Exam 3: Review (part 1)

1. Exam 3: Review (part 1)

2. Test 1 - Outcomes • Computers & Solutions • Understand the basic concepts of a computer: the hardware, the software, the different languages. • List and follow the steps to solving a problem • Apply problem solving approach • Identify different strategies to frame problems • Variables & Data Types • Identify the different windows in MATLAB • Create and assign values to variables in MATLAB • Utilize variables for basic calculations

3. Test 1 - Outcomes • Inputs & Outputs • Give the user the ability to enter words • Show results to the screen:  • for the purpose of debugging (i.e. finding errors in the code) • to show values only • to format a sentence that shows result • Operators & Conditionals • Understand 0 and 1. False and True • Write conditional statements using appropriate operator syntax • Know and apply the syntax of an ifand switch statement: • what keywords are mandatory • what keywords are optional • what order do the keywords go in?

4. Review Questions CPU stands for _______________________. • Counter productive units • Central processing unit • Copper Part Unit • None of the answers are valid

5. Review Questions • A TYPICAL keyboard is considered to be: • Input device • Output device • Input/output device • None of the above www.wikipedia.com

6. Review Questions Which command creates a variable named age, assigns the value 29, and suppresses the output? • Age = 29 • age =29 • 29 = age; • None of the options are valid

7. Review Questions Which of the following is NOT a valid variable name? • $_money • 2TypesOfRockets • Input • i • j • Name 1

8. Review Questions Which of the following are Boolean Operators? How about relational operators? • +-*/ • <= >= < > == ~= • || && ~ • None of the above are valid

9. Review Questions Will the following script file allow the user to enter her/his name properly? clc clear name = input(‘Enter your name’); fprintf(‘Welcome %s!\n’, name); • Yes • No

10. Review Questions Will the following script file allow the user to enter her/his name properly? clc clear name =input(‘Enter your name’,’s’); fprintf(‘Welcome %s!\n’,name); • Yes • No

11. Review Questions • What will appear in the command window after executing this code: z=5; fprintf('The answer is z') • The answer is 5 • The answer is z • The answer is 5.00 • Will return an error.

12. Review Questions • What are some methods to display results? • Which method allows to print results with a specific format? • What are the 4 common placeholders? • What is the purpose of placeholders? • Which function actually uses placeholders? • What are format modifiers? • Which placeholder can have a format modifier that controls the number of decimal places? • If there are 3 placeholders in the control string, how many variables can be printed to the screen?

13. Review Questions • What are the two conditionals shown that allow to skip code? • Regardless whether it is if or switch, which keyword is always associated with both? • What other keywords are associated with if? • What other keywords are associated with switch?

14. Review Questions Why does the following script result in an error? clc clear X = input(‘Enter a value: ’); if X = 2 disp(‘2’) else disp(‘error’) end

15. Review Questions • Is each statement valid? Which will create a string? • x = “EGR 115” □ Valid □ Invalid □ String □ Not a string • x = ‘EGR 115’ □ Valid □ Invalid □ String □ Not a string • x = sprintf(‘ %s %d’,class_name,class_num) □ Valid □ Invalid □ String □ Not a string • x = str2num(‘115’) □ Valid □ Invalid □ String □ Not a string • x=num2str(‘115’) □ Valid □ Invalid □ String □ Not a string • X=double(‘EGR’) □ Valid □ Invalid □ String □ Not a string

16. Test 2 - Outcomes • Library Functions • Recognize function vocabulary words • variable collections, function call, arguments • Understand how a function works overall • Know and apply the functions that can round up/down/w.r.t 0.5 • Generate a random value between two specific limits • Know the syntax of and purposes of the mod() function • Loops • Recognize when a loop is useful • Write and apply the syntax of a for loop and a whileloop appropriately • Develop an algorithm to solve a problem using a for and whileloops • Understand and apply running totals

17. Test 2 - Outcomes • Numerical Methods • Know when numerical methods are used • What loops are used and how • Arrays • Recognize when an array is useful • Create scalars, vectors, matrices, transpose • Use functions on arrays  • Augment, concatenate, and diminute arrays

18. Review Questions • What are the possible outcomes of the following code Rand_num= round((rand*4)+6) • 6,7,8,9 • 7,8,9,10 • 7,8,9 • 6,7,8,9,10 • None of these

19. Review Questions Which loop form is best for this client’s demand: “Add up all of the values the user provides, stopping when they’ve entered the known number of values” • for • while • if • None of these answers are valid

20. Review Questions • What is the running total? sum=0; for k=1:5 sum=sum+k*2; end • What is the running total? sum=0; for k=1:5 sum=k+k; end

21. Review Questions • MATCH: • ( ) 1. Access content of a cell in a cell-array • [ ] 2. array referencing • { } 3. creating normal arrays, and concatenating

22. Review Questions • What is a vector( row vector or column vector)? • How to create a vector? • What is a matrix ? • How to create a matrix? • How to refer/replace the element(s) in a vector/matrix? • How to define new columns? • How to define new rows?

23. Review Questions [ ] Given 1 5 6 dataM= 8 9 0 4 3 2 • How do we access/reference element 0? • How do we extract vector ? • How do extract vector • How do we extract matrix ? • How do we extract matrix ?

24. Review Questions • Will the following operations work? What is the size of the final result? [1 2 3].*[2 3 4] [1 2 3]*[3 4 5] [1 2 3]*[1;2;3] [1 2;3 4; 5 6]*[5 6; 7 8; 9 0] [1 2;3 4; 5 6]*[1 2 3;3 4 5] [1 2;3 4; 5 6].*[5 6; 7 8; 9 0]

25. Test 3 - Outcomes • File I/O • Utilize and apply files appropriately • Know when and how to use dlmread()or xlsread() • Apply logical operations on arrays • Dialog Boxes • Select and apply the appropriate dialog box • Know how to format dialog boxes • Know what data type is returned by a dialog box input • Strings • Know how to harcodestrings • Know how to prompt the user for strings • Recognize and apply functions used specifically for strings • Know how to compare strings together • Augment, concatenate, diminute strings

26. Test 3 - Outcomes • Functions • Recognize when and how to apply functions • Know the syntax of creating and calling functions • Understand the unique way that data flows in and out of a function • Create and call functions with multiple inputs and return values • Know how to ignore return values • Plotting • Create arrays to plot data • Know and apply functions to plot data • Low Level Files • Recognize when to use low-level functions • Know and apply the commands needed to open, read, write, append, and close a file

27. Review Questions • Consider the following MATLAB code, and decide which type of data you are collecting R = xlsread('myFile.xlsx'); • numerical • strings • Cell array • Choice a & c are correct.

28. Review Questions • Assume the file is the following: • What will be the result of this command: >> [x1, x2] = xlsread(‘data.xlsx’) B? A?

29. Review Questions • inputdlg() accepts its input arguments as ____________ and return a __________ of ___________. • msgbox() accepts _____________ as its input arguments (data type) (data type) (data type) (data type)

30. Review Questions • What value will be in the variable len after executing this MATLAB code? • 10 • 11 • 12 • 13

31. Review Questions • After running this MATLAB code, what value will be saved in the variable str_edit • Hello Wo • lo W • lo Wo • loWo

32. Review Questions • After running this MATLAB code, what value will be saved in the variable str • Hello World • HelloWorld • [ ] • Will return an error message

33. Review Questions • After running this MATLAB code, what values will be saved in the variable str1 and str2 • str1: ‘Hello ’, str2: ‘ World’ • str1: ‘Hello’, str2: ‘World’ • str1: ‘Gdkkn’, str2: ‘Vnpkc’ • None of these

34. Review Questions • What is the value stored in the variable chkchk=strcmp(‘yes’,’Yes’) • 0 • 1 • [0 1 1] • [1 1 1] • It cannot be determided

35. Review Questions • What is the value stored in the variable chkchk=strcmpi(‘yes’,’Yes’) • 0 • 1 • [0 1 1] • [1 1 1]

36. Review Questions • What is the value stored in the variable chkchk=strcmp(password,‘hd93yf8’) • 0 • 1 • [0 1 1] • [1 1 1] • It cannot be determined

37. Review Questions • What is the value stored in the variable chk chk= (‘Mark’ == ‘mark’) • 0 • 1 • [1 1 1 1] • [0 1 1 1]

38. Review Questions • The part that is circled is called: function W = M (A,B) • function • Return variables • Function name • Parameters

39. Review Questions • The part that is circled is called: function W = M (A,B) • function • Return variables • Function name • Parameters

40. Review Questions • The part that is circled is called: W = MyFun (A,B) • Function call • Return values • Arguments • Parameters

41. Review Questions • The arguments’ names in the function call MUST match the parameters’ name in the function header? • In the function header, how many parameter can the function have? How many return values can the function have? • Does the number of return values in the function header need to match the number of the collection values in the function call?

42. Review Questions • Consider the following MATLAB code, and decide where is the error: • The error is in the FIRST line. • The error is in the SECOND line. • The error is in the THIRD line. • The error is in the FOURTH line.

43. Review Questions • polyfit() will return the coefficient of the polynomial that best fits the data given. • TRUE • FALSE

44. Review Questions • Which of the following built-in function, will CREATE a plot. • polyval() • polyfit() • xlabel() • polar()

45. Review Questions In the following syntax, __C__= fopen(___A_____, _ B__) • MATCH: _____ The permission string _____ The file’s actual name _____ The file identifier (i.e. cursor position)

46. Review Questions • When using the ‘r’ access-mode (i.e. permission), the initial position of the pointer (i.e. cursor) will be: • At the beginning of the file • At the end of the file • At halfway into the file • It will stay where it is (no change from last time the file was open)

47. Review Questions • Assuming that we are reading a text file that includes only one line and we saved it to a variable named str. • Look at the screenshot below. Can you tell which function was used to read such file: • fgetl() • fgets() • fget() • None of the above

48. Review Questions • Assuming that we are reading a text file that includes only one line and we saved it to a variable named str. • Look at the screenshot below. Can you tell which function was used to read such file? • fgetl() • fgets() • fget() • None of the above

49. Review Questions • Consider the code written below, then answer the following questions: • If a file exists with the same name will it be deleted? • If the files doesn’t exist, will it be created?

50. Review Questions The file contains the retired hurricane names, and the year they were retired: Assume the data has been properly uploaded using textscan() and extracted into Col1, and Col2. Which command(s) would find the year a specific name has been retired? For example: NameUserChose = ‘Lili’; • if Col1 == NameUserChose • disp(Col2) • end • B. Year = Col2(strcmp(Col1,NameUserChose)); Row = find(strcmp(Col1,NameUserChose)); year = Col2(Row);