Chapter 2:

Getting Started with MATLAB

MATLAB for Scientist and Engineers

Using Symbolic Toolbox

2

You are going to

Familiarize yourself with MATLAB desktop, See how simple it is to use MATLAB, yet power-

ful, Express simple math expressions in MATLAB

tongue, Solve mathematical problems using MATLAB, And finally, be glad to know MATLAB is with you.

3

Starting MATLAB

Start – All Programs – MATLAB – R2009b … Create your own work space.

Customize the startup script.

Create a new folder under c:\c:\workM

edit 'startupsav.m' save as 'startup.m'

startup.m

cd c:\workMdisp(['MATLAB v' version]);

4

Overview of MATLAB Desktop

Command Window

Editor Workspace

Command HistoryWindow

Current Folder

ContentBrowser

Show how to use Desktop.

5

Test Ride of MATLAB: bench

Type bench in the command window.

6

Getting Started with MATLAB

Through the demonstration, you will be able to do simple arithmetic operations generating arrays using : operator disable output using ; entering matrices use help systems display the size of matrices perform matrix operations selecting part of matrices plotting matrices

Show demo: getting_started_with_matlab.m

7

Working in the Desktop

Through the demonstration, you will be able to calculate values for a function plot the results edit the previous commands display the variables using whos modify variables directly using variable editor plot data at workspace browser save and load part / all of the variable adjusting window layouts docking/undocking

Show demo: working_with_ide.m

8

Match the pairs.

Quiz: MATLAB Windows

Main window, enters variables,runs programs.

Logs commands entered in the Command window.

Shows the files in the current di-rectory.

Creates and debugs script and function files.

Command Window

Editor Window

Command HistoryWindow

Workspace Window

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MATLAB is a Very Good Calculator!

Write down the answers.

-4 + 7 * ( 2 - 5 ) / 3.14-4 + 7 * ( 2 - 5 ) / 3.14 7 2 5

43.14

2^3 - sqrt(25) + exp(3)2^3 - sqrt(25) + exp(3)3 32 25 e

2.51e3 + 2/3*pi2.51e3 + 2/3*pi3 1

2.51 10 23

Mathemati-cal

Expres-sions

MATLABExpres-sions

YourAnswers

(2+3*i)*(1-2*i)^2(2+3*i)*(1-2*i)^2 2(2 3 ) 1 2i i

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Basic Math Expressions

2.1+3 cos log round nchoosek min

98-3.2 acos log10 rem besselj max

-67*34 cosd sqrt mod beta size

81/8 acosd abs factor erf primes

7.1^4 cosh angle isprime erfc gcd

1.2e3 acosh conj primes gamma lcd

3+4*i tan imag gcd legendre mean

pi atan2 real lcm factorial roots

eps asin floor rat sum poly

exp asind ceil perms prod conv

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Exercise: Math Expressions Evaluate the following expressions when x = 1.25

2 3310log x x

34 tan ln6

xx x e

2

3

sin ( / 6)23 2010

9 652x

>>

>>

>>

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Exercise: Geometry

Find the volume of the oil tank below.

MATLAB ExpressionMATLAB Expression

20m

ANSANS

24m

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Variables

Assign the results into variables.

x = 3^4 + 27^(1/3)x = 3^4 + 27^(1/3)4 33 27x

y = (2+3i)*(1-2i)y = (2+3i)*(1-2i)(2 3 )(1 2 )y i i

z = sqrt( x^2 + y^2 ) ;z = sqrt( x^2 + y^2 ) ;2 2z x y

Do not print the answer!Do not print the answer!

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Workspace Variables

Variables live in the MATLAB workspace.

>> x = 3^4 + 27^(1/3)x = 84>> y = (2+3i)*(1-2i);>> z = sqrt( x^2 + y^2 );>> who

Your variables are:

ans x y z >> clear>> who>>

>> x = 3^4 + 27^(1/3)x = 84>> y = (2+3i)*(1-2i);>> z = sqrt( x^2 + y^2 );>> who

Your variables are:

ans x y z >> clear>> who>>

whowho

who a*who a*

whoswhos

clcclc

List variable names.List variable names.

List variable names be-

ginning with a.

List variable names be-

ginning with a.

List variable in long

format.

List variable in long

format.

Clear command window.Clear command window.

clearclear Clear variables from

memory.

Clear variables from

memory.helphelp docdoc

whatwhat

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Exercise: Geometry & Trigonometry

Find the distance between C2 and C4.

1C

2C

3C

4C

1

2

3

4

16

6.5

12

9.5

R mm

R mm

R mm

R mm

a

b

c

2 2 2 2 cosc a b ab

Hint: Use the following identity.

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Exercise: Your Solution

Mathematical Expressions

MATLAB Expressions

Your Answer:

17

Key Takeaways

Now, you know how to customize the MATLAB startup script. use the MATLAB desktop windows. change the layout of the desktop windows. evaluate mathematical expressions.

18

Q & A