100*cos(13*atan2(x*sin(2*pi()*t)+y*cos(2*pi()*t), x*cos(2*pi()*t)-y*sin(2*pi()*t)))*heaviside(cos(13*atan2(x*sin(2*pi()*t)+y*cos(2*pi()*t), x*cos(2*pi()*t)-y*sin(2*pi()*t))))