I reccomend the book Dynamical Systems with Applications using Mathematica, by Stephen Lynch, which you can buy through Amazon or directly from Wolfram Research.
However, I can send you some Mathematica Notebooks (Version 8) that do what you want, but not at this moment, since I am kind of busy right now.
I can do that in a day or two if tou are interested.
________________________________________ De: J and B [email@example.com] Enviado el: jueves, 03 de febrero de 2011 03:32 a.m. Para: firstname.lastname@example.org Asunto: phase portraits
I am trying to find examples where Mathematica is used to study dynamic equations through the use of phase portraits, including their respective points: equilibrium, stability, attractors, bifurcations and so on.
Does any one have any work on this subject that he/she would mind sharing? I had many courses in this field in graduate school in the early 70's, and now I am trying to get a handle on them again. Back then I was using Fortran. Things have changed a lot.