Lecture 1: Matlab Universe
Tom Rebold
ENGR 52
Course Overview
The Way the Class Works
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I lecture for 15 – 20 minutes
You do lab for 30 – 40 minutes
Labs link to extra Problems online for fast
students
Everyone turn in a solution to the last
problem they solve today
HOMEWORK: Bring in 3 Math problems to
solve…medium, hard, impossible
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We’ll have independent study time
To Buy Matlab
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Student Version, $100
Can purchase, download online
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Link from ENGR196.3 class webpage
Bookstore does not stock
MATLAB retails for $1600, so it’s a pretty
good deal
BETTER DEAL: FreeMAT !!
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Open source version, powerful, free, legal
Why MATLAB
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10x faster compared to other choices:
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C++, Fortran, Java
Excel, MathCad, Mathematica, Labview
Matlab is a Very High Level Language
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Designed for complex numerical calculations
Vast array of Toolboxes for different specialties
Excellent visualization tools
Symbolic math somewhat awkward
Simulink for modelling dynamic systems, 10x faster still
Today’s Agenda
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MATLAB Overview
Working in MATLAB’s Environment
Simple calculations, variables
MATLAB’s ENVIRONMENT
Download week1.zip
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Follow instructions in Lab1
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View toolbox demos
Experiment with workspace configuration
Numeric Data
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At it’s most basic level, Matlab can be used
as a simple calculator, by typing in an
arithmetic expression and hitting enter. For
example, at the command prompt, type:
>> 8/10
>>4 * 3
>>8/10 + 4*3
>>9^2
(what does the ^ operator do? )
Arithmetic rules of precedence
>> 8 + 3*5
>> 8 + (3*5)
>> (8 + 3) * 5
>> 4^2 – 12
>> 8/4*2
>> 8/(4*2)
>> 3*4^2
>> (3*4)^2
>> 27^(1/3)
>> 27^1/3
built in functions
Matlab has hundreds of built in functions to
do more complicated math
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sqrt(9)
log10(1000)
log(10)
pi
cos(pi)
i
exp(i*pi)
Variables
Usually we need to hang on to the result of
a calculation
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We need a way to name memory for storage
Variable--name of a place in memory where
information is stored
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r = 8/10
r
s=20*r
score = 4 * r + s
z = sqrt(1000)
z = sqrt(s)
Assignment Operator
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=
means “gets”
Translation:
MATLAB: r = 8/10
ENGLISH: r “gets” the value 8/10
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OK in Math
x + 2 = 20
NOT OK IN MATLAB !!
(only variable on Left Side)
Expressing Math in MATLAB
2
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yx
x-y
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3x
2y
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Saving Work in Matlab Script (.m) files
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You’ll want to build up complex calculations
slowly
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Try, correct, try again, improve, etc
.m Files store your calculations
Can be edited in Matlab
Can be re-executed by typing the file name
Example .m file
Volume of a Cylinder. The volume of a cylinder
is V= pr2h. A particular cylinder is 15 meters high
with a radius of 8 meters. We want to construct
another cylinder tank with a volume 20% greater,
but with the same height. How large must its
radius be?
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The session follows:
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r = 8;
h = 15;
V = pi*r^2*h
V = V + 0.2*V
r = sqrt(V/ (pi * h))
Put this in a file called
cyl_volume.m
to save retyping
 adds 20% to V
Solve some problems!
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Pick any problem, solve it and print your
solution .m file
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Write name, turn in
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You may wish to save your class .m files on
a USB drive