Thanks for the reply jjac. Unfortunately i don't speak french :[
A better way of phrasing my question is. Can one transform the raw data into a phase space representation, and then fit the transformed data using equations describing phase space for the diffy q. This would be useful since...
1) For standard non-linear least squares, the standard approaches are to either
a) to use the jacobian to linearize, and proceed with linear regression, or to
b) linearize the raw data
2) When data needs to be "fit" to a complicated model (e.g. some non-linear differential equation) that...
Apologies for misleading title
1) Let's say I have some process e.g. an gravitational orbit or something that results in x = sin(w t) and y = cos (w t)
2) a. Clearly x and y are related, but using a simple correlation <x|y>/(<x^2><y^2>)**0.5 will result in 0. That is, x and y are not...
I saw some control diagrams for emotions on this website
http://www.emotionalcompetency.com/sadness.htm
and thought it would be cool to model it with a state space formalism. let's take x as a vector x = [anger, sadness, joy, etc...] where anger sadness and joy are quantities probabilities...