Programmer Guide/SPU Reference/WINDOW

WINDOW - signal window function

Usage:

WINDOW x type c mode

Inputs:

Name	Description
x	window length or frame buffer
type	window function type
c	window function parameter
mode	processing mode

Outputs:

Name	Description
y	window function or windowed signal
k	window scaling factor

Function:

This atom implements a set of well known signal windowing functions. It can be used to compute a windowing function (which should be applied to the signal in a later processing step) or to multiply the signal with a windowing function directly.

The output k is set to a (average) scaling factor that can be used to align the energy of the input signal x and the weighted signal y. To compute the scaling factor, one frame of white noise is used as a test signal. The input mode determines whether the window function should be multiplied with the energy-scaling-factor k (mode=1) or not (mode=0).

Window computation, controlled by data input x

type of input x	description
number	The value of x (>2) is used as window length. The selected window function is computed and stored in the output vector y.
vector	The input x is used as signal vector (length >2) and multiplied with the selected window function. The weighted signal is stored in the output y.

Windowing function, selected by type (function type) and c (parameter).

value of type	value of c	window function / comment
0 or RECTANGLE	-	rectangle window
1 or HANNING	-	Hanning window
2 or HAMMING	-	Hamming window
3 or BLACKMAN	-	Blackman-Harris window
4 or KAISER	exponent (>0)	Kaiser-Bessel window
5 or BARTLETT	-	Bartlett (triangle) window

See also

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