[R] Lyapunov - time series

[Gregorio Gutierrez]

Hi,
I wan’t to calculate the Lyapunov exponents of several time series (16 years 
of weekly observations each with a strong seasonal component).
I’ve got a reference that compares three methods: Feedforward Neural 
Networks, Thin-Plate Splines and Response Surface (Ellner & Turchin 1995, 
American Naturalist 145(3),343-375).
How can I estimate Lyapunov exponents (global and local) in R by any or all 
of this techniques?
Thanks for any advice,
Gregorio Fernandez