Filter impulse response
[h,t]
= impz(hfilt)
[h,t]
= impz(hfilt,n)
[h,t]
= impz(hfilt,n,fs)
[h,t]
= impz(hfilt,[],fs)
impz(hfilt)
[h,t]
= impz(hs)
[h,t] =
impz(hs,Name,Value)
impz(hs)
impz
returns the impulse response based
on the current filter coefficients. This section describes common impz
operation
with discretetime filters, multirate filters, and filter System objects.
For more input options, refer to impz
in Signal Processing Toolbox™ documentation.
[
returns the impulse
response h
,t
]
= impz(hfilt
)h
and the corresponding time points w
at
which the impulse response of hfilt
is computed.
The impulse response is evaluated at 10 1second intervals—(0:9)'
.
[
returns
the impulse response evaluated at h
,t
]
= impz(hfilt
,n
)floor(n)
1second
intervals—(0:floor(n)1)'
.
[
returns
the impulse response evaluated at h
,t
]
= impz(hfilt
,n
,fs
)floor(n)
1/
fs
second
intervals—(0:floor(n)1)'/fs
.
[
returns
the impulse response evaluated at 10 h
,t
]
= impz(hfilt
,[],fs
)1/
fs
second
intervals—(0:9)'/fs
.
impz(
uses
FVTool to plot the impulse response of the filter. You can also provide
the optional input arguments hfilt
)n
and fs
with
this syntax.
[
returns the impulse response
for the filter System object™ h
,t
]
= impz(hs
)hs
. The impulse
response is evaluated at 10 1second intervals—(0:9)'
.
You can also provide the optional input arguments n
and fs
with
this syntax.
[
returns
an impulse response with additional options specified by one or more h
,t
] =
impz(hs
,Name,Value
)Name,Value
pair
arguments.
impz(hs)
uses FVTool to
plot the impulse response of the filter System object hs
.
Note
You can use 

Complex, 

Time vector of length 
Create a discretetime filter for a fourthorder, lowpass elliptic filter with a cutoff frequency of 0.4 times the Nyquist frequency. Use a secondorder sections structure to resist quantization errors. Plot the first 50 samples of the impulse response, along with the reference impulse response.
d = fdesign.lowpass(.4,.5,1,80); % Create a design object for the prototype filter.
Use ellip
to design a minimum
order discretetime filter in secondorder section form.
hd=design(d,'ellip');
Convert hd to fixedpoint, and plot the impulse response:
impz(hd); axis([1 75 0.2 0.35])