>From: Herbert M Sauro <HSauro at fssc.demon.co.uk>
>Subject: Poincare sections
>Date: Thu, 10 Apr 1997 22:42:23 +0100
>>I'm not an expert nor a mathematician but could someone explain to me
>how one should go about (in practical terms) contructing a Poincare
>section for a system which does not have a natural periodicity (e.g an
>externally applied periodic forcing function)?
Just because it doesn't have a periodic forcing function *does not*
mean that it doesn't have a natural periodicity. A 2-d, linear ODE
with one eigenvalue on the imaginary axis and the other one being
zero has such a property.
>I have read that one has to put up a n-1 dimensional hyperplane across
>the flows and then identify the places on the plane where trajectories
>cross. How does one do this in a practical sense?
Yes, that's correct. I'll forward your question to my colleague in the
Math Dept. at NCSU who works on dynmaical systems. (We're working on
a model of the menstrual cycle.)
-Paul
