unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    Memo1: TMemo;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation
//PROGRAM D4R21
//Driver for routine BESSI0
uses
  unit2;
{$R *.DFM}
procedure TForm1.Button1Click(Sender: TObject);
var
  ACTUAL:array[1..5] of real;X:array[1..5] of real;
  F:TextFile;  j:Integer; 
const
  s1='%8.2f';s2='0.000000e+0';
begin
  ACTUAL[1]:=1.010025;       ACTUAL[2]:=1.266066;
  ACTUAL[3]:=1.393726;       ACTUAL[4]:=2.279585;
  ACTUAL[5]:=27.23987;
  X[1]:=0.2;     X[2]:=1;
  X[3]:=1.2;     X[4]:=2;
  X[5]:=5;
  //輸出計算結(jié)果到文件
  AssignFile(F, 'd:\delphi_shu\p4\d4r21.dat');
  Rewrite(F);
  Writeln(F, '     X         Actual       BESSI0(X)');
  For j:= 1 To 5 do
  begin
    Writeln(F,Format(s1,[X[j]]),'    ',FormatFloat(s2,Actual[j]),
        '    ',FormatFloat(s2,BESSI0(X[J])));
  end;
  CloseFile(F);
  //屏幕顯示計算結(jié)果
  memo1.Lines.LoadFromFile('d:\delphi_shu\p4\d4r21.dat');
end;

end.