1. ENG004 ALGORITHMS & INT. TO PROGRAMMING Week 3 “An introduction to arrays and matrices” Ahmet Anıl Dindar 07.03.2007

2. ENG004.01 2 The class facts E-mail address: iku.eng004.01@gmail.comiku.eng004.01@gmail.com Class web page: http://web.iku.edu.tr/courses/insaat/eng004/ http://web.iku.edu.tr/courses/insaat/eng004/

3. ENG004.01 3 Last week What is Algorithm and Programming? Why do we need programs? A powerful tool- MATLAB What is MATLAB? Why MATLAB? How to use it? The first commands in MATLAB.

4. ENG004.01 4 This week Variables  Defining a new variable  Assigning a value to a variable  Variable types An introduction to arrays and matrices  Entering arrays and matrices  Creating arrays and matrices manually by entering values.  Generating arrays and matrices by defining certain rules Generating arrays and matrices by defining certain rules  Creating arrays from existing arrays  By using built-in matrix generators

5. ENG004.01 5 Variables What is variable? Homer Simpson Are there anyone whose name is Homer Simpson? (probably) YES

6. ENG004.01 6 Variables: Variable is a tag given to a specific matrice, number or anything. You can change the content of the variable any time. You can name a variable with alphabetic or alpha- numeric. The variables are important in programming. A good sense and logic is essential to follow the codes.

7. ENG004.01 7 And now let’s see How it is in MATLAB! Follow me now!

8. ENG004.01 8 >> a=1 a = 1 >> a=1 a = 1 >> a+a ans = 2 Variables in MATLAB (Alphabetic): >> a=1 a = 1 >> a+a ans = 2 >> a*a ans = 1

9. ENG004.01 9 >> a1=10 a1 = 10 >> a1=10 a1 = 10 >> a1 a1 = 10 Variables in MATLAB (Alphanumeric): >> a1=10 a1 = 10 >> a1 a1 = 10 >> a1*(2*a1)/5 ans = 40

10. ENG004.01 10 >> a=10 a = 10 >> a1=5 a1 = 5 >> a+a1 ans = 15 >> a+a1*(a-a1) ans = 35 >> Variables in MATLAB:

11. ENG004.01 11 An introduction to arrays and matrices What is matrice? What is array? What are the matrices we use? What are the calculations? The properties of the matrices? The matrices named with variables?

12. ENG004.01 12 Creating a Matrice >> a=[1 3 4] a = 1 3 4 >> a1 = 1 2 3 Row Matrix (Vector) Column Matrix (Vector)

13. ENG004.01 13 Creating a Matrice >> ali=[1 2 3;4 5 6;7 8 9] ali = 1 2 3 4 5 6 7 8 9 An Ordinary Matrice

14. ENG004.01 14 Generating arrays and matrices by defining certain rules: >> a=(1:10) a = Columns 1 through 7 1 2 3 4 5 6 7 Columns 8 through 10 8 9 10 Generic Creation (one by one): >> deli=(1:2:10) deli = 1 3 5 7 9 >> Generic Creation (two by two): >> deli=(10:-2:0) deli = 10 8 6 4 2 0 Generic Creation (???):

15. ENG004.01 15 Generating arrays and matrices by defining certain rules: >> ones(1,10) ans = 1 1 1 1 1 1 1 1 1 1 >> zeros(1,5) ans = 0 0 0 0 0 Some Special Matrices What about a matrice with full of 2’s >> twos(1,5)

16. ENG004.01 16 Generating arrays and matrices by defining certain rules: >> ones(1,10) ans = 1 1 1 1 1 1 1 1 1 1 >> zeros(1,5) ans = 0 0 0 0 0 Some Special Matrices What about a matrice with full of 2’s >> twos(1,5)

17. ENG004.01 17 Creating matrices from matrices >> a=(1:5) a = 1 2 3 4 5 >> b=(2:6) b = 2 3 4 5 6 >> c=[a;b] c = 1 2 3 4 5 2 3 4 5 6 Using matrices to create new matrices

18. ENG004.01 18 Assignment There is not any assignment!

19. ENG004.01 19 Next week... WeeksDateClassAssignment 121.02Introduction to the classRegistration 228.02Exploring MATLABAssignment 1 307.03 Arrays and Matrix Operations N.A. 414.03 Arrays and Matrix Operations Assignment 2 521.03 Arrays and Matrix OperationsAssignment 3 628.03Polynomials and curve-fitting Assignment 4 704.04Descriptive statistics Assignment 5 811.04Programming Elements of MATLAB N.A. 918.04Programming Elements of MATLAB Assignment 6 1025.04Programming Elements of MATLAB Assignment 7 1102.05Plotting and Animations N.A. 1209.05Plotting and Animations Assignment 8 1316.05Numerical Integration Assignment 9 1423.05Symbolic Math Assignment 10 1530.05Take-home final projectN.A.

20. ENG004.01 20 See you next week!

21. ENG004.01 21