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" — Use this option when using windows for spectral analysis. When you specify "periodic", hann computes a window of length L + 1 and returns the first L points. The missing endpoint is the beginning of the next period of the periodic extension of the sequence. Therefore, the sequence satisfies the periodicity assumption of the discrete Fourier transform.

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.