windowing: Windowing functions In signal: Signal Processing

Description

A variety of generally Matlab/Octave compatible filter generation functions, including Bartlett, Blackman, Hamming, Hanning, and triangular.

Usage

 ```1 2 3 4 5 6 7 8``` ```bartlett(n) blackman(n) boxcar(n) flattopwin(n, sym = c('symmetric', 'periodic')) gausswin(n, w = 2.5) hamming(n) hanning(n) triang(n) ```

Arguments

 `n` length of the filter; number of coefficients to generate. `w` the reciprocal of the standard deviation for `gausswin`. Use larger `a` for a narrower window. `sym` `'symmetric'` for a symmetric window, `'periodic'` for a periodic window.

Details

`triang`, unlike the bartlett window, does not go to zero at the edges of the window. For odd `n`, `triang(n)` is equal to `bartlett(n+2)` except for the zeros at the edges of the window.

A main use of `flattopwin` is for calibration, due to its negligible amplitude errors. This window has low pass-band ripple, but high bandwidth.

Value

Filter coefficients.

Author(s)

Original Octave versions by Paul Kienzle (`boxcar`, `gausswin`, `triang`) and Andreas Weingessel (`bartlett`, `blackman`, `hamming`, `hanning`). Conversion to R by Tom Short.

References

Oppenheim, A.V., and Schafer, R.W., Discrete-Time Signal Processing, Upper Saddle River, NJ: Prentice-Hall, 1999.

Gade, S., Herlufsen, H. (1987) “Use of weighting functions in DFT/FFT analysis (Part I)”, Bruel & Kjaer Technical Review No. 3.

Octave Forge https://octave.sourceforge.io/

`filter`, `fftfilt`, `filtfilt`, `fir1`

Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11``` ```n <- 51 op <- par(mfrow = c(3,3)) plot(bartlett(n), type = "l", ylim = c(0,1)) plot(blackman(n), type = "l", ylim = c(0,1)) plot(boxcar(n), type = "l", ylim = c(0,1)) plot(flattopwin(n), type = "l", ylim = c(0,1)) plot(gausswin(n, 5), type = "l", ylim = c(0,1)) plot(hanning(n), type = "l", ylim = c(0,1)) plot(hamming(n), type = "l", ylim = c(0,1)) plot(triang(n), type = "l", ylim = c(0,1)) par(op) ```

Example output

```Attaching package: 'signal'

The following objects are masked from 'package:stats':

filter, poly
```

signal documentation built on May 25, 2021, 9:06 a.m.