Vector fields/direction fields/phase portraits

When you are working with systems of differential equations, it is often useful to look at either the vector field (direction field) of the system or the parametric plot of the solutions (or to just plot the individual solutions vs. time).  Let's take a look at how to do this with 2-dimensional systems (some of this is applicable to 3 dimensional systems as well).

(Sections with an * are optional.)

Vector fields
Parametric plot vs. time plots
Nonhomogeneous systems and higher dimensional systems*
Phase portraits of numeric approximations (think nonlinear systems)


Converted by Mathematica      July 20, 2003