t=linspace(0,2*pi,100);
l1 = [(cos(3*t)+sin(3*t))/3 ; cos(3*t)];
l2 = [(-cos(3*t)+sin(3*t))/3; sin(3*t)];

l = l1;
plot(l(1,:),l(2,:))
hold on
axis equal
l=l2;
plot(l(1,:),l(2,:))
l=(l1+l2)/2;
plot(l(1,:),l(2,:))
l=(l1+2*l2)/2;
plot(l(1,:),l(2,:))