unit1.pas

delphi中实现数学曲线的方法

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  ExtCtrls, ComCtrls, Tabnotbk, StdCtrls, math, Buttons;

type
  TForm1 = class(TForm)
    TabbedNotebook1: TTabbedNotebook;
    BitBtn1: TBitBtn;
    BitBtn2: TBitBtn;
    BitBtn3: TBitBtn;
    BitBtn4: TBitBtn;
    BitBtn5: TBitBtn;
    Panel1: TPanel;
    Image1: TImage;
    Panel2: TPanel;
    Image2: TImage;
    Panel4: TPanel;
    Image4: TImage;
    Panel3: TPanel;
    Image3: TImage;
    procedure BitBtn2Click(Sender: TObject);
    procedure BitBtn3Click(Sender: TObject);
    procedure BitBtn1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure BitBtn4Click(Sender: TObject);
    procedure BitBtn5Click(Sender: TObject);

  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}


//绘制正弦曲线
procedure TForm1.BitBtn1Click(Sender: TObject);
var
  //存储曲线绘制的当前点
  x1:real;
  x2:real;
  y1:real;
  y2:real;
  n:real;
begin
  x1:=0;
  y1:=(form1.Image1.Left+form1.Image1.Width)/4+10;
  x2:=x1;
  y2:=y1;
  form1.Image1.Canvas.MoveTo(trunc(x2),trunc(y2));
  //定义曲线的起始点
  n:=0;
  while n<3.1415926*12 do //这里限定绘制的正弦曲线周期数
    begin
      x2:=x2+3.1415926/12;
      y2:=y1-40*sin(n);
      //绘制正弦曲线
      form1.image1.Canvas.LineTo(trunc(x2),trunc(y2));
      n:=n+3.1415926/180;
    end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  form1.image1.Canvas.pen.width:=2;
  form1.image2.Canvas.pen.width:=2;
  form1.image3.Canvas.pen.width:=2;
  form1.image4.Canvas.pen.width:=2;
  form1.image1.Transparent:=true;
  form1.image2.Transparent:=true;
  form1.image3.Transparent:=true;
  form1.image4.Transparent:=true;
end;

//绘制余弦曲线
procedure TForm1.BitBtn2Click(Sender: TObject);
var
  //存储曲线绘制的当前点
  x1:real;
  x2:real;
  y1:real;
  y2:real;
  n:real;
begin
  x1:=0;
  y1:=(form1.Image2.Left+form1.Image2.Width)/4+10;
  x2:=x1;
  y2:=y1;
  form1.Image2.Canvas.MoveTo(trunc(x2),trunc(y2));
  //定义曲线的起始点
  n:=0;
  while n<3.1415926*12 do //这里限定绘制的余弦曲线周期数
    begin
    x2:=x2+3.1415926/12;
    y2:=y1-40*cos(n);
    //绘制余弦曲线
    form1.image2.Canvas.LineTo(trunc(x2),trunc(y2));
    n:=n+3.1415926/180;
    end;
end;

//绘制正切曲线
procedure TForm1.BitBtn3Click(Sender: TObject);
var
  //存储曲线绘制的当前点
  x1:real;
  x2:real;
  y1:real;
  y2:real;
  n:real;
begin
  x1:=0;
  y1:=(form1.Image3.Left+form1.Image3.Width)/4;
  x2:=x1;
  y2:=y1;
  form1.Image3.Canvas.MoveTo(trunc(x2),trunc(y2));
  //定义曲线的起始点
  n:=0;
  while n<3.1415926*8 do //这里限定绘制的正切曲线周期数
    begin
      x2:=x2+3.1415926/3;
      if abs(cos(n))>0.0000001 then
      begin
        y2:=y1-60*sin(n)/cos(n);
        form1.image3.Canvas.LineTo(trunc(x2),trunc(y2));
        //绘制正切曲线
      end;
      n:=n+3.1415926/60;
    end;
end;

//绘制余切曲线
procedure TForm1.BitBtn4Click(Sender: TObject);
var
  //存储曲线绘制的当前点
  x1:real;
  x2:real;
  y1:real;
  y2:real;
  n:real;
begin
  x1:=0;
  y1:=(form1.Image4.Left+form1.Image4.Width)/4;
  x2:=x1-3;
  y2:=y1;
  form1.Image4.Canvas.MoveTo(trunc(x2),trunc(y2));
  //定义曲线的起始点
  n:=0;
  while n<3.1415926*8 do //这里限定绘制的余切曲线周期数
    begin
      x2:=x2+3.1415926/3;
      if abs(sin(n))>0.000001 then
      begin
        y2:=y1-60*cos(n)/sin(n);
        form1.image4.Canvas.LineTo(trunc(x2),trunc(y2));
        //绘制余切曲线
      end;
      n:=n+3.1415926/60;
    end;
end;

procedure TForm1.BitBtn5Click(Sender: TObject);
begin
  close;
end;

end.