.Modelica_LinearSystems2.WorkInProgress.DiscreteZerosAndPoles.'constructor'.fromZerosAndPoles

Information

This function constructs a transfer function from denominator and numerator zeros, as well as a gain. Example:

                          (s+1)
  zp = 4* -------------------------------------
           (s - 1)*(s - (2+j*3))*(s - (2-j*3))

with j=sqrt(-1), is defined as

   import Complex;
   import Modelica_LinearSystems2.ZerosAndPoles;

   zp = ZerosAndPoles(z = {Complex(-1,0)},
                      p = {Complex(1,0),
                           Complex(2,3),
                           Complex(2,-3)},
                           k=4);

Since only transfer functions with real coefficients are supported, complex roots must be defined as conjugate complex pairs. It is required that complex conjugate pairs must directly follow each other as above. An error occurs if this is not the case.

Interface

encapsulated function fromZerosAndPoles
  import Modelica;
  import Modelica_LinearSystems2;
  import Modelica_LinearSystems2.WorkInProgress.DiscreteZerosAndPoles;
  import Modelica_LinearSystems2.Internal;
  import Complex;
  import Modelica.Utilities.Streams.print;
  input Complex z[:] = fill(Complex(0), 0) "Zeros (Complex vector of numerator zeros)";
  input Complex p[:] = fill(Complex(0), 0) "Poles (Complex vector of denominator zeros)";
  input Real k = 1.0 "Constant multiplied with transfer function";
  input Modelica.Units.SI.Time Ts = 1 "Sample time";
  input Modelica_LinearSystems2.Utilities.Types.Method method = Modelica_LinearSystems2.Utilities.Types.Method.Trapezoidal "Discretization method";
  input String uName = "" "input name";
  input String yName = "" "output name";
  output DiscreteZerosAndPoles dzp(redeclare Real n1[Internal.numberOfRealZeros(z)], redeclare Real n2[integer((size(z, 1) - Internal.numberOfRealZeros(z))/2), 2], redeclare Real d1[Internal.numberOfRealZeros(p)], redeclare Real d2[integer((size(p, 1) - Internal.numberOfRealZeros(p))/2), 2]) "ZerosAndPoles transfer functions of the zeros, poles and k";
end fromZerosAndPoles;