hann

Hann (Hanning) window

Syntax

w = hann(L)

w = hann(L,sflag)

w = hann(___,typeName)

Description

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.

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

Examples

Hann Window

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

L = 64;
wvtool(hann(L))

Input Arguments

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.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

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

w — Hann window

column vector

Hann window, returned as a column vector.

Algorithms

The following equation generates the coefficients of a Hann window:

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

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.

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

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.