Hi @Hardik
You can show your code and let's see what can be fixed. I suspect you used the 'zpk' command.
help zpk
ZPK Constructs zero-pole-gain model or converts to zero-pole-gain format.
Construction:
SYS = ZPK(Z,P,K) creates a continuous-time zero-pole-gain (ZPK) model
SYS with zeros Z, poles P, and gains K. SYS is an object of class @zpk.
SYS = ZPK(Z,P,K,Ts) creates a discrete-time ZPK model with sampling
time Ts (set Ts=-1 if the sample time is undetermined).
S = ZPK('s') specifies H(s) = s (Laplace variable).
Z = ZPK('z',TS) specifies H(z) = z with sample time TS.
You can then specify ZPK models directly as expressions in S or Z,
for example,
z = zpk('z',0.1); H = (z+.1)*(z+.2)/(z^2+.6*z+.09)
SYS = ZPK creates an empty zero-pole-gain model.
SYS = ZPK(D) specifies a static gain matrix D.
You can set additional model properties by using name/value pairs.
For example,
sys = zpk(1,2,3,'Variable','p','DisplayFormat','freq')
also sets the variable and display format. Type "properties(zpk)"
for a complete list of model properties, and type
help zpk.<PropertyName>
for help on a particular property. For example, "help zpk.IODelay"
provides information about the "IODelay" property.
Data format:
For SISO models, Z and P are the vectors of zeros and poles (set
Z=[] when there are no zeros) and K is the scalar gain.
For MIMO systems with NY outputs and NU inputs,
* Z and P are NY-by-NU cell arrays where Z{i,j} and P{i,j}
specify the zeros and poles of the transfer function from
input j to output i
* K is the 2D matrix of gains for each I/O channel.
For example,
H = zpk( {[];[2 3]} , {1;[0 -1]} , [-5;1] )
specifies the two-output, one-input ZPK model
[ -5 /(s-1) ]
[ (s-2)(s-3)/s(s+1) ]
Arrays of zero-pole-gain models:
You can create arrays of ZPK models by using ND cell arrays for Z,P
and a ND double array for K. For example, if Z,P,K are 3D arrays
of size [NY NU 5], then
SYS = ZPK(Z,P,K)
creates the 5-by-1 array of ZPK models
SYS(:,:,m) = ZPK(Z(:,:,m),P(:,:,m),K(:,:,m)), m=1:5.
Each of these models has NY outputs and NU inputs.
To pre-allocate an array of zero ZPK models with NY outputs and NU
inputs, use the syntax
SYS = ZPK(ZEROS([NY NU k1 k2...])) .
Conversion:
SYS = ZPK(SYS) converts any dynamic system SYS to the ZPK
representation. The resulting SYS is of class @zpk.
See also ZPK/EXP, ZPKDATA, ZPK, SS, FRD, DYNAMICSYSTEM.
Documentation for zpk
doc zpk
Other uses of zpk
control/zpk idParametric/zpk rffilter.rffilter/zpk
dsp.AllpassFilter/zpk mpc/zpk signal/zpk
DynamicSystem/zpk