# devil's staircase
par k=1
x'=mod(x+w+k*sin(x),2*pi)
r'=r+w+k*sin(x)
w'=w
aux rho=r/400
@ xlo=0,ylo=-.1,xhi=6.3,total=400,trans=400,dt=1,meth=discrete
@ xp=w,yp=r,bound=100000
done