[sdiy] semi OT: nonlinear idiot needs help

[Czech Martin]

I think by now I have a good position in understanding linear
time invariant systems. I mean convolution, transforms,
transfer function etc. (thanx Magnus, Don, Juergen and all
the others who teached me).
This linear stuff seems pretty much complete and all worked out.

But: we all know (not only guitar players) that the
real fun starts with nonlinearity at least.

I only know little about nonlinear or time varying systems.
I knew basic control theory about that, and some chaos
stuff like Lorentz attractors and and Runge-Kutta
integration of first order non linear differential
equations and stuff like that.

Is there anything like a complete theory of said systems?
I guess it's far away from completeness and still growing.
Any hints?

Thanx.

m.c.