Package Spectrogram

Class WindowFunction

java.lang.Object

Spectrogram.WindowFunction

public class WindowFunction
extends Object

Window function for use with FFT.

Author:

Douglas Gillespie

Field Summary

Fields

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

Constructor Summary

Constructors

Constructor	Description
WindowFunction()

Method Summary

Modifier and Type	Method	Description
static double[]	bartlett(int length)
static double[]	blackman(int length)
static double[]	blackmanharris(int length)
static 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

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

Field Details

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 Details

WindowFunction

public WindowFunction()

Method Details

getNames

public static 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);