# impz: Impulse-response characteristics In signal: Signal Processing

## Description

Impulse-response characteristics of a discrete filter.

## Usage

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16``` ```## 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

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

## See Also

`filter`, `freqz`, `zplane`

## Examples

 ```1 2 3``` ```bt <- butter(5, 0.3) impz(bt) impz(ellip(5, 0.5, 30, 0.3)) ```

### 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.