implementation
//PROGRAM D4R27
//Driver for routine BESSJAN
uses
  unit2;
{$R *.DFM}
procedure TForm1.Button1Click(Sender: TObject);
var
  ACTUAL:array[0..4] of real; FF:array[0..4] of real;
  F:TextFile;  j:Integer;
  A,X:real;IH:integer;
const
  s1='%6.2f';s2='.000000e+00';S3='###0';
begin
  ACTUAL[0]:=0.540974;        ACTUAL[1]:=0.0917017;
  ACTUAL[2]:=0.00923641;      ACTUAL[3]:=0.000662379;
  ACTUAL[4]:=0.0000368921;
  A:=0.5;
  IH:=1;
  X:=0.5;
  //輸出計算結果到文件
  AssignFile(F, 'd:\delphi_shu\p4\d4r27.dat');
  Rewrite(F);
  Writeln(F, 'N    A    IH   X       Actual         BESSJAN');
  BESJAN(X,A,4,IH,FF);
  For j:= 0 To 4 do
  begin
      Writeln(F,FormatFloat(s3,j),Format(s1,[A]),'   ',
          FormatFloat(s3,IH),Format(s1,[X]),'    ',
          FormatFloat(s2,Actual[j]),'    ',FormatFloat(s2,FF[J]));
  end;
  CloseFile(F);
  //屏幕顯示計算結果
  memo1.Lines.LoadFromFile('d:\delphi_shu\p4\d4r27.dat');
end;