1. CS1109 L AB 3 July 3rd

2. R OAD M AP Homework submission Review How to use function and scripts While-end Finish last exercise Lab 2 Challenge questions

3. H OMEWORK SUBMISSION Zip files saving and submitting File name File location Homework 1 questions

4. L AST WEEK Logic operator == && || ~= >= <= Built in function rand fix, floor, ceil disp, fprintf

5. R EVIEW EXERCISE Compute without using Matlab (~0 & 0)||(0&0) ((~1 || 0)& (0&0))||(1&0) (~(0& 1))||(1&1) suppose a = 1, b = 3 if a>1 & b+a>2 a = 3 else a= 4 end Question: a+b = ?

6. R EVIEW EXERCISE suppose a = 1, b = 3 if a>1 & b+a>2 a = 3; elseif a> -1 a= 4; else a = 5; end Question: a+b = ?

7. R EVIEW EXERCISE suppose a = 1, b = 3 if a>-1 & b+a>2 a = 3; elseif a> -1 a= 4; else a = 5; end Question: a+b = ?

8. D OUBLE INEQUALITY Type in MATLAB z=6 4<=z<=5

9. D OUBLE INEQUALITY Type in MATLAB z=6 4<=z<=5 Something is wrong. If z = 6 then 4<=z<=5 is false. Let's figure out what went wrong later. First, design a logical statement which will give the right result. How many ways can you write it?

10. D OUBLE INEQUALITY

11. z =4 4 <=z && z<=5 4 = z

12. T HIS WEEK Scrip and Function If statement While loop For loop Array

13. H OW TO USE FUNCTION AND SCRIPTS function out_var=my function(inp_var) % Comments that explain what the function does computations out_var=desired result; End Exercise 1: Try to create a function that adds two numbers The function is called addtwo.m Input: x, y Output: z

14. function z=addtwo(x,y) % addtwo(x,y) Adds two numbers, vectors, whatever, % and output the result = x + y z=x+y; end

15. S CRIPT Scripts are the simplest kind of program file because they have no input or output arguments. Useful for automating series of commands, such as computations that you have to perform repeatedly from the command line. Exercise 2: Create a script that asks the user to input two numbers, then add the two numbers and output the sum.

17. E XERCISE 4 Create a function called new_abs.m which computes the absolute value of x Input: x Output: y (y =|x|)

19. E XERCISE 4 function y=new_abs(x) if x>=0 y=x; else y=-x; end Can you make the above code shorter?

20. W HILE while logical condition do something end While loop repeats an indefinite number of times until the logical condition matched. Exercise: Sum 1 to 100 Sum 1 to 100, only the numbers that are divisible by 3

21. C HALLENGE Q UESTIONS Write a while loop that generates random integer numbers between 1 and 5 and stops looping after it generates the same number twice. Write a while loop that generates random integer numbers between 1 and 100 and stops looping after it generates the same number twice. (Use array)