MATLAB Instruction manual

 

What is MATLAB?

 

The name MATLAB stands for “MATrix LABoratory” and was originally designed as a tool for doing

numerical computations with matrices and vectors. It has since grown into a high-performance language

for technical computing. MATLAB, integrating computation, visualization, and programming in an easyto-

use environment, allows easy matrix manipulation, plotting of functions and data, implementation of

algorithms, creation of user interfaces, and interfacing with programs in other languages. Typical uses

include:

 

• Math and Computation

 

• Modeling and Simulation

 

• Data Analysis and Visualization

 

• Application Development

 

• Graphical User Interface development

Window Layout:

The first time you start MATLAB, the desktop appears with the default layout, as shown in Figure 1.

The following tools are managed by the MATLAB desktop:

• Command Window: Run MATLAB statements.

• Current Directory Browser: To search for, view, open, find, and make changes to MATLAB

related directories and files, use the MATLAB Current Directory browser.

• Command History: Displays a log of the functions you entered in the Command Window, copy

them, execute them, and more.

• Workspace Browser: Shows the name of each variable, its value, and the Min and Max calculations,

which MATLAB computes using the min and max functions, and updates automatically.

In case that the desktop does not appear with the default layout, you can change it by the menu

Desktop ! Desktop Layout ! Default.

The desktop includes these panels:

Current Folder - This panel allows you to access the project folders and files.

Command Window - This is the main area where commands can be entered at the command line. It is indicated by the command prompt (>>).

In order to run the program, type the name of the file containing your program at the prompt. When typing the filename in the command window do not include ". m". By pressing enter, MATLAB will run your program and perform all the commands given in your file.

Workspace - The workspace shows all the variables created and/or imported from files.

 To open the Workspace browser, select Workspace from the Desktop menu in the MATLAB desktop, or type workspace at the Command Window prompt. The Workspace browser opens. The Workspace browser shows the name of each variable, its value, its array size, its size in bytes, and the class.

 Command History - This panel shows or rerun commands that are entered at the command line.

 

You are now faced with the MATLAB desktop on your computer, which contains the prompt

(>>) in the Command Window. Usually, there are 2 types of prompt:

>>For full version

EDU> for educational version

 

 

Note:

1. To simplify the notation, we will use this prompt, >>, as a standard prompt sign, though our MATLAB version is for educational purpose.

2. MATLAB adds variable to the workspace and displays the result in the Command Window.

 

Managing workspace and file commands Command	Description
cd	Change current directory
clc	Clear the Command Window
clear (all)	Removes all variables from the workspace
clear x	Remove x from the workspace
copy file	Copy file or directory
delete	Delete files
dir	Display directory listing
exist	Check if variables or functions are defined
help	Display help for MATLAB functions
look for	Search for specified word in all help entries
mkdir	Make new directory
move file	Move file or directory
pwd	Identify current directory
rmdir	Remove directory
type	Display contents of file
what	List MATLAB files in current directory
which	Locate functions and files
who	Display variables currently in the workspace
whos	Display information on variables in the workspace

 Commonly used Operators and Special Characters

 

MATLAB supports the following  commonly used operators and special characters: MATLAB supports the following  commonly used operators and special characters: Operator              Purpose                         + Plus; addition operator. - Minus; subtraction operator. * Scalar and matrix multiplication operator. .* Array multiplication operator. ^ Scalar and matrix exponentiation operator. .^ Array exponentiation operator. \ Left-division operator. / Right-division operator. .\ Array left-division operator. ./ Array right-division operator. : Colon; generates regularly spaced elements and represents an entire row or column. ( ) Parentheses; encloses function arguments and array indices; overrides precedence. [ ] Brackets; enclosures array elements. . Decimal point. … Ellipsis; line-continuation operator , Comma; separates statements and elements in a row ; Semicolon; separates columns and suppresses display. % Percent sign; designates a comment and specifies formatting _ Quote sign and transpose operator. ._ Non-conjugated transpose operator. = Assignment operator.

 

Naming Variables

Variable names consist of a letter followed by any number of letters, digits or underscore.

MATLAB is case-sensitive.

Variable names can be of any length; however, MATLAB uses only first N characters, where N is given by the function namelengthmax.

 

Saving Your Work

The save command is used for saving all the variables in the workspace, as a file with .mat extension, in the current directory.

For example, save myfile

You can reload the file anytime later using the load command.

load myfile .