{*
采用RandG(0,1)来生成标准正态分布数据
1、一次生成10k个数据进行统计，速度相当快（Celeron 1.1G +256M ddr266）<1秒
2、绘出的曲线因为选择范围是8，故看起来并不是十分陡峭，可以将其改为16，那么就更加陡峭了
3、算法：映射到1..1000个数据点，大于等于+8的，正向封顶，设其为1000；小于等于 -8 的，负向封底，设其为1；如上面所说，为了使曲线看起来更加陡峭，可以在这里改为16封顶。其实，我最初是用+2-2来封及+4-4来封定封底的，效果已经不错了。
}
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, ExtCtrls, StdCtrls, Math;
type
TfrmMain = class(TForm)
imgAxis: TImage;
btnRandG: TButton;
GroupBox1: TGroupBox;
Splitter1: TSplitter;
grpControl: TGroupBox;
chkLogFrequency: TCheckBox;
chkDrawEdge: TCheckBox;
chkDrawLines: TCheckBox;
cboxCopyMode: TComboBox;
procedure FormShow(Sender: TObject);
procedure btnRandGClick(Sender: TObject);
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
totalCount :Integer;
sampleDatas :array[1..1000] of Integer;
procedure DrawAxis;
procedure GaussIt(const ASampleData:Extended);
procedure ReDraw;
procedure DrawEdge;//画边
procedure Log(const logName:string);
public
{ Public declarations }
end;
var
frmMain: TfrmMain;
implementation
{$R *.dfm}
procedure TfrmMain.DrawAxis;
begin
imgAxis.Canvas.Pen.Color :=clLime;
imgAxis.Canvas.Pen.Mode :=pmXor;
imgAxis.Canvas.MoveTo(imgAxis.Width div 2,imgAxis.Height);
imgAxis.Canvas.LineTo(imgAxis.Width div 2,0);
imgAxis.Canvas.MoveTo(0,imgAxis.Height -10);
imgAxis.Canvas.LineTo(imgAxis.Width,imgAxis.Height -10);
end;
procedure TfrmMain.ReDraw;
var
bmp :TBitmap;
i :Integer;
begin//根据数组里面的数和totalCount重新画图
bmp :=TBitmap.Create;
try
bmp.Width :=imgAxis.Width;
bmp.Height:=imgAxis.Height;
bmp.Canvas.Brush.Color :=clBlack;
bmp.Canvas.FillRect(bmp.Canvas.ClipRect);
bmp.Canvas.Pen.Color :=clRed;
bmp.Canvas.Pen.Width :=1;
//根据Image高度和1->1000发生的频数设置画线的高度
//应该计算出图像所能反映的最小分辨率，应能体现到频数有1的变化
for i:=1 to 1000 do
begin
sampleDatas[i] :=(sampleDatas[i]*(bmp.Height-10)) *250 div totalCount;//频数->频率->实际图像高度值
sampleDatas[i] :=bmp.Height-10 -sampleDatas[i];//高度转换为实际坐标
bmp.Canvas.MoveTo(i,bmp.Height-10);
if chkDrawLines.Checked then
bmp.Canvas.LineTo(i,sampleDatas[i]);
end;
//Log('height.txt');
if cboxCopyMode.Items[cboxCopyMode.ItemIndex]='cmBlackness' then
imgAxis.Canvas.CopyMode :=cmBlackness
else if cboxCopyMode.Items[cboxCopyMode.ItemIndex]='cmDstInvert' then
imgAxis.Canvas.CopyMode :=cmDstInvert
else if cboxCopyMode.Items[cboxCopyMode.ItemIndex]='cmMergeCopy' then
imgAxis.Canvas.CopyMode :=cmMergeCopy
else if cboxCopyMode.Items[cboxCopyMode.ItemIndex]='cmMergePaint' then
imgAxis.Canvas.CopyMode :=cmMergePaint
else if cboxCopyMode.Items[cboxCopyMode.ItemIndex]='cmNotSrcCopy' then
imgAxis.Canvas.CopyMode :=cmNotSrcCopy
else if cboxCopyMode.Items[cboxCopyMode.ItemIndex]='cmNotSrcErase' then
imgAxis.Canvas.CopyMode :=cmNotSrcErase
else if cboxCopyMode.Items[cboxCopyMode.ItemIndex]='cmPatCopy' then
imgAxis.Canvas.CopyMode :=cmPatCopy
else if cboxCopyMode.Items[cboxCopyMode.ItemIndex]='cmPatInvert' then
imgAxis.Canvas.CopyMode :=cmPatInvert
else if cboxCopyMode.Items[cboxCopyMode.ItemIndex]='cmPatPaint' then
imgAxis.Canvas.CopyMode :=cmPatPaint
else if cboxCopyMode.Items[cboxCopyMode.ItemIndex]='cmSrcAnd' then
imgAxis.Canvas.CopyMode :=cmSrcAnd
else if cboxCopyMode.Items[cboxCopyMode.ItemIndex]='cmSrcCopy' then
imgAxis.Canvas.CopyMode :=cmSrcCopy
else if cboxCopyMode.Items[cboxCopyMode.ItemIndex]='cmSrcErase' then
imgAxis.Canvas.CopyMode :=cmSrcErase
else if cboxCopyMode.Items[cboxCopyMode.ItemIndex]='cmSrcInvert' then
imgAxis.Canvas.CopyMode :=cmSrcInvert
else if cboxCopyMode.Items[cboxCopyMode.ItemIndex]='cmSrcPaint' then
imgAxis.Canvas.CopyMode :=cmSrcPaint
else if cboxCopyMode.Items[cboxCopyMode.ItemIndex]='cmWhiteness' then
imgAxis.Canvas.CopyMode :=cmWhiteness;
imgAxis.Canvas.CopyRect(imgAxis.Canvas.ClipRect,bmp.Canvas,bmp.Canvas.ClipRect);
//imgAxis.Canvas.Draw(0,0,bmp);//这个不能控制CopyMode
finally
bmp.Destroy;
end;
end;
procedure TfrmMain.GaussIt(const ASampleData:Extended);
var
x :Integer;
begin
Inc(totalCount);
//ShowMessage(FloatToStr(ASampleData));
//将这个随机数映射到1..1000，正数：500->1000，负数500->1
//ASampleData>=8 ---1000
// =0 ---500
// <=-8 ---1
x :=Round(ASampleData *1000);
//确定范围
if x>=4000 then x:=4000
else if x<=-4000 then x:=-4000;
x := (x +4001) shr 3;
Inc(sampleDatas[x]);//记录发生的频数，除以总次数就是频率了
//ShowMessage(IntToStr(x));
//ShowMessage(IntToStr(sampleDatas[x]));
end;
procedure TfrmMain.FormCreate(Sender: TObject);
begin
DoubleBuffered :=true;
DrawAxis;
end;
procedure TfrmMain.btnRandGClick(Sender: TObject);
var
i:Integer;
begin
totalCount :=0;
for i:=1 to 1000 do
sampleDatas[i]:=0;
for i:=1 to 100000 do//总计10000次
GaussIt(RandG(0,1));//标准正态分布
if chkLogFrequency.Checked then
Log('afterBtn.txt');
ReDraw;
if chkDrawEdge.Checked then
DrawEdge;
DrawAxis;
end;
procedure TfrmMain.FormShow(Sender: TObject);
begin
Left :=0;
btnRandG.Click;
end;
procedure TfrmMain.Log(const logName:string);
var
i:Integer;
log:TStringList;
str:string;
begin
log :=TStringList.Create;
try
for i:=1 to 1000 do
begin
str :=Format('%.4d : %d（频数）',[i,sampleDatas[i]]);
log.Add(str);
end;
str :=Format('总数：%d',[totalCount]);
log.Add(str);
totalCount :=0;
for i:=1 to 1000 do
inc(totalCount,sampleDatas[i]);
str :=Format('实际总数：%d',[totalCount]);
log.Add(str);
log.SaveToFile(logName);
finally
log.Destroy;
end;
end;
procedure TfrmMain.DrawEdge;//画边
var
i:Integer;
points :array[1..1000] of TPoint;
begin
for i:=1 to 1000 do
begin
points[i].x :=i;
points[i].y :=sampleDatas[i];
end;
imgAxis.Canvas.Polyline(points);
end;
end.
--------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------下面是Unit1.dfm
--------------------------------------------------------------------------------------------
object frmMain: TfrmMain
Left = 0
Top = 0
Width = 1012
Height = 455
Caption = 'frmMain'
Color = clBtnFace
Font.Charset = DEFAULT_CHARSET
Font.Color = clWindowText
Font.Height = -11
Font.Name = 'Tahoma'
Font.Style = []
OldCreateOrder = False
OnCreate = FormCreate
OnShow = FormShow
PixelsPerInch = 96
TextHeight = 13
object Splitter1: TSplitter
Left = 0
Top = 369
Width = 1004
Height = 4
Cursor = crVSplit
Align = alBottom
end
object GroupBox1: TGroupBox
Left = 0
Top = 0
Width = 1004
Height = 369
Align = alClient
Caption = 'GroupBox1'
TabOrder = 0
object imgAxis: TImage
Left = 2
Top = 15
Width = 1000
Height = 352
Align = alClient
Constraints.MaxWidth = 1000
Constraints.MinWidth = 1000
end
end
object grpControl: TGroupBox
Left = 0
Top = 373
Width = 1004
Height = 48
Align = alBottom
Caption = 'grpControl'
Constraints.MaxHeight = 48
Constraints.MinHeight = 24
TabOrder = 1
object btnRandG: TButton
Left = 16
Top = 16
Width = 75
Height = 25
Caption = 'btnRandG'
TabOrder = 0
OnClick = btnRandGClick
end
object chkLogFrequency: TCheckBox
Left = 128
Top = 16
Width = 97
Height = 17
Caption = 'chkLogFrequency'
TabOrder = 1
end
object chkDrawEdge: TCheckBox
Left = 240
Top = 16
Width = 97
Height = 17
Caption = 'chkDrawEdge'
Checked = True
Enabled = False
State = cbChecked
TabOrder = 2
end
object chkDrawLines: TCheckBox
Left = 344
Top = 16
Width = 97
Height = 17
Caption = 'chkDrawLines'
TabOrder = 3
end
object cboxCopyMode: TComboBox
Left = 464
Top = 16
Width = 145
Height = 21
ItemHeight = 13
ItemIndex = 0
TabOrder = 4
Text = 'cmBlackness'
Items.Strings = (
'cmBlackness'
'cmDstInvert'
'cmMergeCopy'
'cmMergePaint'
'cmNotSrcCopy'
'cmNotSrcErase'
'cmPatCopy'
'cmPatInvert'
'cmPatPaint'
'cmSrcAnd'
'cmSrcCopy'
'cmSrcErase'
'cmSrcInvert'
'cmSrcPaint'
'cmWhiteness')
end
end
end
