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blackmanharris

Minimum four-term Blackman-Harris window

Syntax

w = blackmanharris(N)
w = blackmanharris(N,sflag)

Description

example

w = blackmanharris(N) returns an N-point symmetric four-term Blackman-Harris window.

w = blackmanharris(N,sflag) returns a Blackman-Harris window using the window sampling method specified by sflag.

Examples

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Create a 32-point symmetric Blackman-Harris window. Display the result using wvtool.

N = 32;
wvtool(blackmanharris(N))

Input Arguments

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Window length, specified as a positive integer.

Data Types: single | double

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.

Output Arguments

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Blackman-Harris window, returned as a column vector.

Algorithms

The equation for the symmetric four-term Blackman-Harris window of length N is

w(n)=a0a1cos(2πnN1)+a2cos(4πnN1)a3cos(6πnN1),0nN1

The equation for the periodic four-term Blackman-Harris window of length N is

w(n)=a0a1cos2πnN+a2cos4πnNa3cos6πnN,0nN1

The periodic window is N-periodic.

CoefficientValue
a00.35875
a10.48829
a20.14128
a30.01168

References

[1] harris, fredric j. “On the Use of Windows for Harmonic Analysis with the Discrete Fourier Transform.” Proceedings of the IEEE®. Vol. 66, January 1978, pp. 51–83.

Extended Capabilities

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

Introduced before R2006a