flattopwin function

Flat top window

Return the filter coefficients of a flat top window.

flattopwin(n, method = c("symmetric", "periodic"))

Arguments

• n: Window length, specified as a positive integer.

• method: Character string. Window sampling method, specified as:

  • "symmetric": (Default). 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 n + 1 and returns the first n points.

Returns

Flat top window, returned as a vector.

Details

The Flat Top window is defined by the function:

where w = i/(n-1) for i=0:n-1 for a symmetric window, or w = i/n for i=0:n-1 for a periodic window. The default is symmetric. The returned window is normalized to a peak of 1 at w = 0.5.

Flat top windows have very low passband ripple (< 0.01 dB) and are used primarily for calibration purposes. Their bandwidth is approximately 2.5 times wider than a Hann window.

Examples

ft <- flattopwin(64)
plot (ft, type = "l", xlab = "Samples", ylab =" Amplitude")

Author(s)

Paul Kienzle, pkienzle@users.sf.net .

Conversion to R by Geert van Boxtel, G.J.M.vanBoxtel@gmail.com .