procedure TForml.Button2Click(Sender: TObject);
var
pol: array[1..3] of TPoint;
begin
pol[l].x := 10;
polfl].y := 50;
pol[2].x := 40;
pol[2].y := 10;
pol[3].x := 70;
pol[3].y := 50;
Forml .Canvas.Polygon(pol);
end;
Sektor
Ellips yoki aylana sektori pie usuli bilan chizilib, chaqirish
instruksiyasi quyidagi umumiy ko‘rinishga ega:
Nuqta
Canvas obyektining pixels xossasi tipidagi ikki olchovli massiv
bo‘lib. har bir soha nuqtasining rangi haqidagi ma’lumotni o‘z ichiga
oladi. Pixels xossasidan foydalanib ixtiyoriy nuqta rangini o‘zgartirish.
ya’ni nuqta chizish mumkin. Misol uchun:
126
y = 2- Sinx • e|- funksiyasi grafigini chiqaradi.
TForml = class(TForm)
Buttonl: TButton;
procedure ButtonlClick(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
Var
Forml: TForml;
implementation
{$R *.dfm}
Function f(x:real):real;
Begin
f:=2*Sin(x)*exp(x/5) ;
end;
Procedure GrOfFunc;
Var
xl,x2:real;
yl,y2:real;
x:real;
y:real;
dx:real;
l,b:Integer;
w,h:Integer;
mx,my:real;
xO,yO:Integer;
Begin
1:=10;
b:=Forml.ClientHeight-20;
127
h:=Form1. ClientHeight-40;
w:=Forml.Width-40;
xl:=0;
x2:=25;
dx:=0.01;
yl:=f(xl);
y2:=f(xl);
x:=xl;
Repeat
y := f (x);
if y < yl then yl:=y;
if y > y2 then y2:=y;
x:=x+dx; until (x >= x2);
my:=h/abs(y2-yl);
mx:=w/abs(x2-xl);
x0:=l;
yO:=b-Abs(Round(yl*my));
with forml.Canvas do
Begin
/ / °si
MoveTo(l,b);LineTo(l,b-h);
MoveTo(x0,y0);LineTo(x0+w,y0);
TextOut(l+5,b-h,FloatToStrF(y2,ffGeneral,6,3));
TextOut(l+5,b,FloatToStrF(yl,ffGeneral,6,3));
x:=xl; repeat
y:=f(x);
Pixels[xO+Round(x*mx),y0 - Round(y*my)]:=clRed;
x:=x+dx;
Until (x >= x2);
end;
end;
procedure TForml.ButtonlClick(Sender: TObject);
begin
Buttonl.Visible:=false;
GrOfFunc;
end;
end.
Asosiy vazifani GrOfFunc protsedurasi bajaradi. Awal [xl,x2]
oraliqda funksiyaning maksimal (y2) va minimal (yl) qiymatlari
hisoblanadi. So‘ngra koordinatalar y ki bo‘yicha masshtab hisoblanadi.
Shundan so‘ng protsedura grafikni quradi.
128
jiDI il
GrOfFunc protsedurasi tomonidan qurilgan grafik.
Keltirilgan dastur universal xarakterga ega. 0 ‘zga funksiya grafigini
chizish uchun f (x) tanasini o‘zgartirish yetarli.
Dastur to‘g‘ri ishlaydi, agar funksiya ham musbat, ham manfiy
qiymatlami qabul qilsa.
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