from pylab import *

x=0
y=10
theta=pi/100
xall=[x];
yall=[y];
ysum=0;

for t in range(100):
    ysum=ysum+y
    #theta=theta-pi/20*sign(y)
    #theta=theta-pi/200*y
    theta=theta-0.1*pi/20*y-0.2*ydif*pi/20
    #theta=theta-pi/200*y+0.02*ysum*pi/200
    x=x+2*cos(theta)
    ydif=2*sin(theta)
    y=y+ydif
    xall.append(x)
    yall.append(y)
    
plot(xall,yall)
xlabel('x')
ylabel('y')