MATLAB stands for MATrix LABoratory.

1
Introduction

• MATLAB stands for MATrix LABoratory.
• Basics
• Matrix Manipulations
• MATLAB Programming
• Graphics
• Image types
• Image Processing
• Useful functions

2
Basics

• Basic data element is an array that does not
  require dimensioning.
• A1 2 34 5 6 7 8 9
• A 1 2 3
• 4 5 6
• 7 8 9

3
Matrix Manipulations

• Sum(A) sums of the columns of A
• A Transpose of A
• Diag(A) gives diagonal elements of A
• Min(A) minimum element column wise of A.
• Max(A) maximum element column wise of A.
• Mean(A) Average element column wise of A.
• Std(A) Standard deviation column wise of A.
• X zeros(5,5) Y ones(6,6)
• Mrand(5,5) N randn(6,6)
• A150
• A0pi/4pi0 0.7854 1.5708 2.3562 3.1416

4
Matrix Manipulations (contd..)

• B magic(4) 16 2 3 13
• Dürer's magic square 5 11 10 8
• 9 7 6 12
• 4 14 15 1
• All numbers are stored internally using the long
  format specified by the IEEE floating-point
  standard.
• Floating-point numbers have
• finite precision ?16 significant decimal digits
  and
• finite range ? 10-308 to 10308.

5
Matrix Manipulations (contd..)

• A(,2) ? deletes 2nd column.
• A(2212) results in row vector of remaining
  elements.
• A A.5 ? Element-by-element multiplication.
• indices find(isprime(A))
• format ? this command can be used for formatting
  the displayed numeric output (either in short or
  long format).

6
MATLAB Programming

• MATLAB has several flow control constructs
• if statements
• switch statements
• for loops
• while loops
• continue statements
• break statements

7
Graphics

• Plotting sinusoidal function using the plot
  function.
• Cylinder ? unit cylinder with default 20 points
  on the circumference.
• Sphere ? unit sphere with default 20 points on
  the circumference.
• Subplot(m,n,p) ? partitions the figure window
  into m-by-n matrix of small subplots and selects
  the pth subplot for the current plot.

8
Graphics (contd..)

• mesh ? produces wire frame surfaces that color
  only the lines connecting the defining points.
• surf ? displays both the connecting lines and the
  faces of the surface in color.
• Light and camera effect on the visualization of
  2-dim sinc function (i.e. sin(r)/r) between x and
  y directions.

9
Types of Images

• Index images
• Intensity images
• Binary images
• RGB images

10
Image Processing

• Dürer's magic square
• Animation using EraseMode property.
• Animation using Movie method
• Functions
• Imread ? read an image
• Imwrite ? writes specified matrix into an image.
• Image ? displays specified matrix as an image.
• Imshow ? Displays an intensity (gray level)
  image.
• Im2frame ? converts an image into movie frame.
• Avifile ? creates an avifile object.
• Addframe ? adds movie frame to avifile object.
• Getframe ? returns movie frame.
• Movie ? Play recorded movie frames.
• close ? closes current figure.

11
Useful functions

• help fnName ? help on any function.
• whos ? information on current variables in the
  workspace.
• guide ? GUI editor.
• demo ? Matlab toolboxes and functions demo.
• eval(str) ? evaluates expression in the str
  variable.
• load abc.mat ? loads data in the matlab file.