multiply by this

Returns:

returns the this*z

divide

public Complex divide(Complex z)

Multiply this by z (result = this*z) and return the result as a new complex number

Parameters:

z - the number to multiply by this

Returns:

returns the this*z

add

public Complex add(Complex z)

Add z to this and return the result as a new complex number

Parameters:

z - the number to add

Returns:

returns this+z

copy

public Complex copy()

Returns a new copy of this complex number

Returns:

returns the copy

subtract

public Complex subtract(Complex z)

Add z to this and return the result as a new complex number

Parameters:

z - the number to add

Returns:

returns this+z

dotProduct

public Complex dotProduct(Complex z)

Returns the complex dot product of this with z

Parameters:

z - the number to dot product with

Returns:

returns the result of the dot product

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object