Spectrogram

Class WindowFunction

java.lang.Object

Spectrogram.WindowFunction

public class WindowFunction
extends java.lang.Object

Window function for use with FFT.

Author:

Douglas Gillespie

Field Summary

Fields

Modifier and Type	Field and Description
static int	BARTLETT
static int	BLACKMAN
static int	BLACKMANHARRIS
static int	HAMMING
static int	HANNING
static int	NWINDOWS
static int	RECTANGULAR

Constructor Summary

Constructors

Constructor and Description
WindowFunction()

Method Summary

Methods

Modifier and Type	Method and Description
static double[]	bartlett(int length)
static double[]	blackman(int length)
static double[]	blackmanharris(int length)
static java.lang.String[]	getNames()
static double[]	getWindowFunc(int windowType, int length)
static double	getWindowGain(double[] windowFunction) Calculate the gain of the window function
static double[]	hamming(int length)
static double[]	hann(int length)
static double[]	rectangular(int length)
static double[]	tukey(int length, double a) also known as tapered-cosine, for a=0 becomes rectangular and a=1 becomes hann

Methods inherited from class java.lang.Object

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

Field Detail

RECTANGULAR

public static final int RECTANGULAR

See Also:

Constant Field Values

HAMMING

public static final int HAMMING

See Also:

Constant Field Values

HANNING

public static final int HANNING

See Also:

Constant Field Values

BARTLETT

public static final int BARTLETT

See Also:

Constant Field Values

BLACKMAN

public static final int BLACKMAN

See Also:

Constant Field Values

BLACKMANHARRIS

public static final int BLACKMANHARRIS

See Also:

Constant Field Values

NWINDOWS

public static final int NWINDOWS

See Also:

Constant Field Values

Constructor Detail

WindowFunction

public WindowFunction()

Method Detail

getNames

public static java.lang.String[] getNames()

getWindowFunc

public static double[] getWindowFunc(int windowType,
                     int length)

hamming

public static double[] hamming(int length)

hann

public static double[] hann(int length)

rectangular

public static double[] rectangular(int length)

bartlett

public static double[] bartlett(int length)

blackman

public static double[] blackman(int length)

blackmanharris

public static double[] blackmanharris(int length)

tukey

public static double[] tukey(int length,
             double a)

also known as tapered-cosine, for a=0 becomes rectangular and a=1 becomes hann

Parameters:

length -

Returns:

getWindowGain

public static double getWindowGain(double[] windowFunction)

Calculate the gain of the window function

Parameters:

windowFunction - window function array

Returns:

window rms gain as a factor (NOT dB);