Dear 293;         MATLAB this and that.        9/30/96

1) "Getting started with MATLAB" by Pratap is in the book store and has
   been since September 5  (53 copies left). If you are still insecurely 
   guessing  your way around with MATLAB I suggest you 
     a) buy or borrow this book,
     b) put aside 5 hours at the computer,
     c) slowly and relaxedly do the tutorials AND exercises.
        Reading the tutorials is not enough.  You don't know
        what kinds of mistakes you make, what kind of error
        messages you get, and how to correct, unless you
        actually do the exercises.

2) Please look at the course WWW page (address below) for MATLAB samples, etc.  

   a) There has been a sample there since 9/20 (on loops, overlay plots and 
   getting the last element of a column vector) that was intended to help 
   people with the Euler's method homework.  (I intended to send this out
   as email also but seem to have forgotten to do so.)

   b) pplane.m and psolve.m are there for help understanding systems of two
   first order ODEs.

3) Text semi-errors. People reported two problems with using the  MATLAB Euler's 
method example  on page 105 of the text.

  a) The top two lines belong in a separate file than the remaing 10.
     The name of this top file should be 'f.m'. Or, the top line of the 
     file can be changed and the name of the file similarly changed.

  b) The second 10 lines should be in a file. Unfortunately the file euler.m
     already exists on many computers and cannot be used.  You can't have
     two different functions with the same name.  So... if you want to copy
     the book example you need to change the top line to something different
     than  'euler' like say 'Euler', or 'Oiler', or 'eulor', or 'my_function',
     or 'whatever'.  The name of the file you put this in then needs to be
     Euler.m  (or whatever.m).

Unfortunately I was only told about these problems after the homework was turned in.
If you discover such things please let me know so I can pass on the information.