gsignal: impz – R documentation

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impz

Impulse response of digital filter

Description

Compute the z-plane impulse response of an ARMA model or rational IIR filter. A plot of the impulse and step responses is generated.

Usage

impz(filt, ...)

## S3 method for class 'impz'
print(x, ...)

## S3 method for class 'Arma'
impz(filt, ...)

## S3 method for class 'Ma'
impz(filt, ...)

## S3 method for class 'Sos'
impz(filt, ...)

## S3 method for class 'Zpg'
impz(filt, ...)

## Default S3 method:
impz(filt, a = 1, n = NULL, fs = 1, ...)

Arguments

`filt`	for the default case, the moving-average coefficients of an ARMA model or filter. Generically, `filt` specifies an arbitrary model or filter operation.
`...`	for methods of `freqz`, arguments are passed to the default method. For `plot.impz`, additional arguments are passed through to plot.
`x`	object to be printed or plotted.
`a`	the autoregressive (recursive) coefficients of an ARMA filter.
`n`	number of points at which to evaluate the frequency response. If `n` is a vector with a length greater than 1, then evaluate the frequency response at these points. For fastest computation, `n` should factor into a small number of small primes. Default: 512.
`fs`	sampling frequency in Hz. If not specified (default = 2 * pi), the frequencies are in radians.

Value

For impz, a list of class "impz" with items:

x: impulse response signal.
t: time.

Note

When results of impz are printed, plot will be called to display a plot of the impulse response against frequency. As with lattice plots, automatic printing does not work inside loops and function calls, so explicit calls to print or plot are needed there.

Author(s)

Paul Kienzle, pkienzle@users.sf.net.
Conversion to R by Tom Short;
adapted by Geert van Boxtel, gjmvanboxtel@gmail.com

Examples

## elliptic low-pass filter
elp <- ellip(4, 0.5, 20, 0.4)
impz(elp)

xt <- impz(elp)

gsignal

Signal Processing

v0.3-1

GPL-3

Authors

Geert van Boxtel [aut, cre] (Maintainer), Tom Short [aut] (Author of 'signal' package), Paul Kienzle [aut] (Majority of the original sources), Ben Abbott [ctb], Juan Aguado [ctb], Muthiah Annamalai [ctb], Leonardo Araujo [ctb], William Asquith [ctb], David Bateman [ctb], David Billinghurst [ctb], Juan Pablo Carbajal [ctb], André Carezia [ctb], Vincent Cautaerts [ctb], Eric Chassande-Mottin [ctb], Luca Citi [ctb], Dave Cogdell [ctb], Carlo de Falco [ctb], Carne Draug [ctb], Pascal Dupuis [ctb], John W. Eaton [ctb], R.G.H Eschauzier [ctb], Andrew Fitting [ctb], Alan J. Greenberger [ctb], Mike Gross [ctb], Daniel Gunyan [ctb], Kai Habel [ctb], Kurt Hornik [ctb], Jake Janovetz [ctb], Alexander Klein [ctb], Peter V. Lanspeary [ctb], Bill Lash [ctb], Friedrich Leissh [ctb], Laurent S. Mazet [ctb], Mike Miller [ctb], Petr Mikulik [ctb], Paolo Neis [ctb], Georgios Ouzounis [ctb], Sylvain Pelissier [ctb], Francesco Potortì [ctb], Charles Praplan [ctb], Lukas F. Reichlin [ctb], Tony Richardson [ctb], Asbjorn Sabo [ctb], Thomas Sailer [ctb], Rolf Schirmacher [ctb], Rolf Schirmacher [ctb], Ivan Selesnick [ctb], Julius O. Smith III [ctb], Peter L. Soendergaard [ctb], Quentin Spencer [ctb], Doug Stewart [ctb], P. Sudeepam [ctb], Stefan van der Walt [ctb], Andreas Weber [ctb], P. Sudeepam [ctb], Andreas Weingessel [ctb]

Initial release

2021-05-02