hann

Hann (Hanning) window

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Syntax

w = hann(L)

w = hann(L,sflag)

w = hann(___,typeName)

Description

w = hann(L) returns an L-point symmetric Hann window.

example

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

w = hann(___,typeName) specifies the option to return the window w with single or double precision.

Examples

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Hann Window

Open Live Script

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

L = 64;
wvtool(hann(L))

$Figure Window Visualization Tool contains 2 axes objects and other objects of type uimenu, uitoolbar, uipanel. Axes object 1 with title Time domain, xlabel Samples, ylabel Amplitude contains an object of type line. Axes object 2 with title Frequency domain, xlabel Normalized Frequency (\times\pi rad/sample), ylabel Magnitude (dB) contains an object of type line.$

Input Arguments

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`L` — Window length
positive integer

Window length, specified as a positive integer.

Note

If you specify L as noninteger, the function rounds it to the nearest integer value.

`sflag` — Window sampling
`"symmetric"` (default) | `"periodic"`

Window sampling method, specified as:

"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, the function computes a window of length L + 1 and returns the first L points.

Data Types: char | string

`typeName` — Output data type
`"double"` (default) | `"single"`

Since R2024b

Output data type (class), specified as one of these:

"double" — Use this option to return a double-precision output w.
"single" — Use this option to return a single-precision output w.

Data Types: char | string

Output Arguments

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`w` — Hann window
column vector

Hann window, returned as a column vector.

Algorithms

The following equation generates the coefficients of a Hann window:

$w (n) = \begin{matrix} 0.5 (1 - \cos (2 π \frac{n}{N})), & 0 \leq n \leq N \end{matrix} .$

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.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

GPU Code Generation
Generate CUDA® code for NVIDIA® GPUs using GPU Coder™.

Version History

Introduced before R2006a

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R2024b: Generate Single-Precision Outputs

The hann function supports single-precision outputs.

R2024a: `hann` supports GPU code generation

The hann function supports code generation for graphical processing units (GPUs). You must have MATLAB^® Coder™ and GPU Coder™ to generate CUDA^® code.

hann

Syntax

Description