Page 821 - Mechatronics with Experiments

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MATLAB , SIMULINK , STATEFLOW, AND AUTO-CODE GENERATION 807
it more convenient and easy to code the event driven nature of logic. Many examples are
provided under the
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MATLAB > Help > Demos
menu with example categories in automotive, aerospace, and heating systems.
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The main benefit of the MATLAB /Simulink environment over the standard high
level programming languages such as C/C++ are:
1. faster program development due to reduced detail in defining data structures (i.e.,
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in MATLAB , we do not have to declare data types before usage) and easy to use
library functions (including I/O functions),
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2. good graphical communication of the model structure in Simulink and Stateflow as
oppose to text based programming language description,
3. auto-code generation tools for real-time implementation.
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In addition, the MATLAB /Simulink environment can interface with external user
written C functions. However, use of external functions should be balanced with the diffi-
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culty they impose and maintaining the advantages of the MATLAB environment.
MATLAB ® is started by double clicking on the MATLAB ® short-cut icon on the
desktop under Windows development environment. The standard prompt of MATLAB ®
when it starts and opens its user interface window, called the “Command Window”,is
>>
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The user interacts with MATLAB from the command window. In addition, the window
has menu items which will allow the user to perform typical file I/O, print, and setup
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operations, and get help on any MATLAB topic.
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The MATLAB development environment has seven basic windows. Each window
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is dockable and can be disconnected from the MATLAB window and treated as a separate
window. Each window can be opened/closed using the View menu check mark next to each
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window. MATLAB ’s user interface is modified in each version a little bit. The current
version may have a slightly different user interface than described here.
The main windows are (Figure A.2):
1. Command Window: the window through which the user enters MATLAB ® com-
mands interactively.
>> clc ; % Clears the screen of the Command Window.

2. Command History Window: used to store and reuse previously used interactive
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MATLAB commands. It is useful during program debugging.
3. Workspace Window: this window shows all of the variables defined in the MATLAB ®
workspace and their values.
>> clear ; % Clears (deletes) all data variables defined from the
MATLAB® Workspace.
>> who ; % Displays the currently defined data variables
% (without their size info) in the MATLAB® Workspace.
>> whos ; % Displays the currently defined data variables
%(with their size info) in the MATLAB® Workspace.
4. Current Directory Window: directory navigation window. Using the icons on this
window, the user can quickly change the current directory. By default, MATLAB ®