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Numerical Analysis Lab
Introduction To Matlab
LAB 1
INTRODUCTION TO MATLAB-1
1.0
OBJECTIVE


2.0
To understand basic function of MATLAB,
To write inline functions
INTRODUCTION
MATLAB is a high-performance language for technical computing. It integrates
computation, visualization, and programming in an easy-to-use environment where
problems and solutions are expressed in familiar mathematical notation. Typical uses
include
 Math and computation
 Algorithm development





Data acquisition
Modeling, simulation, and prototyping
Data analysis, exploration, and visualization
Scientific and engineering graphics
Application development, including graphical user interface building
MATLAB is an interactive system whose basic data element is an array that does not
require dimensioning. This allows you to solve many technical computing problems,
especially those with matrix and vector formulations, in a fraction of the time it would
take to write a program in a scalar noninteractive language such as C or Fortran.
The name MATLAB stands for matrix laboratory. MATLAB was originally written
to provide easy access to matrix software developed by the LINPACK and EISPACK
projects. Today, MATLAB engines incorporate the LAPACK and BLAS libraries,
embedding the state of the art in software for matrix computation.
MATLAB features a family of add-on application-specific solutions called toolboxes.
Very important to most users of MATLAB, toolboxes allow you to learn and apply
specialized technology. Toolboxes are comprehensive collections of MATLAB functions
(M-files) that extend the MATLAB environment to solve particular classes of problems.
Areas in which toolboxes are available include signal processing, control systems, neural
networks, fuzzy logic, wavelets, simulation, and many others.
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Numerical Analysis Lab
Introduction To Matlab
a) Getting Started With MATLAB
Starting MATLAB
On Windows platforms, start MATLAB by double-clicking the MATLAB
shortcut icon on your Windows desktop. If you have worked in MATLAB before and
have an M-file that was written by MATLAB, you can also double-click on the file to
lunch MATLAB
MATLAB windows
On almost all systems, MATLAB works through three basic windows.

Command window
This is the main window. It is characterized by the MATLAB command prompt
‘>>’. When you launch the application program, MATLAB puts you in this
window. All commands, including those for running user-written program, are
typed in this window at the MATLAB prompt.
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Numerical Analysis Lab
Introduction To Matlab
Lunch Pad
This subwindow lists all MATLAB related applications and toolboxes that are
installed on your machine. You can launch any of the listed applications by
double clicking on them.
Workspace
This subwindow lists all variables that you have generated so far and shows their
type and size. You can do various things with these variables, such as plotting, by
clicking on a variable and then using the right button on the mouse to select your
option.
Command History
All commands typed on the MATLAB prompt in the command window get
recorded, even across multiple sessions. You can select a command from this
window with the mouse and execute it in the command window by double
clicking on it. You can also select a set of commands from this window and create
an M-files with right click of the mouse.
Current History
This is where all your files from the current directory are listed. You can do file
navigation here. You also have several options. To see the options, click the right
button of the mouse after selecting a file. You can run M-files, rename them,
delete them, etc.

Graphics window
The outputs of all graphics command typed in command window are flushed to
the graphics or Figure window. The user can create as many figure windows as
the system memory will allow.
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Numerical Analysis Lab

Introduction To Matlab
Edit window
This is where you write, edit, create, and save your own programs in files
‘M-files’.
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Numerical Analysis Lab
Introduction To Matlab
b) Basic Functions of MATLAB
General function you should remember
who
whos
save
load
clear
pack
size
length
disp
clc
home
format
echo
more
Managing Variables and the Workspace
list current variables
list current variables, long form
save workspace variables to disk
retrieve variables from disk
clear variables and functions from memory
consolidate workspace memory
size of matrix
length of vector
display matrix or text
Controlling the Command Window
clear command window
send cursor home|to top of screen
set output format
echo commands inside script commands
control paged output in command window
Matrix Operators
+
−
*
^
/
\
‘
.'
Array Operators
addition
subtraction
multiplication
power
right division
left division
conjugate transpose
transpose
5
+
−
.*
.^
./
.\
addition
subtraction
multiplication
power
right division
left division
Numerical Analysis Lab
Introduction To Matlab
Relational and Logical Operators
<
less than
<=
less than or equal
>
greater than
>=
greater than or equal
==
~=
equal
not equal
Special Characters
=
[]
()
.
..
...
,
;
%
:
assignment statement
used to form vectors and matrices; enclose multiple function output variables
arithmetic expression precedence; enclose function input variables
decimal point
parent directory
continue statement to next line
separate subscripts, function arguments, statements
end rows, suppress printing
comments
subscripting, vector generation
Example 1
Compute the following quantities

1
25
and (1  5 ) 1
5
2
2 1
>> 2^5/(2^5-1)
ans =
1.0323

3
5 1
( 5  1) 2
1
>> 3*(sqrt(5)-1)/(sqrt(5)+1)^2-1
ans =
-0.6459
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Numerical Analysis Lab
Introduction To Matlab
Example 2

Create a vector A containing the integers 1 through 5
>> A=1:5

Create a vector A [1.0 1.1 1.2 1.3 1.4]
>> A=1:0.1:1.4
Example 3
Colon operator
 >> c=[1 2 3; 4 5 6; 7 8 9];
>> y=c(:,3)
y=
>> z=c(2,:)
>> x=c(:,2:3)
z=
x=
4
3
6
9
5
2
5
8
6
3
6
9
Example 4
Element by element operation matrices
>> a=[1 2 3 4];
>> b=[4 3 2 1];
>> c=a+b
>> e=a.*b
e=
c=
5
4
5
5
6
>> f=a./b
d=
f=
-1
1
4
5
>> d=a-b
-3
6
3
0.2500
7
0.6667
1.5000
4.0000
Numerical Analysis Lab
Introduction To Matlab
c) Creating and Using Inline Function
A mathematical function, such as F(x) or F(x,y), usually requires just values of
the independent variables for computing the value of the function. We frequently need to
evaluate such functions in scientific calculations. However, there is a quicker way of
programming function is they are not too complicated. This is done by defining inline
functions – functions that are created on the command line.
We define these functions using the built-in function inline. The syntax for
creating an inline-function is particularly simple:
F=inline (‘function formula’)
Thus, a function such as F(x) = x2sin(x) can be coded as
F = inline(‘x^2*sin(x)’)
For more examples and usage of inline functions we can as below:
Example 1
Compute the following quantities
f ( x)  x 2  sin x where x = π

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Numerical Analysis Lab
Introduction To Matlab
where x = 0, π/4, π/2, 3π/4, π

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