Re: Phase portrait of one ode

[Juan Pablo Carbajal]

On Mon, Jun 17, 2013 at 11:20 AM, dedtadeas <address@hidden> wrote:
> Problem is that I am supposed to do phase portrait and plot it.
> 1. How to make and plot phase portrait of one dimensional function?
> 2. Deside which states of this system are stable.
>
> I would be really thankfull for any answer.

The phase portrait of a 1D system is just the line. However you can
study the dynamics by plotting xdot vs x. So if you have
xdot = f(x), then you plot f(x) vs. x and you can identify the zeros
and stability by eye. The best reference here is "Nonlinear Dynamics
and Chaos" by Steven H. Strogatz.

If your R is not a constant but a state variable you will need to
define its dynamics (I haven't read the article), in that case the
system will be 2D and of the form
Rdot = g(R,x)
xdot = f(R,x)