Matlab is available via CWRU site license from software.case.edu. If you have problems installing Matlab on a mac, consult the instructor. If you have problems installing Matlab under windows, consult Tim Anderson or ask PerceptIS. If you have problems installing Matlab under linux, let me know and I will try to find someone who can help you. Once you have Matlab installed, you can use a pair of excellent instructional tools developed by Polking and Arnold at Rice University. I use these tools and the author's guidebook, Ordinary Differential Equations using MATLAB (Prentice Hall) when teaching intro courses in ODEs. The authors also now have a textbook out, Differential Equations by Polking, Boggess and Arnold, as well as the guidebook. The program "dfield" lets you visualize the behavior of one-dimensional dynamical systems defined by ordinary differential equations. The program "pplane" lets you visualize two-dimensional autonomous (time-invariant) dynamical systems defined by a pair of ordinary differential equations. To use these programs, download them from one of the sites below (there is also a link to instructions) http://math.rice.edu/~polking/odesoft/ http://math.rice.edu/~dfield/ (download dfield7.m and pplane7.m) After starting Matlab, make sure you're in a directory containing (or with a link to) the file dfield7.m, and type >>dfield7 at the Matlab command prompt (don't type the ">>" part -- that's the prompt!) Once the equation window appears, you can customize the equation for the dynamical system of interest, save the equation for later use, visualize the direction field, etc. The dfield7 program starts with a "dfield7 Setup" window. Click "Proceed" to create a figure window showing the direction field. (To adjust the appearance of the direction field, click on View/Plot Browser. Then click on one of the tick marks to select the direction field object. You can adjust the line width (say from 0.5 to 2), for example, or click More Properties / Style-Appearance / Color to change the color.)