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 D2R5
//Driver for routine LOCATE
uses
  unit2;
  {$R *.DFM}
procedure TForm1.Button1Click(Sender: TObject);
var
  XX:array[0..100] of real;
  X:real;
  F:TextFile;  I,J:Integer;
const
  N=100; s1='%14.6f'; s3='#0';
begin
  //Create array to be searched
  For I:=1 to N do
    XX[I]:= EXP(I/20)-74;
  //輸出計算結果到文件
  AssignFile(F, 'd:\delphi_shu\p2\d2r5.dat');
  Rewrite(F);
  Writeln(F, 'Result of:    j=0 indicates x too small');
  Writeln(F, '              j=100 indicates x too large');
  Writeln(F, '       locate       j           xx(j)         xx(j+1)');
  //For test
  For I:= 1 To 19 do
  begin
      X:=-100 + 200 * I / 20;
      LOCATE(XX, N, X, J);
      If J = 0 Then
        Writeln(F,Format(s1,[X]),'      ',FormatFloat(s3,J),'         ',
          'lower lim',Format(s1,[XX[J+1]]))
      Else If J = N Then
        Writeln(F,Format(s1,[X]),'    ',FormatFloat(s3,J),'    ',
          Format(s1,[XX[J]]),'     upper lim ')
      Else if (J<>0) and (J<>N) Then
        Writeln(F,Format(s1,[X]),'     ',FormatFloat(s3,J),'    ',
          Format(s1,[XX[J]]),Format(s1,[XX[J+1]]));
  end;
  CloseFile(F);
  //屏幕顯示計算結果
  memo1.ScrollBars:=ssVertical;
  memo1.Lines.LoadFromFile('d:\delphi_shu\p2\d2r5.dat');
end;
end.