{ Pi_Jednoduse_Pro.pas               Copyright (c) Dalibor Martisek }
{ Program na vypocet cisla pi konvergenciou jednoducheho radu.      }
{                                                                   }
{ Datum:28.07.2006                             http://www.trsek.com }
 
unit Pi_Jednoduse_Unit;
 
interface
 
uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, Gauges;
 
type
  TForm1 = class(TForm)
    Label2: TLabel;
    Edit_Pi: TEdit;
    Button1: TButton;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
 
var
  Form1: TForm1;
  Stop : Boolean;
 
implementation
 
{$R *.DFM}
 
procedure TForm1.Button1Click(Sender: TObject);
var n,Cislo_Pi      :Extended;
    Znamenko,Citac  :Integer;
    PrevodRetezec   :String;
begin
  Cislo_Pi:=0;n:=0;Znamenko:=1;Citac:=0;Stop:=False;
  Repeat
    Cislo_Pi:=Cislo_Pi+Znamenko*1/(2*n+1);
    Znamenko:=-Znamenko;n:=n+1;
    inc(Citac);
    if Citac mod 100000 = 0 then
              begin
                //Edit_Pi.Text:=FloatToStr(4*Cislo_Pi);
                Str(4*Cislo_Pi:18:17,PrevodRetezec);
                Edit_Pi.Text:=PrevodRetezec;
                Application.ProcessMessages;
              end;
  Until Stop;
end;
 
procedure TForm1.Button2Click(Sender: TObject);
begin
 Stop:=True;
end;
 
end.