uses crt,graph;

{#### CONFIG ####}

const MAX = 10000;
N = 10;            {#### 0<N<50 ####}
lambda = 1;        {#### 0<lambda<50 ####}
beta =  5;       {#### beta>lambda ####}
DOT = 4;

var Data: array [1..MAX] of real;
Hist: array [1..N] of integer;


{#### FUNCTION ####}

function w(x:real):real;
begin

if (lambda <= x) and (x <= ((beta + lambda)/2)) then
w:= 4*(x-lambda)/sqr((beta - lambda));

if ((beta + lambda)/2 <= x) and (x <= beta) then
w:= 4*(beta - x)/sqr((beta - lambda));

end;



{#### PROCEDURE ####}

procedure DrawHist;
var i:integer;
	 step:real;
	 Max_Num:integer;
	 s:string;
	 k:real;
	 m1:real;
	 D:real;
	 hi:real;
	 wk:real;
begin
for i:=1 to N do Hist[i]:=0;{clearing array}

{#### CALCULATE HIST ####}

step:=lambda/N;
for i:=1 to MAX do inc(Hist[1+trunc((Data[i]-beta+lambda/2)/step)]);

{#### LOOK FOR Max_Num ####}

Max_Num:=0;
for i:=1 to N do if Max_Num<Hist[i] then Max_Num:=Hist[i];

{#### DRAWHIST ####}

m1:=0;D:=0;hi:=0;
for i:=0 to N-1 do begin
		  SetColor(14);
		  rectangle(
						round(i*GetMaxX/N),
						round(2*GetMaxY/3),
						round((i+1)*GetMaxX/N),
						round(2*GetMaxY/3*(1-Hist[i+1]/Max_Num)));
		  str(Hist[i+1],s);
		  SetColor(3);
		  SetTextStyle(DefaultFont, VertDir, 1);
		  OutTextXY(round(i*GetMaxX/N)+GetMaxX div N,
						round(2*GetMaxY/3)-40,s);
		  str((i+1)*step+beta-lambda/2:1:1,s);
		  SetColor(4);
		  OutTextXY(round(i*GetMaxX/N)+GetMaxX div N,
						round(2*GetMaxY/3)+10,s);
		  m1:=m1+((i+1)*step+beta-lambda/2)*Hist[i+1]/Max;
		  D:=D+sqr(((i+1)*step+beta-lambda/2))*Hist[i+1]/Max;
		  wk:=0.5*sqrt(2)*
				(sin(((i+1)*step+beta-lambda/2)*PI/2/lambda)*cos(PI*beta/2/lambda)
				-cos(((i+1)*step+beta-lambda/2)*PI/2/lambda)*sin(PI*beta/2/lambda)
				-sin((i*step+beta-lambda/2)*PI/2/lambda)*cos(PI*beta/2/lambda)
				+cos((i*step+beta-lambda/2)*PI/2/lambda)*sin(PI*beta/2/lambda));
		  hi:=hi+MAX*sqr(Hist[i+1]/MAX-wk)/wk;
		 end;
SetTextStyle(DefaultFont,HorizDir,1);
SetColor(9);
str(m1:0:DOT,s);
OutTextXY(100,2*GetMaxY div 3 +70,'m1(prakt)= '+s);
str(beta:0:DOT,s);
OutTextXY(100,2*GetMaxY div 3 +90,'m1(teor) = '+s);
D:=D-m1*m1;
str(D:0:DOT,s);
OutTextXY(250,2*GetMaxY div 3 +70,'D(prakt)= '+s);
D:=(PI*PI-32+8*PI)*lambda*lambda/4/PI/PI;
str(D:0:DOT,s);
OutTextXY(250,2*GetMaxY div 3 +90,'D(teor) = '+s);
str(hi:0:DOT,s);
OutTextXY(400,2*GetMaxY div 3 +80,'hi2 ='+s);
k:=-100000;
for i:=0 to GetMaxX do
			 if w(i*lambda/GetMaxX-lambda/2+beta)>k then k:=w(i*lambda/GetMaxX-lambda/2+beta);

SetTextStyle(DefaultFont, HorizDir, 1);
MoveTo(0,round(2*GetMaxY/3*(1-w(-lambda/2+beta)/k)));
SetColor(4);
for i:=0 to GetMaxX do begin
		LineTo(i,round(2*GetMaxY/3*(1-w(i*lambda/GetMaxX-lambda/2+beta)/k)));
	 end;
end;



{#### REV FUNCTION ####}

function F_Rev(x:real):real;
begin

if (lambda <= x) and (x <= ((beta + lambda)/2)) then
F_Rev:= 2*sqr((x-lambda))/sqr((beta - lambda));

if ((beta + lambda)/2 <= x) and (x <= beta) then
F_Rev:= 1 - 2*sqr((beta - x))/sqr((beta - lambda));
end;



{#### GENERATE AND FULL ARRAY #### }



procedure GenerateData;
var y:real;
	 i:integer;
begin
SetFillStyle(0,0);
OutTextXY(0,0,'Generating...');
 for i:=1 to MAX do begin
	y:=random;
	Data[i]:=F_Rev(y);
	end;
Bar(0,0,GetMaxX,GetMaxY);
end;


{#### FIND DRIVERS ####}


procedure OpenGraph;
 var Gd, Gm: Integer;
begin

 Gd := Detect;
 InitGraph(Gd, Gm, 'c:\tp\bgi');
end;



{#### OUT ####}
begin
ClrScr;
Randomize;
{GetParams;}
OpenGraph;
repeat
 GenerateData;
 DrawHist;
 delay(500);
until keypressed;
CloseGraph;
WriteLn('Good!');
end.