Engee documentation

blackmanharris

The minimum four—term Blackman-Harris window.

Library

EngeeDSP

Syntax

Function call

  • w = blackmanharris(L) — returns L-a point symmetric four—membered Blackman-Harris window.

  • w = blackmanharris(L,sflag) — returns the Blackman—Harris window using the window selection specified by the argument sflag.

  • w = blackmanharris(___,typeName) — indicates the possibility of returning the window w with single or double precision.

Arguments

Input arguments

# L — window length

+ a positive integer

Details

The window length, set as a positive integer.

If you ask L as a non-integer number, the function will round it to the nearest integer value.
Типы данных

Float32, Float64, Int8, Int16, Int32, Int64, UInt8, UInt16, UInt32, UInt64

# sflag — window selection

+ "symmetric" (by default) | "periodic"

Details

The window selection method, set as follows:

  • "symmetric" — use this value when using windows to design filters.;

  • "periodic" — use this value when using windows for spectral analysis. When selecting a value "periodic", function blackmanharris calculates the window length L + 1 and returns the first L points. The missing endpoint is the beginning of the next period of periodic expansion of the sequence. Therefore, the sequence satisfies the assumption of the periodicity of the discrete Fourier transform.

Типы данных

String

# typeName — type of output data

+ Float64 (by default) | Float32

Details

The type of output data (class) specified in one of the following ways:

  • Float64 — use this value to return the output data. w with double precision.

  • Float32 — use this value to return the output data. w with single precision.

Типы данных

DataType

Output arguments

# w — The Blackman—Harris window

+ column vector

Details

The Blackman—Harris window, returned as a column vector.

Algorithms

The equation for a symmetric four—term Blackman-Harris window of length it has the form

The equation for a periodic four—term Blackman-Harris window of length it has the form

The periodic window is - periodic.

Ratio Meaning

0.35875

0.48829

0.14128

0.01168

Literature

  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.