unit Unit1;

 interface

 uses

   Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

   Dialogs, StdCtrls, ExtCtrls;

 type

   TForm1 = class(TForm)

     Image1: TImage;

     Button1: TButton;

     Label1: TLabel;

     Label2: TLabel;

     Label3: TLabel;

     Label4: TLabel;

     Label5: TLabel;

     Label6: TLabel;

     procedure Button1Click(Sender: TObject);

   private

     { Private declarations }

   public

     { Public declarations }

   end;

 var

   Form1: TForm1;

 implementation

 {$R *.dfm}

 procedure TForm1.Button1Click(Sender: TObject);

 var

   x,l:Integer;

   y,a:double;

 begin

   Image1.Picture.Bitmap:=TBitMap.Create;

   Image1.Picture.Bitmap.Width:=Image1.Width;

   Image1.Picture.Bitmap.Height:=Image1.Height;

   l:=Image1.Picture.Bitmap.Width;
     {下面的语句用于绘制直角坐标系}

   Image1.Canvas.MoveTo(,(Image1.Height div ));

   Image1.Canvas.Pen.Color:=clBlue;

   Image1.Canvas.LineTo(Image1.Width,(Image1.Height div ));{绘制函数图像X轴}

   Image1.Canvas.MoveTo((Image1.Width div ),Image1.Height);

   Image1.Canvas.LineTo((Image1.Width div ),);{绘制函数图像Y轴}

   for x:= to l do

     begin

       a:=(x/l)**Pi;{角度化弧度}

       y:=sin(*a);{为了加强美观效果，这里讲振幅设为2}

       y:=y*(Image1.Picture.Bitmap.Height/);

       y:=y+(Image1.Picture.Bitmap.Height/);

       Image1.Picture.Bitmap.Canvas.Brush.Style:=bsSolid;

       Image1.Picture.Bitmap.Canvas.Pixels[Trunc(x),Trunc(y)]:=clRed;{当然也可以用LineTo过程来实现，但是要注意设置Pen.Width到合适的值}

     end;

   label1.Visible:=true;

   Label2.Visible:=true;

   label3.Visible:=true;

   Label4.Visible:=true;

   label5.Visible:=true;

   Label6.Visible:=true;

 end;

 end.