matlab题:编写绘制n多边形的程序

functionploygon(n)
%Plotploygonwithnsides(n>2).

thita=linspace(0,2*pi,n+1);
holdon;
axisequal;
axisoff;
axis([-11-11]*1.2);
fori=1:length(thita)-1
thi1=thita(i);
thi2=thita(i+1);
x=[cos(thi1)cos(thi2)];
y=[sin(thi1)sin(thi2)];
plot(x,y,'k-');
end