1. Engineering Computation using MATLAB
Welcome to Chapter 1 of Matlab for Engineers. In this chapter we’ll introduce you to the Matlab computer software program
Dr Simin Nasseri,
Mechanical Engineering Technology Department,
Southern Polytechnic State University

2. Matlab MATLAB stands for Matrix Laboratory
Developed primarily by Cleve Moler in the 1970's
MATLAB was originally written in Fortran, then later rewritten in C.
Derived from FORTRAN subroutines LINPACK and EISPACK, linear and eigenvalue systems.
Rewritten in C in the 1980's with more functionality, which include plotting routines.

3. Matlab
MATLAB is one of a number of commercially available, sophisticated mathematical computation tools
Others include
Maple
Mathematica (MATLAB's competitor = the symbolic computation program)
MathCad
MATLAB is more convenient for numerical analysis and linear algebra. It is frequently used in engineering community.
Mathematica has superior symbolic manipulation, making it popular among physicists.
We’ll take a look at what the software can do, introduce the student edition of Matlab, and we’ll look at some examples of how Matlab is used in industry. Finally, we’ll introduce a problem solving strategy that is commonly used in science and engineering.

4. Why Matlab?!
MATLAB is a high-performance language for technical computing.
It integrates computation, visualization, and programming environment.
MATLAB is a modern programming language environment: it has sophisticated data structures, contains built-in editing and debugging tools, and supports object-oriented programming.
These factors make MATLAB an excellent tool for teaching and research.

5. Why Matlab?! MATLAB is widely used. MATLAB is easy to use.
MATLAB is interpreted (not compiled), errors are easy to fix.
MATLAB is optimized to be relatively fast when performing matrix operations.

6. Why Matlab?!
A systematic problem solving strategy makes it more likely you’ve found the right answer.
Built in programming language (Matlab is a package + a language).
Not a general purpose language like C++ or Java.
Matlab Excels at Numerical calculations (Especially involving matrices) and Graphics.

7. Weaknesses
MATLAB is not a general purpose programming language such as C, C++, or FORTRAN.
MATLAB is designed for scientific computing, and is not well suitable for other applications.
MATLAB commands are specific for MATLAB usage. Most of them do not have a direct equivalent with other programming language commands.

8. Summary
MATLAB® is a high-level language and interactive environment that enables you to perform computationally intensive tasks faster than with traditional programming languages such as C, C++, and Fortran.
Introduction and Key Features
Developing Algorithms and Applications
Analyzing and Accessing Data
Visualizing Data
Performing Numeric Computation
Publishing Results and Deploying Applications

9. Matlab 2010
The MathWorks Inc. was created (1984) to market and continue development of MATLAB.
MATLAB is updated regularly.
The Mathworks packages their software in groups, called releases.
Each one contains:
MATLAB
Simulink
A number of specialized “toolboxes”
1. Matlab is published by a company call the Mathworks. Their software is usually packaged in groups, called releases.
2. This text refers to release 14, which includes Matlab 7, Simulink – which is a companion program used to model dynamic systems - and a number of specialized toolboxes. Toolboxes are groups of functions unique to certain industries or tasks. For example there is a data analysis toolbox with expanded capability past what ships with a standard Matlab installation. These toolboxes are sold separately.

10. New Release Naming System
They will be issuing updates twice a year
R2010a
R2010b
MATLAB comes in both a student and professional edition.
Student editions are available for:
Windows Operating Systems
Mac OS
Linux

11. How is MATLAB used in Industry?
Widespread, especially in the signal processing field
Tool of choice in Academia for most engineering fields
Some examples….
Matlab is widely used both in industry and in academia. It has found particularly wide acceptance in the signal processing field, and so is very common in Electrical engineering departments in colleges and universities. However, in the last several years it has been steadily replacing general purpose programming languages in all the engineering disciplines.

12. Electrical Engineering
These images simulate the visual system used in a housefly brain to detect collisions. The techniques developed are being used in autonomous robot systems that depend upon vision for navigation. The data was processed using MATLAB.
For example, a project currently underway at the University of Utah Department of Electrical Engineering is using information from a video camera to simulate the visual system used in a housefly brain to detect collisions. The data is processed using Matlab, then used in an autonomous robot system that depends on vision for navigation. The image on the left is the unprocessed data from the video camera – the two pictures on the right have been processed using Matlab. Potential uses for this technology include both collision warning and eventually autopilot systems for cars.

13. Biomedical Engineering
Matlab is also being used in the medical field. These images were created from MRI data, using Matlab. The actual data set is included with the standard Matlab installation, allowing you experiment with manipulating the data yourself.
These images were created from MRI scan data using MATLAB. The actual data set is included with the standard MATLAB installation, allowing you experiment with manipulating the data yourself.

14. Statics and Structures
The motion of an idealised two span bridge under the action of a moving point force across its surface, when the force velocity is equal to the first critical speed. The animation was created in matlab, using the analytical equations of motion derived in "Vibration of solids and structures under moving loads" Fryba, L, 1999

15. Dynamics
Click and watch

16. Robotics Click and watch
In this Cartesian Motion we have fixed the TCP (Tool Center Point) in space at pos=(430,0,750). This simulation was made with Matlab R12.
Click and watch

17. Fluid Dynamics
Computational fluid dynamics is an area that is especially well suited to formulating problems as matrices. This particular image is the result of a finite element analysis. A gas generator, in the lower left corner of the model creates high temperature and pressure gas, which travels thru a curved pipe shown near the center of the model, and into a “plenum” – which is just a fancy word for a gas holding tank. The arrows represent both the direction in which the gas is traveling, and the velocity of the gas. This is actually a three dimensional image, which could be rotated in Matlab and viewed from any angle.
Results from a finite element analysis code were post processed using MATLAB to create this image.

18. 3D Plotting and Volume Visualization
A 3-D isosurface plot revealing the geodesic dome structure of a carbon-60 or “fullerene” molecule (molecules composed entirely of carbon).

19. Widely used in Academia
eg. University of Colorado:

20. MET?!

21. Working with Matlab
We’ll start learning the details of how to use MATLAB now:
In Windows or Apple operating systems click on the desktop icon
In Unix type: MATLAB at the shell prompt.
MATLAB opens to a default window configuration:
Of course, at this point we haven’t learned how to use Matlab, however you can see from the following demonstration just how easy it is to use the command window.

22. MATLAB uses a standard windows menu bar

23. There are 7 windows. Lets see what they are.
MATLAB Windows
MATLAB uses several different windows to display data, commands and results.
There are 7 windows. Lets see what they are.
Here you see the Matlab desktop. In the command window we first define a variable called E that represents the amount of energy used in one day. Notice that Matlab uses a syntax similar to that used on your calculator for scientific notation. Now we need to change the value of E to J/day, by multiplying by the appropriate conversion factors – 3600 for seconds to hours and 24 for hours to days Next we define a variable c to represent the speed of light. Finally we can combine these variables and solve for the mass. As you can see, we calculate that mass is equal to 3.7 times 10 to the 14th kg.

24. 1- Command Window 4- Current Directory 2- Command History
Enter commands at the prompt
4- Current Directory
2- Command History
3- Workspace Window

25. You can use the command window much like you’d use a calculator
Enter commands at the prompt
You can use the command window much like you’d use a calculator
The standard order of operation rules apply

26. 1- Command Window 1- Command Window Enter commands at the prompt
Similar to a scratch pad
Once you hit enter, you can’t edit any commands
You can retype them or use the arrow keys to retrieve commands and edit them before hitting enter again

27. 2- Command History 2- Command History
You can transfer commands from the command history to the command window
Double click on a command
Click and drag

28. 2- Command History 2- Command History
Records the commands you issue in the command window
When you exit the command window, or when you issue the clc command, the command window is cleared
But the command history remains

29. 3- Workspace Window 3-Workspace Window
Variables that you introduce are written here.

30. Scalar Vector 2-D Matrix
Keeps track of the variables you’ve defined (Name, Value, Size, Bytes, Class)
You may need to click on the name bar and select size and bytes in order to see these parameters

31. 4- Current Directory window

32. 4- Current Directory Window
The current directory window is a list of files.
When you try to load information from a file or try to save information – MATLAB uses the current directory.

33. 5- Document Window
If you double click on any variable in the workspace window MATLAB launches a document window containing the array editor.
You can edit variables in the array editor.

34. 5- Document Window

35. 6- Figure Window When Figures are created a new window opens.
It’s extremely easy to create graphs in MATLAB.

36. Plotting x versus y.

37. 6- Figure Window

38. 7- Editing Window
This window allows you to type and save a series of commands without executing them.
There are several ways to open an editing window:
From the file menu
With the new file icon

39. Open an editing window from the file menu or with the new file icon

40. Save and Run
Write your code in the editing window, then run it using the Save and Run icon