flattopwin (Signal Processing Toolbox)

Compute a Flat Top weighted window.

Syntax

w = flattopwin(n)
w = flattopwin(n,sflag)

Description

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.

w = flattopwin(n) returns the n-point symmetric Flat Top window in column vector w.

w = flattopwin(n,sflag) returns the n-point symmetric Flat Top window using sflag window sampling, where sflag is either 'symmetric' or 'periodic'.

Algorithm

Flat top windows are summations of cosines. The coefficients of a flat top window are computed from the following equation

where and elsewhere.

Examples

Create a 64-point, symmetric Flat Top window and view the window using WVTool:

```
w = flattopwin(64); 
wvtool(w);
```

See Also

blackman, hamming, hann

Reference

[1] Gade, Svend and Herlufsen, H., "Use of Weighting Functions in DFT/FFT Analysis (Part I)," Brüel & Kjær, Windows to FFT Analysis (Part I) Technical Review, No. 3, 1987, pp. 19-21.

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