CS99 Fall 2002
Lab 1 (9/3)

0. Objectives:

      + Review administrative procedures
        - How lab is run
        - Sign up for NetPrint
        - Tour of course homepage
      + Introduction to Matlab
        - Command Window
        - MATLAB commands (addition)
        - Editing and running a script
        - Saving and printing a file
      + Homework hints
     
   What to hand in:      

      + e-mail to TA the file described in 3.0

1.   Administrative Procedures
       
1.1  Lab requirements

     + you must attend every lab (sign attendance sheet)
     + you *attempt* to complete the exercise and submit it
     + you must participate
     + you may work alone or in groups of any size
 
1.2  Net-Print

     Do you have an account? 
     If not, see http://www.cit.cornell.edu/net-print/

1.3  Course Homepage

     + Go to http://www.cs.cornell.edu/courses/cs99.

     + Navigating the site

2.0  Introduction to MATLAB 6.1

     + See http://www.mathworks.com for the MATLAB company's website.
     + Select Classfiles and Programs to run MATLAB.
     + Play time!

2.1  Commands in the Command Window         

     + You may enter commands here that the MATLAB "brain" will
       process.
     + You enter commands after the PROMPT, which looks like >>
     + If we say, enter $blah$, you type the letters b, l, a, and h
       with no spaces in between them after the prompt and then press
       the Enter key.
     + Use the arrow keys, Del, and Backspace to edit the command if
       you make a mistake.

2.2  General Help

     + For general help, enter $help$.
     + To find help on something called $blah$, you would enter
       $help blah$.

2.3  Demonstrating the Command Window            
     + enter $1+1$:

       Sample session:
       >> 1+1

       ans =

              2

     + MATLAB computes the expression 1+1 and reports the answer 2.
     + Yes, this really does resemble a calculator!

3.0  Demonstrating a Simple Script

     You will write your first program!  You can write commands
     in a separate file that MATLAB will understand and "compute".

     A Script File is a user-created file with a sequence of MATLAB
     commands in it.  The file must be saved with a '.m' extension to   
     its name.  A script file is executed by typing its name (without
     the '.m' extension) at the command prompt.

     MATLAB scripts are essentially programs because they contain a
     sequence of instructions that MATLAB executes.

     + From the menu, select File-->New-->M-file.
     + Inside the window, enter the following:

       % My first program!
        disp('Hello, world!')
        1+1

     + Select File-->Save As... .
     + In the window that pops up, choose the file name $hello.m$.
     + In the main window, make sure that current directory is the same
       directory as where you saved your program.       

     This process is known as SETTING YOUR PATH. A path is a
     location of a file or a directory/folder that contains files.
     You may type the directory/folder or select File-->Set Path.

     + After your path is set, enter $hello$ at the prompt in the
       command window.
     + MATLAB will generate output from your program if you made no
       mistake!

4.0  Some General Commands For the Command Window

       diary filename  saves the diary of a session
       clc             clears the command screen
       ^C              aborts any job inside MATLAB
       exit            exits MATLAB

5.0 Tutorials/Demos
                              
      More practice (just showing off some commands: don't worry about
      not knowing them!):

      >> theta=linspace(0, 2*pi, 100);
      >> x=cos(theta);
      >> y=sin(theta);
      >> plot(x,y);
      >> title('circle of unit radius');

      + To run a tutorial, enter $demo$ at prompt.