Introduction to Matlab

1
Introduction to Matlab

• 2E1215, Lecture 1

2
Overview

• The Course 2E1215
• Course contents and literature
• Course Guide
• Matlab Demo
• Background to Matlab
• Interactive Calculations
• Vectors and Matrices
• Graphical Illustrations

3
Course Objectives

• Student Handbook
• 1 credit self study course
• Eligible for E and D
• Objectives
• To gain basic knowledge of the Matlab programming
  language
• To prepare for other courses where Matlab is used
• To give insight into a state of the art tool in
  technical computation and visualization

4
Matlab at KTH

• 2D1240 Numeriska metoder
• 5B1209 Signaler och system I
• 2E1313 Signaler och system II
• 2E1315 Signaler och system II, D
• 2E1280 Modellering av industriella processer
• 12E1200 Reglerteknik ak, F,M,T
• 2E1211 Reglerteknik ak, E
• 21252 E Reglerteknik fk
• 2E1262 Olinjär reglering
• 2E1291 Kemiteknisk processreglering
• 2E1241 Projektkurs i reglerteknik
• 2E1421 Signalteori
• 2E1340 Digital signalbehandling
• 2E1350 Adaptiv signalbehanling
• 2E1366 Projektkurs i signalbehandling och digital
  kommunikation
• 2E1431 Kommunikationsteori
• 2E1435 Kommeunikationsteori fk

• etc...

5
Prerequisites

• Basic knowledge from calculus and linear algebra
• Basic programming experience (helpful, not
  necessary)
• Internet and computer experience
• Curiosity!

6
Course Literature

• An Introductory Matlab Course - with Engineering
  Applications
• by Niclas Bergman and Fredrik Gustafsson.
• The course includes Part 1.
• Available at STEX (Osquldas v 10)
• Teaches practical Matlab usage (not a full
  manual)
• Basic description of theoretical concepts
• Based on examples with guided tours of the system
• Exercises with solutions
• Suggested exercises 1-5, 8-17, 21, 23-32, 34, 37,
  40-41, 44, 47-48
• Applications from engineering courses

7
Course Guide
control.s3.kth.se

• Registration
• Examination
• Schedule
• Information

8
Course Guide - Registration

• control.s3.kth.se

Internet
InternetServer
9
Course Guide - Registration

• Registration is mandatory
• At the course webpage
• This registration sent to DEF

10
Course Guide - Studies

• Self studies, guided tours
• Solve exercises in four computer sessions
• Questions via E-mail
• Examination by mail

?
11
Self studies - availability

• The KTH CD-rom
• Matlab is installed in most computer labs
• On Linux machines at Elektro type

module add matlab matlab
12
Computer Exercises

• D-students need account at Elektro
• Course registration necessary.
• Deadline Thursday 14/3
• If you havent, choose user name at KTH
• https//www.kth.se/student/login
• Visit Elhand, Osquldas v 10, floor 2
• 18/3 --- bring identity card

13
Course Guide - Marks within 24h

020216 2156
Internet
LADOK Report
020301
14
Matlab Background

• MATLAB MATrix LABoratory
• Originally a user interface for standard
  routines in numerical linear algebra
  (Lapak/Linpak) designed by Cleve Moler
• Commercialized 1984 by Mathworks (3 pers)

15
Matlab Background

• Swedish agent COMSOLCOMputer SOLutions Europe.
• An alternative to MATLAB is MATRIX-X
• Mathematica and Maple are complements
• Octave is a free (GNU) alternative

16
Construction

• The core functionality in MATLAB contains
  compiled C-routines
• Most of the functionality is given as m-files,
  categorized in toolboxes
• Dynamical simulation is performed in Simulink

Contr. Syst.
Sig. Proc
Simulink
m-files
C-kernel
17
Construction

• Standard MATLAB contains thousands of m-files,
  source code that can be copied and altered
• MATLAB is available for PC (Windows/Linux), Mac
  and Unix (Sun/HP/VMS/SGI/Alpha/...)
• MATLABs m-files are platform independent
• The latest version is called MATLAB 6.2, Release
  13 (2002).
• Before that, we had Release 12.1, Matlab 6.1
  (2001), Release 12, Matlab 6.0 (2000) and
  Release 11, Matlab 5.3 (1999)

18
Interactive Calculations

• Matlab is interactive and you do not have to
  declare variables
• gtgt 234/2
• gtgt a5e-3 b1 ab
• Most elementary functions and constants are
  already defined
• gtgt cos(pi)
• gtgt abs(1i)
• gtgt sin(pi)
• Last call gives answer 1.2246e-016 !?

19
Floating point numbers in Matlab

• IEEE Standard for double precision
• x (1f )2e
• f d1/2 d52/252, dk 0,1
• -1022 lt e lt 1023
• Round-off eps 2-52
• Underflow realmin 2-1022
• Overflow realmax (2-eps) 21023

20
Interactive Calculations

• Matlab uses double precision which gives
  approximately 16 significant figures
• gtgt format long
• gtgt format compact
• Variables can be stored on file
• gtgt save dump
• gtgt clear
• gtgt load dump

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Interactive Calculations

• All variables are shown with
• gtgt who
• gtgt whos
• Rapid help with syntax and function definition
• gtgt help function
• An advanced hyperlinked help system is launched
  by
• gtgt helpdesk
• All manuals are provided in PDF-format

22
Vectors and Matrices

• Vectors (arrays) are defined as
• gtgt v 1 2,4,-5
• All common operators are overloaded
• gtgt v 2
• Visualization of vector data is available
• gtgt plot(v)
• gtgt plot(v,)
• gtgt bar(v)
• gtgt pie(abs(v))

23
Vectors and Matrices

• Matrices (2D-array) are defined similarly
• gtgt A 1 2 34,-5,65 -6,7
• Common operators are available
• gtgt B A
• gtgt AB
• gtgt AB
• MATLAB is case-sensitive A and a are two
  different variables

24
Vectors and Matrices

• Indexing using parentheses
• gtgt A(2,3)
• Indexing of a complete row/column is performed by
  the colon-operator
• gtgt A(12,)
• For instance, 12 is the same as 1 2,
• 238 is the same as 2 5 8
• Arbitrary indexing is allowed using vectors
  between 1 and the matrix dimension
• gtgt A(3 2,2 1)
• gtgt A(3,2) A(3,1)A(2,2) A(2,1)

25
Vectors and Matrices

• Elementary functions are also overloaded
• gtgt sin(A)
• gtgt help elmat help elfun
• Specialized matrix functions and operators
• gtgt sqrtm(A)
• gtgt A.2
• gtgt A2
• gtgt A.B

26
Vectors and Matrices

• Numerical linear algebra
• gtgt inv(A)
• gtgt B\A
• gtgt det(A)
• gtgt rank(A)
• The number of input and output arguments can
  often be varied
• gtgt V,Deig(A)

27
Graphical illustrations

• Three-dimensional graphics
• gtgt A zeros(32)
• gtgt A(1416,1416) ones(3)
• gtgt Fabs(fft2(A))
• gtgt mesh(F)
• gtgt rotate3d on
• Many visualization attributes can be changed from
  the figure menu (from version 5.3 and higher).

28
Graphical illustrations

• Bitmap images can also be visualized
• gtgt surfl(F)
• gtgt load mandrill
• gtgt image(X) colormap(map)
• gtgt axis image off
• Example of lighting and camera settings
• gtgt knot
• gtgt cameramenu
• gtgt material metal

29
Next Lecture

• Programming in MATLAB