Example 1

uses MtxExpr, Math387, MtxVec, MtxVecTee, MtxVecEdit,
     LinearSystems, IirFilters, SignalUtils;

    procedure TForm1.Button1Click(Sender: TObject);
    var z,p,num,den, Response,b,c: Vector;
        Order: integer;
        k,Wc,d: TSample;
        A: Matrix;
    begin
        Order := 5; //design a fifth order filter.

        EllipticAnalog(Order,0.2,40,z,p,k);  //design analog protype
        //passband ripple 0.2dB, stopband attenuation 40dB
        Bilinear(z,p,k,2);  //Sampling frequency  = 2
        Wc := 0.6; //request a cutoff at 0.6 Hz
        LowpassToLowpassZ(z,p,k,WC,BilinearUnwarp(1));  //frequency transformation in z-domain
        ZeroPoleToTransferFun(num,den,z,p,k);

    //Alternative 1:
    //      EllipticAnalog(Order,0.2,40,z,p,k);  //design analog protype
    //      Bilinear(z,p,k,2);  //Sampling frequency  = 2
    //      ZeroPoleToTransferFun(num,den,z,p,k);
    //      Wc := 0.6; //request a cutoff at 0.6 Hz
    //      LowpassToLowpassZ(num,den,WC,BilinearUnwarp(1));  //frequency transformation in z-domain

    //Alternative 2:
    //      EllipticAnalog(Order,0.2,40,z,p,k);  //design analog protype
    //      Wc := BilinearPrewarp(0.6); //request a cutoff at 0.6 Hz
    //      LowpassToLowpass(z,p,k,WC);  //frequency transformation in s-domain
    //      Bilinear(z,p,k,2);  //Sampling frequency  = 2
    //      ZeroPoleToTransferFun(num,den,z,p,k);

    //Alternative 3:
    //      EllipticAnalog(Order,0.2,40,z,p,k);  //design analog protype
    //      ZeroPoleToStateSpace(A,B,C,D,z,p,k);
    //      Wc := BilinearPrewarp(0.6); //request a cutoff at 0.6 Hz
    //      LowpassToLowpass(A,B,C,D,WC); //frequency transformation in s-domain
    //      Bilinear(A,B,C,D,2);
    //      StateSpaceToZeroPole(z,p,k,A,B,C,D);
    //      ZeroPoleToTransferFun(num,den,z,p,k);

            FrequencyResponse(num,den,Response,64); //zero padding set to 64
            DrawIt(Response);
    end;

    #include "MtxVecCPP.h" //MtxVecCPP.cpp must be included in the project
    #include "MtxVecEdit.hpp"
    #include "MtxVecTee.hpp"
    #include "SignalUtils.hpp"
    #include "IirFilters.hpp"
    #include "LinearSystems.hpp"

    void __fastcall TForm1::BitBtn1Click(TObject *Sender)
    {

      Vector z, p, num, den, Response, b, c;
      int Order;
      double k,Wc,d;
      Matrix A;

      Order = 5; //design a fifth order filter.

    //	EllipticAnalog(Order,0.2,40,z,p,k);  //design analog protype
    //	//passband ripple 0.2dB, stopband attenuation 40dB
    //	Bilinear(z,p,k,2);  //Sampling frequency  = 2
    //	Wc = 0.6; //request a cutoff at 0.6 Hz
    //	LowpassToLowpassZ(z,p,k,Wc,BilinearUnwarp(1));  //frequency transformation in z-domain
    //	ZeroPoleToTransferFun(num,den,z,p,k);

    //Alternative 1:
    //	  EllipticAnalog(Order,0.2,40,z,p,k);  //design analog protype
    //    Bilinear(z,p,k,2);  //Sampling frequency  = 2
    //    ZeroPoleToTransferFun(num,den,z,p,k);
    //    Wc = 0.6; //request a cutoff at 0.6 Hz
    //	  LowpassToLowpassZ(num,den,Wc,BilinearUnwarp(1));  //frequency transformation in z-domain

    //Alternative 2:
    //	  EllipticAnalog(Order,0.2,40,z,p,k);  //design analog protype
    //    Wc = BilinearPrewarp(0.6); //request a cutoff at 0.6 Hz
    //    LowpassToLowpass(z,p,k,Wc);  //frequency transformation in s-domain
    //    Bilinear(z,p,k,2);  //Sampling frequency  = 2
    //    ZeroPoleToTransferFun(num,den,z,p,k);

    //Alternative 3:
        EllipticAnalog(Order,0.2,40,z,p,k);  //design analog protype
        ZeroPoleToStateSpace(A,b,c,d,z,p,k);
        Wc = BilinearPrewarp(0.6); //request a cutoff at 0.6 Hz
        LowpassToLowpass(A,b,c,d,Wc); //frequency transformation in s-domain
        Bilinear(A,b,c,d,2);
        StateSpaceToZeroPole(z,p,k,A,b,c,d);
        ZeroPoleToTransferFun(num,den,z,p,k);

        FrequencyResponse(num,den,Response,64); //zero padding set to 64
        DrawIt(Response);
    }

  using Dew.Math;
  using Dew.Math.Editors;
  using Dew.Math.Units;
  using Dew.Signal;
  using Dew.Signal.Units;
  using Dew.Math.Tee;
  using Dew.Signal.Tee;

  private void button1_Click(object sender, EventArgs e)
  {
      Vector z = new Vector(0);
      Vector p = new Vector(0);
      Vector num = new Vector(0);
      Vector den = new Vector(0);
      Vector Response = new Vector(0);
      Vector b = new Vector(0);
      Vector c = new Vector(0);
      double k,Wc,d;
      Matrix A = new Matrix(0,0);
      double FS = 2;

      int Order = 5; //design a fifth order filter.

      IIRFilters.EllipticAnalog(Order,0.2,40,z,p,out k);  //design analog protype
      //passband ripple 0.2dB, stopband attenuation 40dB
      LinearSystems.Bilinear(z,p,ref k,FS,true);  //Sampling frequency  = 2
      Wc = 0.6; //request a cutoff at 0.6 Hz
      LinearSystems.LowpassToLowpassZ(z,p,ref k,Wc, LinearSystems.BilinearUnwarp(1,FS));  //frequency transformation in z-domain
      LinearSystems.ZeroPoleToTransferFun(num,den,z,p,k);

      SignalUtils.FrequencyResponse(num, den, Response, 64, false, TSignalWindowType.wtRectangular, 0); //zero padding set to 64
      TeeChart.DrawIt(Response, "Design method 0", false);

//Alternative 1:
      IIRFilters.EllipticAnalog(Order,0.2,40,z,p,out k);  //design analog protype
      LinearSystems.Bilinear(z,p,ref k,FS,true);  //Sampling frequency  = 2
      LinearSystems.ZeroPoleToTransferFun(num,den,z,p,k);
      Wc = 0.6; //request a cutoff at 0.6 Hz
      LinearSystems.LowpassToLowpassZ(num,den,Wc,LinearSystems.BilinearUnwarp(1,FS));  //frequency transformation in z-domain

      SignalUtils.FrequencyResponse(num, den, Response, 64, false, TSignalWindowType.wtRectangular, 0); //zero padding set to 64
      TeeChart.DrawIt(Response, "Design method 1", false);

//Alternative 2:
      IIRFilters.EllipticAnalog(Order,0.2,40,z,p,out k);  //design analog protype
      Wc = LinearSystems.BilinearPrewarp(0.6,FS); //request a cutoff at 0.6 Hz
      LinearSystems.LowpassToLowpass(z,p,ref k,Wc);  //frequency transformation in s-domain
      LinearSystems.Bilinear(z,p,ref k, FS,true);  //Sampling frequency  = 2
      LinearSystems.ZeroPoleToTransferFun(num,den,z,p,k);

      SignalUtils.FrequencyResponse(num, den, Response, 64, false, TSignalWindowType.wtRectangular, 0); //zero padding set to 64
      TeeChart.DrawIt(Response, "Design method 2", false);

//Alternative 3:
      IIRFilters.EllipticAnalog(Order,0.2,40,z,p,out k);  //design analog protype
      LinearSystems.ZeroPoleToStateSpace(A,b,c,out d,z,p,k);
      Wc = LinearSystems.BilinearPrewarp(0.6,FS); //request a cutoff at 0.6 Hz
      LinearSystems.LowpassToLowpass(A,b,c,ref d,Wc); //frequency transformation in s-domain
      LinearSystems.Bilinear(A,b,c,ref d,2);
      LinearSystems.StateSpaceToZeroPole(z,p,out k,A,b,c,d);
      LinearSystems.ZeroPoleToTransferFun(num,den,z,p,k);

      SignalUtils.FrequencyResponse(num,den,Response,64,false,TSignalWindowType.wtRectangular,0); //zero padding set to 64
      TeeChart.DrawIt(Response,"Design method 3",false);
  }