hann

Hann (Hanning) window

Syntax

w = hann(L)
w = hann(L,sflag)

Description

example

w = hann(L) returns an L-point symmetric Hann window.
w = hann(L,sflag) returns a Hann window using the window sampling specified by sflag.

Examples

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Create a 64-point Hann window. Display the result using wvtool.

L = 64; wvtool(hann(L))

Input Arguments

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Window length, specified as a positive integer.

Data Types: single | double

Window sampling, specified as one of the following:

• 'symmetric' — Use this option when using windows for filter design.

• 'periodic' — This option is useful for spectral analysis because it enables a windowed signal to have the perfect periodic extension implicit in the discrete Fourier transform. When 'periodic' is specified, hann computes a window of length L + 1 and returns the first L points.

Output Arguments

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Hann window, returned as a column vector.

Algorithms

The following equation generates the coefficients of a Hann window:

$w\left(n\right)=\begin{array}{cc}0.5\left(1-\mathrm{cos}\left(2\pi \frac{n}{N}\right)\right),& 0\le n\le N\end{array}.$

The window length L = N + 1.

References

[1] Oppenheim, Alan V., Ronald W. Schafer, and John R. Buck. Discrete-Time Signal Processing. Upper Saddle River, NJ: Prentice Hall, 1999.

Version History

Introduced before R2006a