An Introduction to MATLAB Lesson 1

1
An Introduction to MATLABLesson 1

• Dr. Samir Al-Amer
• Term 061

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MATLAB

• MATLABMATrix LABratory
• It is widely used to solve different types of
  scientific problems.
• The basic data structure is a complex double
  precision matrix.

3
Run MATLAB

• From Start Menu
• Select Programs
• Select MATLAB

MATLAB Prompt Tells that MATLAB is ready for
your command
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MATLAB Layout

• 1 to 5 different windows can be selected to
  appear (View)

Current directory window
Command History window
Command window
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MATLAB shortcuts
Help
SIMULINK
Open files
New file
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MATLAB AS A CALCULATOR
Command window
gtgt 394.45 ans 176.6000
Command window
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MATLAB

• Variable names
• Starts with a letter
• Up to 31 characters ( some use 19 or 21)
• May contain letters, digits and underscore_
• Case sensitive (A is not the same as a)

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MATLAB Assignment

• Variable names
• Starts with a letter
• Up to 31 characters ( some use 19 or 21)
• May contain letters, digits and underscore_
• Case sensitive (A is not the same as a)

• A2.3
• A
• 2.3000

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Scalar Assignment
The square braces are used to define
matrices. We can use them for scalars too.

• A2.3
• A
• 2.3000

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Row vector
X2,3 7
X 2 3 7
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Column vector
X23 7
X 2 3 7
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MATLAB Statements
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MATLAB Statements
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Polynomials
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Help

• A good idea is use the help
• help provides information about the available
  functions and how to use them.
• Try
• help eig
• help inv
• help roots

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Programming in MATLAB

• There are two types of MATLAB programs

script files
function files
script file P1 3 2 roots(P)
function yfun(x) yx23x22
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Programming in MATLABScript files

• A Script file contains a set of MATLAB command
• Use them when you have a long sequence of
  statements to solve a problem
• Can run the program by typing its name in the
  command window or from tools in the editor
  window.

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Logical Operators
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Logical Operators
if (Xgt6) (xlt3)
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If structures

• General form
• If condition
• statements
• else
• statements
• end

If (xgt0) sign1 elseif (x0)
sign0 else sign-1 end
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for loops

• General form
• for indexinitial increment limit
• statements
• end

s0 for i1311 ssi end
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Example

• MATLAB program to find the roots of

Result
X 1.1111 X 1.0483 X 1.0472 X
1.0472
program 1 performs four iterations of
Newtons Method X.7 for i14 XX
(2cos(X)-1)/(-2sin(X)) end