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PHYS210: MATLAB LAB 2
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o Login and open a terminal window and have a browser pointed to 
  these notes as usual 

o In the previous lab we learned how to use Matlab to perform simple
  calculations interactively, i.e. by explicitly typing expressions 
  and commands in the command window

o Paralleling what we did in Maple, we now want to learn how to 
  prepare Matlab commands in a text file --- a.k.a. a Matlab
  source file --- that can then be "read into" a Matlab session

o Typing the commands into a source file has the same benefits in 
  Matlab as it does in Maple, and, again, is particularly crucial when 
  we are writing programs in the language

o As we will see in more detail, a fundamental unit of Matlab
  programming is the 'function', which is completely analogous to
  the 'procedure' in Maple.  Each function has a name---chosen 
  by the programmer---such as  ...

     myfcn
     minmax
  
  ... etc.

o In addition to functions, the other key unit of Matlab programming
  is known as a 'script' and is simply a sequence of an arbitrary 
  number of Matlab commands and statements, which will often include 
  calls to functions that the user/programmer has defined

o For example, all of the commands that you typed at the Matlab 
  prompt in the last lab, if they were entered in a text file, 
  would constitute a script

o Given this brief description of the two main units of Matlab programs,
  there are two basic rules that govern how we must prepare and 
  process Matlab source files:

  1) All Matlab source files (which are text files) must have 
     names that include an extension .m

     For example ---

        foo.m
        myfunction.m
        myscript.m

     ... are valid filenames in this context, while  ...

        foo
        myfunction.x
        myscript.somethingelse
     
     ... are not

   2) There is no analog of the Maple 'read' command in Matlab.
      Rather, in order to make Matlab process ("read") a source file,
      we simply type the filename WITHOUT THE .m EXTENSION at the 
      prompt.

      For the time being, in order for this to work we need to 
      ensure that the source file RESIDES IN THE DIRECTORY FROM 
      WHICH MATLAB WAS STARTED/LAUNCHED

o Let's see how this works ...

o First, in a terminal window, change to the 'matlab' directory 
  that we created in the last lab

% cd ~/matlab
% pwd
/home/phys210d/matlab

  If you haven't yet made the directory, then do so now, via ...

% cd
% mkdir matlab
 
  ... then execute ...

% cd ~/matlab
% pwd
/home/phys210d/matlab

o Now, we will copy a (very) basic script file, myscript.m, from 
 ~phys210/matlab

% cp ~phys210/matlab/myscript.m .

o Examine the contents of the file

% cat myscript.m

   % This is a simple Matlab script
   a = 1
   b = [1 2 3 4]
   c = [1:3:22]
   d = linspace(0, 1, 6)
   e = [10; 20; 30]

o Now, start Matlab FROM THE COMMAND LINE IN THE SAME TERMINAL WINDOW 
  SO THAT THE APPLICATION STARTS IN THE DIRECTORY ~/matlab

% matlab &

o In the Matlab command window, enter the following ...

>> myscript
   
  ... and you should see the output ...

a =

     1


b =

     1     2     3     4


c =

     1     4     7    10    13    16    19    22


d =

         0    0.2000    0.4000    0.6000    0.8000    1.0000


e =

    10
    20
    30


  ... which is precisely what you would see if you entered the 
  five statements (the comment line doesn't count) in myscript.m 
  interactively

o And executing a Matlab script is as easy as that!

o Now it's your turn ...

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EXERCISE 1:
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o Download  ...

http://laplace.phas.ubc.ca/210/Labs/matlab-ex1.pdf

... also available via the Syllabus section: MATLAB Exercises 1 [PDFl],
and follow the instructions.

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EXERCISE 2:
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o Add the following bash alias to your ~/.aliases file, so that 

  alias mat='matlab -nodesktop -nosplash'

o Again, it is best to make an explicit backup of ~/.aliases before you
  modify it.  For example

% cd 
% cp .aliases .aliases.O

o Once you've added the alias, test it by starting a new terminal session 
  and typing  ...

% mat

  ... to ensure that command line Matlab *does* start

o Ask for help as necessary