function DrawRect(a,b,L,W,c)

 %Adda a Rectangle to the current window .Assumes hold is on.

 %The Rectangle has vertices (a,b),(a+L,b),(a,b+W),(a+L,b+W)

 %The c is color which is in the form of 'rgb vector' or one of the built-in

 %clolors such as 'r','g','y','b'

 x=[a,a+L,a+L,a];

 y=[b,b,b+W,b+W];

 fill(x,y,c);

 function DrawStar(x1,y1,dr,c)

 %the center of the five-stars is  at (x1,y1)

 %the radius of five-stars

 %the color of the five-star

 dtheta=*pi/;

 hold on

 axis equal off

 j=:;

 %外部五个点

 x=x1+dr*cos(j*dtheta+pi/);

 y=y1+dr*sin(j*dtheta+pi/);

 %内部五个点

 xl=x1+dr*cos(j*dtheta+*pi/)/;

 yl=y1+dr*sin(j*dtheta+*pi/)/;

 %Seperately take the ten points into vector

 X=[x(),xl(),x(),xl(),x(),xl(),x(),xl(),x(),xl()];

 Y=[y(),yl(),y(),yl(),y(),yl(),y(),yl(),y(),yl()];

 %then draw it.

 fill(X,Y,c);

 function DrawFlag(a,b,L1,W1,L2,r1,r2)

 %Adds a -star,-stripe Colonial flag to the current

 %Figure window.Assumes hold id on

 %The flag is L1-by-W1 with lower left corner at(a,b).

 %The length fo the blue area is L2.The ring of stars has radius r1 and its

 %center is the center of the blue area

 %the radius of the individual stars is r2

 clc

 close all

 figure

 hold on

 s=W1/;

 axis equal off

 for k=:

     %Draw the kth stripe

     bk=b+(k-)*s;

     if rem(k,)==&&k<=

         DrawRect(a,bk,L1,s,'r');

     elseif rem(k,)==&&k<=

         DrawRect(a,bk,L1,s,'w');

     elseif rem(k,)==&&k>=

         DrawRect(a+L2,bk,L1-L2,s,'r');

     else DrawRect(a+L2,bk,L1-L2,s,'w');

     end

 end

 DrawRect(a,b+*s,L2,*s,'b');

 %draw star

 theta=*pi/;

 xc=(a+L2)/;

 yc=9.5*s;

 for k=:

     xr=xc+r1*cos(k*theta+pi/);

     yr=yc+r1*sin(k*theta+pi/);

     DrawStar(xr,yr,r2,'w');

 end

 hold off