Here are some hints on using Matlab:

1. Go to one of the computer sites and sign on a Macintosh. Click on the 'Sites' icon and drag an .sea file to the Mac Hard Disk (not the desktop) Then double click on the .sea file to unpack to a folder called Matlab.
2. Here is a link to a text file called dfield5.m which will solve differential equations of the first order. It was written by J. Polking of Rice, and is used by permission. To use it, use 'Save As' and save it as text in the Matlab folder. The double click on Matlab, and type dfield5. The rest is self-explanatory.
   Polking's web page has more information which you may be interested in.
3. R. Krasny of the math department has written a brief tutorial on Matlab, which is given as a pdf file here.
4. Here is a link to another program by Polking which does two first order differential equations. To solve F=ma, for example, set
   x'=y
   y'=F/m
5. phase4.m is a simple program which does 4 equations, that is, Newton's law in 2d. From this one you should be able to figure out any case you want. Use it with a function like keplerr.m

  6. Here is a program for the standard map: standard.m