Example 1

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

    procedure TForm1.Button1Click(Sender: TObject);
    var z,p, num,den, FreqFr,Response: Vector;
        Order: integer;
        k,Wc,BW: TSample;
    begin
        Order := 5; //design a fifth order filter.
        EllipticAnalog(Order,0.2,40,z,p,k);  //design analog protype
        Wc := Sqrt(0.2*0.6);
        BW := 0.6-0.2;
        LowpassToBandstop(z,p,k,WC,BW);  //frequency transformation in s-domain
        ZeroPoleToTransferFun(num,den,z,p,k);
        //Define the frequency grid (logarithmic)
        FreqFr.Length := 1000;
        LogRamp(FreqFr,-1,1); //between 0.1 (=10^(-1)) and 10 (=10^1) rad/sec
        FrequencyResponseS(num,den,FreqFr,Response); //Laplace
        DrawIt(Response); //Y axis linear, X axis logarithmic
    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, FreqFr,Response;
      int Order;
      double k,Wc,BW;

      Order = 5; //design a fifth order filter.
      EllipticAnalog(Order,0.2,40,z,p,k);  //design analog protype
      Wc = Sqrt(0.2*0.6);
      BW = 0.6-0.2;
      LowpassToBandstop(z,p,k,Wc,BW);  //frequency transformation in s-domain
      ZeroPoleToTransferFun(num,den,z,p,k);
      //Define the frequency grid (logarithmic)
      FreqFr->Length = 1000;
      LogRamp(FreqFr,-1,1); //between 0.1 (=10^(-1)) and 10 (=10^1) rad/sec
      FrequencyResponseS(num,den,FreqFr,Response); //Laplace
      DrawIt(Response); //Y axis linear, X axis logarithmic
    }

  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 FreqFr = new Vector(0);
         double k,Wc,BW;
         double FS = 2;
         int Order = 5; //design a fifth order filter.

         IIRFilters.EllipticAnalog(Order,0.2,40,z,p,out k);  //design analog protype
         Wc = Math.Sqrt(0.2*0.6);
         BW = 0.6 - 0.2;
         LinearSystems.LowpassToBandstop(z,p,ref k,Wc,BW);  //frequency transformation in s-domain
         LinearSystems.ZeroPoleToTransferFun(num,den,z,p,k);
      //Define the frequency grid (logarithmic)
         FreqFr.Length = 1000;
         SignalUtils.LogRamp(FreqFr,-1,1); //between 0.1 (=10^(-1)) and 10 (=10^1) rad/sec
         SignalUtils.FrequencyResponseS(num,den,FreqFr,Response,0); //Laplace
         TeeChart.DrawIt(Response,"Frequency response",false); //Y axis linear, X axis logarithmic
    }

          s(Wu - Wl)
  s --> -------------
         s^2 + Wu*Wl

  Wl - lower cutoff frequency
  Wu - upper cutoff frequency