1.
What is MATLAB?
· MATrix LABoratory
· Interpretive Language
· Basic data structure is a matrix
2.
Programs and Functions
· Command Session : run command after command
· Function = .m file : variables in and variables out
· Script File = .m file : program (set of instructions)
3.
What can you do?(EE311 /
EE312)
· Circuits, Electronics, Systems, Communication, Antennas, etc.
· Very powerful plotting routines
· Many useful .m files and functions
4.
Logging On and Creating
a Folder
· To log on, press ‘Ctrl-Alt-Delete’
· Enter your ‘username’ and ‘password’, then click on ‘OK’
· To create a folder, Double-click on the icon in the upper left hand corner
· Double-click on your U:\ Drive (username on ‘megatera’ U:’)
· Pull down ‘File’, go to ‘New’ and then to ‘Folder’
· Name your ‘New Folder’ (eg. M_demo). Click on folder icon
5.
Starting Internet
Explorer and Downloading a demo
· Click on the Internet Explorer Icon next to start (second icon from the left)
· Click on link ‘College of Engineering’,
· Then click on ‘Electrical and Computer Engineering’
· Click on ‘Curriculum’, go to ‘Courses’
·
Scroll down to and click on ‘EE
311 Linear Systems Analysis I’
· Click on ‘Computer Labs’ and then on ‘ Computer Lab #1 …’
· Click on ‘LAB NOTES’ and then on ‘Lab Notes For Computer Lab 1.doc’, Scroll thru to see pretty pictures.
· Use back arrow to return to ‘Lab Notes and Demos’, click on ‘rootdemo.m’
· A window will pop up. Click ‘OK’ to save the file
· From here, double-click on ANDERxxx(username), then on your U:\ Drive
·
Double-click on the folder you just created and click
on ‘Save’. Then close.
6.
Starting MATLAB and
Running m-files
· Open ‘Start’, go to ‘Engineering Applications’ and then to ‘MATLAB R12’
· Click on ‘Current Directory’ tab, Maximize window size.
· Click on ‘d:\matlabR12\work’, type ‘u:\’ and press ‘Enter’
· Double-click on your new folder (eg. M_Demo)
· Go to the command window (when you see ») on the right and type ‘rootdemo’ to run the program
· To run another file, click on the tab ‘Lab Notes and …” on the bottom of the screen
· Download another file to your directory (eg. ‘app_expj.m’) Click on ‘OK’, ‘Save’, and then ‘Close’
· Go back to MATLAB and type ‘app_expj’ (underneath where you typed ‘rootdemo’)
7.
Program Exercise 1: Digital Oscilloscope: vs. t
· Use the command window [ » ] to create a signal
· Need digital time base:
· In MATLAB, this is coded as:
»f=440; % musical note A
»t=[0:0.01/f:4/f]; % 100 samples per period & 4
periods
» x=sin(2*pi*f*t);
»figure %
creates a new figure
»plot(t,x) %
Shown below
8. Program Exercise 2: Complex Frequency Response of an Audio Amplifier: .
· Create your own function, an m-file
· Need frequency base: % 10 zero crossings
· Click on ‘File’, go to ‘New’, and then to ‘M-file’. In this editor, type
function plotSINC(T)
% plot complex frequency response of audio amplifier
% H(f)=T*sin(pi*f*T)/(pi*f*T) for roughly
% 5 bandwidths worth of frequency
f_limit=5/T;
f_step=.1/T;
f=[-f_limit:f_step:f_limit]; % create frequency vector in units of hertz
H_f=T*sinc(f*T); % sinc is built-in to MATLAB
figure % plot results
title('Complex Frequency Response of an Audio
Amplifier')
hold on
axis([-f_limit f_limit -.3*T T])
plot(f,H_f)
plot([-f_limit f_limit],[0 0],'k')
xlabel('\it{f}'), ylabel('{\it{H}} ( {\it{f}} )')
· Go to ‘File’, click on ‘Save’, label file as ‘plotSINC’.
· Click on MATLAB on the bottom of screen
· For T = 2, we would type the following (shown below):
» plotSINC(2)