impz {signal}

Impulse-response characteristics

Description

Impulse-response characteristics of a discrete filter.

Usage

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

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

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

## S3 method for class 'impz'
plot(x, xlab = "Time, msec", ylab = "", type = "l",
    main = "Impulse response", ...)

## S3 method for class 'impz'
print(x, xlab = "Time, msec", ylab = "", type = "l",
    main = "Impulse response", ...)

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.

a

the autoregressive (recursive) coefficients of an ARMA filter.

n

number of points at which to evaluate the frequency response.

Fs

sampling frequency in Hz. If not specified, the frequencies are in per unit.

...

for methods of impz, arguments are passed to the default method. For plot.impz, additional arguments are passed through to plot.

x

object to be plotted.

xlab, ylab, main

axis labels anmd main title with sensible defaults.

type

as in plot, uses lines to connect the points

Details

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

Value

For impz, a list of class impz with items:

x

impulse response signal.

t

time.

Author(s)

Original Octave version by Kurt Hornik and John W. Eaton. Conversion to R by Tom Short.

References

https://en.wikipedia.org/wiki/Impulse_response

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

See Also

filter, freqz, zplane

Examples

bt <- butter(5, 0.3)
impz(bt)
impz(ellip(5, 0.5, 30, 0.3))