Z-plane zero-pole plot for discrete-time filter System object
[zLoc,pLoc,tLoc] = zplane(filt)
the zeros and poles of the filter System
with the unit circle for reference in the filter visualization tool
(fvtool). Each zero is represented with a
each pole with a
'x' on the plot. Multiple zeros
and poles are indicated by the multiplicity number shown to the upper
right of the zero or pole.
When you call the
step method on the filter System
a fixed-point input, the filter becomes a quantized fixed-point filter,
filtQuant is a quantized filter,
the poles and zeros of the quantized and unquantized filters. The
+ represent the zeros
and poles of the quantized filter
plot includes the unit circle for reference.
[ returns the vector
of locations for zeros, poles, and text objects.
the vector of locations of zeros,
pLoc is the vector
of locations of poles, and
tLoc is the vector of
locations of the axes/unit circle line and text objects which are
present when there are multiple zeros or poles. In case there are
no zeros or poles,
set to the empty matrix
A filter System object.
The following Filter System objects are supported by this analysis function:
comma-separated pairs of
the argument name and
Value is the corresponding value.
Name must appear inside quotes. You can specify several name and value
pair arguments in any order as
'Arithmetic'— Value types:
When you specify
the function performs double- or single-precision analysis. When you
'fixed' , the arithmetic changes depending
on the setting of the
and whether the System
object is locked or unlocked.
When you do not specify the arithmetic for non-CIC structures, the function uses double-precision arithmetic if the filter System object is in an unlocked state. If the System object is locked, the function performs analysis based on the locked input data type. CIC structures only support fixed-point arithmetic.
Vector of locations of zeros.
Vector of locations of poles.
Vector of locations of axes/unit circle line and text objects.
Create a Fourth-order IIR digital filter with a cutoff frequency of 0.6. Plot the poles and zeros of this filter.
[b,a] = ellip(4,.5,20,.6); zplane(b,a);
Quantize the filter by passing a fixed-point input through the filter algorithm. Plot the quantized and unquantized poles and zeros associated with this filter.
iirFilt = dsp.IIRFilter('Numerator',b,'Denominator',a); in = fi(randn(15,6),1,15,3); out = iirFilt(in); zplane(iirFilt)