unit1.pas

来自「1、说明： 本书中所有的常用数值算法子过程按书中的章数分别放在以C开头」· PAS 代码 · 共 63 行

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls;
Function FUNC(X:real):real;
type
  TForm1 = class(TForm)
    Button1: TButton;
    Memo1: TMemo;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation
//PROGRAM D3R8
//Driver for routine QGAUS
uses
  unit2;
  {$R *.DFM}

Function FUNC(X:real):real;
begin
    FUNC:= X * Exp(-X);
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  F:TextFile;   I,NVAL:Integer;
  A,B,S,SS,X,X1,X2,DX,AAA:real;
const
  s1='%12.6f'; s3='%9.2f';
begin
  X1:=0;
  X2:=5;
  NVAL:= 10;
  DX:= (X2-X1)/NVAL;
  //输出计算结果到文件
  AssignFile(F, 'd:\delphi_shu\p3\d3r8.dat');
  Rewrite(F);
  Writeln(F, '     00 to     QGAUS     Expected');
  For I:= 1 To NVAL do
    begin
      X:=X1 + I * DX;
      QGAUS(X1,X,SS);
      AAA:=-(1+X)*Exp(-X)+(1+X1)*Exp(-X1);
      Writeln(F,Format(s3,[X]),Format(s1,[SS]),Format(s1,[AAA]));
    end;
  CloseFile(F);
  //屏幕显示计算结果
  memo1.Lines.LoadFromFile('d:\delphi_shu\p3\d3r8.dat');
end;

end.