Lab01, CISC106, Fall 2007

Goals

By the time you complete this lab, you should be able to:

1. Log on to a Sun Ray terminal
2. Start up both MATLAB and a web browser (Firefox)
3. Type in basic commands into MATLAB and see their effect
4. Save a sequence of MATLAB commands into a file (a so-called "dot-M" file)
5. Run an existing .m file
6. Use the diary command to save your work into a file you can submit for grading
7. Submit your saved work for grading using "MyCourses" (also known as WebCT).

You might not get through all of this today, and if so that's ok—you'll have some more time in next week's lab to finish this up. But many students last year were able to finish within one 50-minute lab period.

In any case, get as much done as you can this week, because there will be additional stuff to do next week.

Step-by-Step Instructions

Step 1: Logging on to the Sun Ray

The most up-to-date instructions for doing this are available at the following link

https://www.phillconrad.org/cisc106/Wiki.jsp?page=CISC106_Accessing_MATLAB_on_strauss

Here is a "snapshot" of those instructions, provided for your convenience.

What about starting up the web browser?

On the applications menu (the same one you used to start up MATLAB) you should find a menu item called "Internet", and under that, an item called "Web Browser" (or something like that). Select that option to start up Firefox. At the bottom of your screen, you'll see tabs that you can click on to move back and forth between the web browser and the MATLAB window.

Now, if you are working from a printed copy of these instructions,
find this page in the web browser window.

Enter the address for the course web page: http://www.udel.edu/CIS/106/pconrad

Then, find the current semester, and click on labs, then on lab01.html.

You should then be looking at a copy of this page in the web browser. If not, ask your TA for assistance.

Step 3: Type some basic commands into MATLAB and see their effect

The following exercises are designed to get you comfortable with the MATLAB environment. For now, we'll do all our work in the Command Window part of the MATLAB environment.

First, let's calculate the value of 5 squared. Type it in and hit "return" (or "enter").

>> 5^2

You should get the following result:

 ans = 
                    25

Now, use MATLAB calculate the area of a circle of radius 6. Try typing this into the command window:

>> area = pi * 6^2

You should get the following result:

area =

  113.0973

>> 

Now try typing the following:

>> x = cos(pi);

If you put the semicolon (;) on the end, then MATLAB will print nothing in response except the symbol >>, which is called the prompt. The prompt is where you type input into the MATLAB Command Window.

But what you have done is to assign a value to a MATLAB variable called x. The value of x can be shown by just typing the letter x by itself on the command line, like this:

>> x

The result should be something like this:

x =

    -1

>> 

In the days and weeks to come, as you read the text and learn more about MATLAB in lecture, you'll have a lot more things to type in here. For today, it is enough that you know how to find the MATLAB command window, and what it means to "type something in and get a response."

Step 4: Save a sequence of MATLAB commands into a file (a so-called "M-file" file)

A sequence of MATLAB commands can be saved in a so called "M-file". An M-file is called an "M-file", because it has a name that ends in ".m", such as:

• plotResults.m
• calculateAnswer.m
• labReport.m
• etc...
  

To create a new .m file, choose "File"/"New"/"M-file". This will open a window where you can begin to type commands. Be patient—it may take several seconds for the new window to open!

Into this window, type the following. Where it says "insert your name here", put your full name. DON'T put your student id number---just your first and last name is sufficient!

% lab01.m  by (insert your name here)
% Calculate the area of a circle and display the result

radius = 6;
area = pi * 6 ^ 2;
fprintf('The area of the circle is %f\n',area);

When  you are finished, use the Save As command from the File menu to save the file with the name lab01.m

The filename is entered at the bottom of the window, as shown in the illustration below 

Step 5: Run an existing .m file

To run an existing .m file, just type the name of the file. For example, try typing

>> lab01

You should see output like the following:

The area of the circle is 113.097336
>>

If so, you are finished with this step! If you have difficulty, then ask your TA for help.

Step 6: Use the diary command to save your work into a file you can submit for grading

In the command window, type

>> diary lab01.txt

This turns on a record of what you type in MATLAB. Then type these three commands:

>> type lab01.m
[a listing lab01.m will appear here]
>> lab01
[the output from lab01 will appear here]
>> diary off

You should now have files in your account called lab01.m and lab01.txt. In the next step, you will submit these two files for grading by your TA.

Step 7: Submit your saved work for grading using "MyCourses" (also known as WebCT).

The following web site describes how to log on to MyCourses.

Note that although you can log on to MyCourses (also known as WebCT) from any web browser, in order to submit the work you do in MATLAB, you need to be on one of the SunRays on the UD campus so that you can get at the files lab01.m and lab01.txt

Log on to MyCourses (WebCT) and find CISC106 (if it is not listed, tell your TA, and email your instructor!)

Follow the instructions for submitting an Assignment in WebCT (submit this as lab01). You should submit two files:

1. lab01.m
2. lab01.txt

And you are all finished with lab01. Now you can begin your study of MATLAB in detail, as explained below, by reading Chapter 1, and then working through Chapter 2.

Next steps

So, your next steps is to read through Chapter 1 and Chapter 2 in your Holly Moore text, and most importantly, to work through the material in Chapter 2 while actually sitting at a computer with MATLAB in front of you. Chapter 1 can be read without a computer around, but Chapter 2 is designed to be read with MATLAB there.

You should also read Section 7.2, titled "Output Operations". This section describes two ways to get output in MATLAB, namely disp and fprintf. These are very useful, so we are going to cover them earlier than the sequence indicated in the book. Don't worry about reading this section out of order—section 7.2 doesn't contain any material that isn't already covered by the end of Chapter 2.

For now, you'll probably want to use a SunRay to access MATLAB. SunRay terminals are found in Willard 009B, but that room is typically in use for various computer labs during the week. You can also find SunRay terminals in the basement of Smith Hall. In lecture, we'll talk about you you can also access MATLAB on "strauss.udel.edu" from any PC or Mac with Internet access. There will still be some features of MATLAB that you'll only be able to do on a SunRay, but most features you'll be able to do from anywhere.

End of lab01 for CISC106, Fall 2007 (50 pts)