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.