To obtain many closed curves,
curvatureParam = integer.
In formula below:
scale = curvatureParam/120
The curvature function of this curve is
kappa(s) = scale*(2 + cos(s))
The ODE for the velocity v(s) is
v'(s) = kappa(s)*rot(90)*v(s)
The curve c(s) is determined by c'(s)=v(s)
Since the curves are very different in size, they are
rescaled at some parameter steps.