uses MtxExpr, Math387, MtxVec, SignalUtils, MtxVecTee, MtxVecEdit, IIRFilters;

  procedure TForm42.Button1Click(Sender: TObject);
  var b,c,Response,Response1,num,den: Vector;
      State: TIirState;
      n,i: integer;
  begin
      Tone(b,300,6/300,0,1);

  //   Alternative: try gaussian noise
  //    b := RandGauss(300);

      c.Size(b);
      ChebyshevIFilter(6,0.2,[0.6],ftLowpass,false,num,den);
      FillChar(State,SizeOf(State),0);
      IirInit(num,den,State);
      try
  //Alternative 1, IIR streaming
          n := 10;
          for i := 0 to (b.Length div n) - 1 do
          begin
               b.SetSubRange(i*n,n);
               c.SetSubRange(i*n,n);
               IirFilter(b,c,State);
          end;

  //Alternative 2 single block filter (does not require TIirState)
  //                c.Copy(b);
  //                IirFilter(c,num,den,True);

  //Alternative 3 single block
  //                c.Copy(b);
  //                IirFilter(c,State);

          c.SetFullRange;
          b.SetFullRange;
          DrawIt([b,c],['Original signal','Filtered signal']);
          FrequencyResponse(b,nil,Response,8,True,wtHanning);
          FrequencyResponse(c,nil,Response1,8,True,wtHanning);
          DrawIt([Response,Response1],['Orig. signal','Filtered']);
      finally
          IirFree(State);
      end;
  end;

  #include "MtxExpr.hpp"
  #include "MtxVecEdit.hpp"
  #include "MtxVecTee.hpp"
  #include "SignalUtils.hpp"
  #include "IIRFilters.hpp"
  #include <string.h>

  void __fastcall TForm1::BitBtn1Click(TObject *Sender)
  {
      sVector b,c, Response1, Response, num, den;
      TIirState State;
      TToneState ToneState;
      int i,n;

      b.Size(300);
      ToneInit(6.0/300,0.0,1.0,ToneState,false);
      Tone(b,ToneState);

    //   Alternative: try gaussian noise
    //   b.RandGauss();

      c.Size(b);
      ChebyshevIFilter(6,0.2,OPENARRAY(double,(0.6)),ftLowpass,false,num,den);
      memset(&State,0,sizeof(State));
      IirInit(num,den,State);
      try
      {
    //Alternative 1, IIR streaming
        n = 10;
        for (i = 0; i < (b.Length/n); i++)
        {
           IirFilter(b(i*n,i*n+n-1),c(i*n,i*n+n-1),State);
        }

    //Alternative 2 single block filter (does not require TIirState)
    //                c.Copy(b);
    //                IirFilter(c,num,den,true);

    //Alternative 3 single block
    //                c.Copy(b);
    //                IirFilter(c,State);

        DrawIt(OPENARRAY(TVec*,(b,c)),OPENARRAY(AnsiString,("Original signal","Filtered Signal")));
        FrequencyResponse(b,NULL,Response,8,True,wtHanning);
        FrequencyResponse(c,NULL,Response1,8,True,wtHanning);
        DrawIt(OPENARRAY(TVec*,(Response,Response1)),OPENARRAY(AnsiString,("Spectrum: original signal","Spectrum: filtered signal")));
      }
      __finally
      {
        IirFree(State);
      }
  }