Intro. to MATLAB

By Hisham Abuella

TA & RA in ECE @ Istanbul ehir University

Email : hishamabuella@std.sehir.edu.tr

Outline

Where to use MATLAB ?

What is Matlab ?

MATLAB Desktop

Exercise 1

Matrices & Vectors

Exercise 2

Useful Sites

Where to use MATLAB ?

Dealing with Matrices and Arrays

2-D and 3-D Plotting and graphics

Linear Algebra

Algebraic Equations

Statistics

Data Analysis

Calculus and Differential Equations

Numerical Calculations

Integration

Transforms

Curve Fitting

What is Matlab ?

Stands for MATrix LABoratory

Interpreted language (Line by Line)

Scientific programming environment ( cos , sin , ....)

Very good tool for the manipulation of matrices ( rank , inv ....)

Great visualisation capabilities ( plot , stem ....)

Loads of built-in functions ( Use help you will be surprised...)

Easy to learn and simple to use ( Use help of matlab + lot of online examples ....)

MATLAB Desktop

1- Command Window

2- Command History

3- Workspace

4- Current Directory

How you will work on matlab this session ?

1- Is the matlab installed on your computer ?

search for matlab ...

2- Use

http://www.tutorialspoint.com/matlab/try_matlab.php

01 The MATLAB desktop

https://youtu.be/PfklSSxZSZU?t=43s

Exercise 1

Hint :^ : powersqrt: square root23 = (2^3)

Solutions to Exercise 1

https://youtu.be/rZuAns0iEt4?t=20s

Matrices & Vectors - I

Nearly every thing in MATLAB is in matrices

Easy to define: >> A = [16 3; 5 10]

A = 16 3

5 10

Use , or to separate row elements

use ; to separate rowsTry the same line without the semicolon and comments

Access elements of a matrix

>>A(1,2)

ans=

3

Remember Matrix(row,column)

Matrices & Vectors - II

Vectors - special case - n = 1 column vector- m = 1 row vector

The : operator

VERY important operator in Matlab

Means to

>> 1:10

ans =

1 2 3 4 5 6 7 8 9 10

The : operator and matrices

For Matrix

>>A(3,2:3)

ans =

1 7

>>A(:,2)

ans =

2

1

1

Whatll happen if you type A(:,:) ?

Creating Vectors

1- Create vector with equally spaced intervals

x=0:0.5:pi

2- Create vector with n equally spaced intervals

x=linspace(0, pi, 7)

Note: MATLAB uses pi to represent , uses i or j to represent imaginary unit

Creating Matrices

zeros(m, n): matrix with all zeros

ones(m, n): matrix with all ones.

eye(m, n): the identity matrix

randn(m, n): normally distributed random

Operations can be done : +: addition

-: subtraction

^: exponentiation

*: multiplication

/: division

Manipulating Vectors

Evaluated element by element.' : array transpose (non-conjugated transpose)

.^ : array power

.* : array multiplication

./ : array division

Manipulating Matrices

Try These :

>> A ' % transpose -For : &

>> B*A % matrix multiplication

>> B.*A % element by element multiplication

>> A\B % left division same as INV(A)*B

>> B/A % matrix division

>> B./A % element by element division

>> [B A] % Join matrices (horizontally)

>> [B; A] % Join matrices (vertically)

>> A-B % Subtract B from A

>> A^2 % calculate A square

B =

-1 3 1

4 6 8

2 0 2

A =

4 2 1

5 4 -1

2 0 7

Some Built-in functions

mean(A):mean value of a vector

max(A), min (A): maximum and minimum.

sum(A): summation.

sort(A): sorted vector

median(A): median value

det(A) : determinant of a square matrix

Inv(A): Inverse of a matrix A

Exercise 2

Exercise 2 (Continue)

Hint : use A\B

Solutions

https://youtu.be/pTdkD1UpGjU?t=28s

HW

Useful Sites

http://www.see.ed.ac.uk/teaching/courses/matlab/

http://www.tutorialspoint.com/matlab/matlab_overview.htm

http://www.mathworks.com/help/matlab/index.html

http://www.mathworks.co.uk/matlabcentral/

Next session ...

Plots in Matlab Try: stem , plot ......

Relational & Logical Operators Try: && > == ||.....

If-Else Statement

For Loops

While Loops

Functions and Scripts