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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