CPET 190

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CPET 190

• Lecture 3
• Problem Solving with MATLAB
• http//www.etcs.ipfw.edu/lin

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Lecture 3 MATLAB Development Environment

• 3-1 Desktop Tools
• Starting and Quitting MATLAB
• Command Window
• Running Functions
• Entering Variables
• Controlling Input/Output
• Searching Items
• Running Programs
• Preferences for the Command Window

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Lecture 3 MATLAB Development Environment
(continue)

• 3-1 Desktop Tools (continue)
• Command History
• The MATLAB Workspace
• Help Browser
• Workspace Browser
• Current Directory Browser
• Edit/Debug

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Lecture 3 MATLAB Development Environment
(continue)

• 3-2 Useful Commands
• The MATLAB Search Path
• Number Display Formats
• Session Log
• MATLAB Managing Commands and Functions
• demo - Run demos
• help - Online help
• ver - Current MATLAB and toolbox versions
• version - Current MATLAB version number
• path - MATLAB Search path
• diary - Save typed commands on a named file
• Summary

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Starting and Quitting MATLAB

• Starting MATLAB
• From command window start -gt Run -gt MATLAB
• Start -gt All Programs -gt MATLAB

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Starting and Quitting MATLAB

• Quitting MATLAB
• At the MATLAB command window
• gtgt quit
• gtgt exit
• Close MATLAB Window

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Desktop Tools

• Started MATLAB and see the three sub-windows
• Command Window
• Current Directory
• Command History
• At the command
• window, we enter
• gtgthelp help

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Command Window

• Running Functions
• Entering Variables
• Controlling Input/Output
• Searching Items
• Running Programs
• Setting Preferences for the Command Window

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Running Commands

• An Example
• gtgt magic(3)
• ans
• 8 1 6
• 3 5 7
• 4 9 2

gtgt help magic MAGIC Magic square. MAGIC(N)
is an N-by-N matrix constructed from the
integers 1 through N2 with equal row,
column, and diagonal sums. Produces valid
magic squares for all N gt 0 except N 2.
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Entering Variables

• gtgt x 10
• x 10
• gtgt y 10
• y 10
• gtgt x y
• ans 100
• gtgt x / y
• ans 1
• gtgt x y
• ans 20
• gtgt x - y
• ans 0
• gtgt

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Controlling Input/Output

• Format Function control the display formats for
  numeric values
• Examples
• gtgt x 1/3
• x 0.3333
• gtgt y 1.2345e-7
• y 1.2345e-7
• gtgt format short e
• gtgt x
• x 3.3333e-001
• gtgt y
• y 1.2345e-007

Hit Enter key
MATLAB Displays
Hit Enter key
Hit Enter key
Enter x
MATLAB Displays
Enter y
MATLAB Echoes
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Controlling Input/Output (continue)

• Format Function
• gtgt help format
• FORMAT Set output format.
• All computations in MATLAB are done in double
  precision.
• FORMAT may be used to switch between different
  output
• display formats as follows
• FORMAT Default. Same as SHORT.
• FORMAT SHORT Scaled fixed point format
  with 5 digits.
• FORMAT LONG Scaled fixed point format
  with 15 digits.
• FORMAT SHORT E Floating point format with 5
  digits.
• FORMAT LONG E Floating point format with
  15 digits.

gtgt format long gtgt x x 0.33333333333333 gtgt
y y 1.234500000000000e-007
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Controlling Input/Output (continue)
gtgt format long g gtgt x x 0.333333333333333 gt
gt y y 1.2345e-007 gtgt format
bank gtgt x x 0.33 gtgt y y 0.00 gtgt format
rat gtgt x x 1/3 gtgt y y 1/8100446

• Format Function
• gtgt help format
• FORMAT SHORT G Best of fixed or floating point
  format with 5 digits.
• FORMAT LONG G Best of fixed or floating
  point format with 15 digits.
• FORMAT HEX Hexadecimal format.
• FORMAT The symbols , - and blank
  are printed for positive, negative and zero
  elements. Imaginary parts are ignored.
• FORMAT BANK Fixed format for dollars and
  cents.
• FORMAT RAT Approximation by ratio of
  small integers.

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Controlling Input/Output (continue)

• File -gt Preferences
• Allows you to set up various numeric display
  formats through GUI

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Suppress Output

• Suppressing Output
• End of the statement with a semicolon
• Increase statement and program execution speed
• An Example
• gtgt x 10
• gtgt y 10
• gtgt product x y
• Product 100

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Entering long Statements

• If a statement does not fit on a line (too long),
  uses an ellipsis (three periods), follow by Enter
  or Return, to indicate the continuation of the
  statement to the next line
• For an example
• gtgt x 1 2 3 5 6 7 ...
• 8 9 10
• x
• 51

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Command Line Editing and Command History

• Command Line Editing
• Keys such as right arrow ?, down arrow ?, up
  arrow ?, left arrow ?, etc, can be used to edit
  commands
• Command History
• The entered commands at the Command Windows are
  recorded or logged in the Command History
• We can view previous commands or statements
• We can copy or execute rerun previous statements

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The MATLAB Workspace

• who function
• whos function
• clear function

gtgt who Your variables are x y gtgt whos Name
Size Bytes Class x 1x1
8 double array y 1x1
8 double array Grand total is 2
elements using 16 bytes gtgt clear x gtgt who Your
variables are y gtgt clear gtgt whos
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The MATLAB Workspace
gtgt save 8_20_2004.mat gtgt clear gtgt whos gtgt load
8_20_2004.mat gtgt whos Name Size Bytes
Class ans 1x1 8 double array
x 1x1 8 double array y
1x1 8 double array Grand total
is 3 elements using 24 bytes gtgt clear gtgt whos

• save function
• load function

Current Directory
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Save Command

• We can use help save to see documentation of
  SAVE function and learn how to Save workspace
  variables to disk.
• SAVE FILENAME saves all workspace variables to
  the binary "MAT-file, If FILENAME has no
  extension, .mat is assumed.
• SAVE, by itself, creates the binary "MAT-file"
  named 'matlab.mat'. It is an error if
  'matlab.mat' is not writable.
• SAVE FILENAME X saves only X.
• SAVE FILENAME X Y Z saves X, Y, and Z. The
  wildcard '' can be used to save only those
  variables that match a pattern.

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Save Command (continue)

• MATLAB also offers various saving options
• ASCII Options
• SAVE ... -ASCII uses 8-digit ASCII form instead
  of binary regardless of file extension.
• SAVE ... -ASCII -DOUBLE uses 16-digit ASCII
  form.
• SAVE ... -ASCII -TABS delimits with tabs.
• And more will be discussed later

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Help Browser
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Workspace Browser
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Current Directory Browser
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The Edit/Debug

• Use the Editor/Debugger to create and debug
  M-files, which are programs you write to run
  MATLAB functions.
• The Editor/Debugger provides a graphical user
  interface for basic text editing, as well as for
  M-file debugging.

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The Edit/Debug (continue)
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The Edit/Debug (continue)
Create a mlab_exs directory
Save the M-file as sine60hz.m
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The Edit/Debug (continue)
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Testing/Debugging sin60hz.m
Click -gt Debug -gt Run
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Other Commands

• Other Useful MATLAB Management Commands/Functions
  
• demo - Run demos
• help - Online help
• ver - Current MATLAB and toolbox versions
• version - Current MATLAB version number
• path - MATLAB Search path
• diary - Save typed commands on a named file

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Summary

• Desktop Tools
• Starting and Quitting MATLAB
• Command Window
• Running Functions
• Entering Variables
• Controlling Input/Output
• Searching Items
• Running Programs
• Preferences for the Command Window
• Command History
• The MATLAB Workspace
• Help Browser
• Workspace Browser
• Current Directory Browser
• Edit/Debug - a sine wave program

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Question?

• Answers
• Email lin_at_ipfw.edu