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Interduction to MATLAB
•Manal AlotaibiMathematics departmentCollege of science King saud university
Content
MATLAB
What is MATLAB?The MATLAB desktop invironment.MATLAB as calculator.Variables.AlgorithmInterduction to m-file function.
Outline
MATLAB
What is MATLAB?The MATLAB desktop invironment.MATLAB as calculator.Variables.AlgorithmInterduction to m-file function.
• MATLAB is a mathematical and graphical software package with numerical, graphical and programming capabilities.
• it has built-in functions to perform many operations.
MATLAB
Outline What is MATLAB?The MATLAB desktop invironment.MATLAB as calculator.Variables.AlgorithmInterduction to m-file function.
MATLAB
MATLAB
Command window: Type your instructions here and press
ENTER to execute them.
MATLAB
Example: Declare a column matrix withvalues 1,2 and 3.
MATLAB
Command history: a list of instructions executed by MATLAB is shown here .
MATLAB
Workspace: shows a list of variables created by MATLAB.
As you can see, the value of ‘aaa’is shown .
MATLAB
Another way to create a variable Is to press this button .
MATLAB
MATLAB will prompt you to enter the variable name .
MATLAB
As you can see, the variable name has been changed to bbb .
MATLAB
To assign a value to bbb, you can do it intwo ways: 1) Using the command window.
2 )Or by double clicking on bbb .
MATLAB
To clear all variables from memory and close all
figures, use the clear, close all command.
MATLAB
As you can see, all workspace variables are deleted when you execute this command.
MATLAB
To clear the command window,use the clc (clear console) command.
MATLAB
As you can see, all console entries are deleted when
you execute this command.
MATLAB
If you want to see help,you can type help at the
command window.
MATLAB
Outline
What is MATLAB?The MATLAB desktop invironment.MATLAB as calculator.Variables.AlgorithmInterduction to m-file function.
MATLAB
Operators
•addition + a+b•subtraction-a-b•multiplication*a*b•Division(left) / a/b•Division(right)\ a\b (ba)•power^a^b
MATLAB
Operator precedence rules
1. () parentheses.2. ^ power.3. - negation.4. */ \ all multiplication and division.5. + - addition and subtraction.
MATLAB
Examples >>6*5
ans= •30 >>17/5
ans= 3.4000
>>ansans=
3.4000
>>6*5ans= •30 >>17/5
ans= 3.4000
>>ansans=
3.4000
>> x=6*5x=
30>> y=17/5;>> yy=
3.4000>> z=x+yz=
33.4000>> whoYour variables are:x y z
>> x=6*5x=
30>> y=17/5;>> yy=
3.4000>> z=x+yz=
33.4000>> whoYour variables are:x y z
MATLAB
Some functions in MATLAB• exp(x) ex
• sin(x) sin x• asin(x) sin-1x• log(x) ln x• log10(x) log x• sqrt(x)• abs(x) |x|• sum(x) ix
• pi p• i,j imaginary unit• NaN Not-a-Number• Inf
MATLAB
Example
y x>>y=x^0.5;>>y=x^(1/2);>>y=sqrt(x);
MATLAB
Outline
What is MATLAB?The MATLAB desktop invironment.MATLAB as calculator.Variables.AlgorithmInterduction to m-file .
MATLAB
Variables Creating Variables:
– Names • Can be any string of upper and lower case letters along with numbers
and underscores but it must begin with a letter• Reserved names are IF, WHILE, ELSE, END, SUM, etc.• Names are case sensitive
– Value• This is the data the is associated to the variable; the data is accessed by
using the name.– Variables have the type of the last thing assigned to them• Re-assignment is done silently – there are no warnings if you overwrite
a variable with something of a different type.
MATLAB
Outline
What is MATLAB?The MATLAB desktop invironment.MATLAB as calculator.Variables.AlgorithmInterduction to m-file
MATLAB
Definition of algorithm
• An algorithm is the sequence of steps needed to solve a problem.
MATLAB
Outline
What is MATLAB?The MATLAB desktop invironment.MATLAB as calculator.Variables.AlgorithmInterduction to m-file .
MATLAB
To create an m-file, 1) type edit at the command window, or
2 )Press this button.
MATLAB
The previous command willdisplay the editor window.
The editor creates an m-filethat can be used to write
your MATLAB programs .
MATLAB
To execute a program, pressthe RUN button.
MATLAB
End the first part
