- CS1371 Computing for Engineers Test 2 Version D
October 25th, 2006
1Georgia Institute of Technology College of Computing CS 1371 Computing for Engineers Test 2 Version D - Fall Semester 2006
0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Print your WebCT username in the spaces provided, and shade the boxes of the corresponding numbers and/or letters. If your username is longer than 9 characters, shade in the boxes corresponding to the first 9.
I hereby signify that this examination paper contains my own work exclusively, and I have neither given nor received inappropriate help during the taking of this examination, in compliance with the letter and spirit of the Academic Honor Code of Georgia Tech. Name (print): Signature: TA / Section: ____________________________
Poss. Pts 20 20 20 20 20 100 Earned Pts Lost Pts
Prob. (cover) 1 2 3 4 5 TOTAL
by
Please Note: Failure to complete this front sheet correctly will cost you 5% of your grade. Please turn off (or silence) and put away any cell phones, beepers/pagers, personal radios or music players that you have in your possession
Good Luck!
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CS1371 - Computing for Engineers Test 2 Version D
October 25th, 2006
Academic misconduct (including - but not limited to - examples on the list below) could result in a zero score on this examination, an "F" final grade in the course, and/or other disciplinary action: Failure to cooperate with or follow directions given by a proctor. Failure to stop writing when the allotted time is up (as reported by a proctor). Communication with anyone other than a proctor for ANY reason in ANY language in ANY manner. Sharing of ANYTHING (e.g. pencils, erasers, paper). Writing on paper that is not given to you by a proctor. Using cell phones, beepers, personal radios or music players, etc. during the exam. Using calculators (unless explicitly permitted) or hand-held computers during the exam. Using books or other reference material during the exam. Disruption of the exam setting.
Reference Section:
diag(m) returns the diagonal elements of the matrix m factorial(n) returns n! find(m) returns the indices of the true elements of m getfield(a,att) returns the value of field att in the structure a equivalent to a.(att) image(x) - display the image from the matrix x. imread(filename) - returns a matrix representation of an image iscell(a) checks if a is of class cell (a cell array) ischar(a) checks if a is of class char (a string) isempty(here) checks if here is null (usually represented by [], the empty vector isfield(a,att) checks if att is a field in the structure a isstruct(a) checks if a is a structure length(a) largest dimension of a magic(n) builds a n * n magic square max(a) value and index of the max value in a mesh(x, y, z) plot the surface defined by the x, y and z arrays with colored lines and white faces [xx, yy] = meshgrid(x, y) compute the plaid from the x and y vectors min(a) value and index of the min value in a mod(a, b) the remainder when a is divided by b ones(rows, cols) generate a matrix filled with 1 prod(v) compute the product of all the elements in a vector v rmfield(str, att) removes a structure field setfield(str, att, value) set a structure field equivalent to str.(att) = value sin(th) sin of the angle in radians size(a) all the dimensions of a sort(v) arranges the vector v in ascending numerical order struct(att,val, ... ,att,val) builds a structure with the given attribute/value pairs sum(v) total all the elements in the vector v surf(x, y, z) plot the surface defined by the x, y and z arrays with colored faces and black lines title(str) titles the plot with the given string [x, fs] = wavread(filename) gives the waveform and sampling frequency for a .wav file (x/y/z)label(str) labels the plot axes with the given string zeros(rows, cols) generate a matrix filled with 0
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CS1371 - Computing for Engineers Test 2 Version D
October 25th, 2006
Problem 1 - Multiple Choice Questions [20 Points]
1. Which one of the following is NOT a valid structure assignment? A. myStr = struct('Phone', 'Samsung', 'Model', myStr(3).sms1 'D900')
B. = ' I hope I do well ' C. myStr[2].sms2 = 'Me too!' D. myStr(1).x = double('super')
E. None of the above, all are valid.
2. Which one of the following lines will produce an error in MATLAB? A. B. C. D. E. double('s324') + 5 'OMG' > 'g' 'donot' + 'cheat' double('Get over this!') double('stop') + [1:10]
3. Given the following matrices: A = [3 6 -1; 0 0 2; 9 0 4] B = [1 2 3; 4 5 6] C = [5 7; 0 0; -3 -1] Which of the following commands would NOT result in an error? I. [A B C] II. [A B] III. [C A] IV. [C B] A. B. C. D. E. I, II, and IV II only III only All are correct None of the above
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CS1371 - Computing for Engineers Test 2 Version D
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4. Which of the following are attributes of recursion? Circle all that apply. A. Calls a clone of itself. B. Has some kind of condition that the problem can reach every time.
C. The input must get smaller. D. All of the above.
5. If the function z = x^2 is rotated about the z-axis where x has a range of x = 0 to x = 3 and theta has a range of theta = pi to theta = pi, how far would the surface created go about the z-axis? A. B. C. D. The surface would rotate all the way about the z-axis. The surface would only rotate halfway about the z-axis. The surface would only rotate a fourth of the way about the z-axis. The surface would not be plotted because theta has negative values.
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CS1371 - Computing for Engineers Test 2 Version D
October 25th, 2006
Problem 2 Structures [20 Points]
Read the following piece of code and then answer the questions that follow.
People = struct('First', {'John', 'Mathew', 'Jessica', ... 'Chase'}, 'Last', {'Carter', 'Adamson', 'Martin', ... 'Schlumberg'},'Age', {17, 17, 18, 17}); Class = struct('First', {'John', 'Mathew', 'Jessica', ... 'Chase'},'Last', {'Carter', 'Adamson', 'Martin', ... 'Schlumberg'}, 'NumGrade', {98, 86, 73, 92}, 'Grade', ... {'A', 'B' ,'C' ,'A'}); People(1).NumGrade = Class(1).NumGrade [nu1, nu2,nu3,nu4] = Class.NumGrade setfield(People(3),'NumGrade',nu2) A = People(2).NumGrade B = getfield(People(1),'Age') C = {nu1, nu2, nu3, nu4} D = isfield(Class,'NumGrade')
A. What is the output of the following variables when the script above is executed: A B C D = = = = _____________________________________________________ _____________________________________________________ _____________________________________________________ _____________________________________________________
5 pts EXTRA CREDIT: Create a new structure array stArr which will be the same as People except without the `Age' field.
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CS1371 - Computing for Engineers Test 2 Version D
October 25th, 2006
Problem 3 Matrices [20 Points]
Read the following piece of code and then answer the questions that follow. A = [1:4; linspace(7,13,4); 15,18,21,24; 25:4:39]; B = A; C = zeros(3,3); C(1:2,1:2) = A(3:end,3:end); D = A'; B(3:end,1:2) = A(1:2,1:2); B(1:2,3:end) = A(3:end,1:2); B(3:end,3:end) = A(1:2,3:end);
A. What is the output of the following variables when the following script is executed:
A
=
_____________________________________________________
B
=
_____________________________________________________
C
=
_____________________________________________________
D
=
_____________________________________________________
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CS1371 - Computing for Engineers Test 2 Version D
October 25th, 2006
Problem 4 Recursion [20 Points]
Given the following code:
function ret = mysteryFunc(input) if input == 2 ret = 1; elseif (mod(input,2)) == 0 ret = 1 + mysteryFunc (input-1); else ret = mysteryFunc (input-1); end
1. What is the termination condition
2. What does mysteryFunc(15) return?
3. Write a function called multiplyNum that takes in 2 inputs, and returns the value of the two inputs multiplied together. The only operators allowed you are + and -. Note: - You must use recursion to receive any credit. - You may assume that the second input will be a non-negative integer Example: x = multiplyNum(5,3) Returns: x = 15
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CS1371 - Computing for Engineers Test 2 Version D
October 25th, 2006
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CS1371 - Computing for Engineers Test 2 Version D
October 25th, 2006
Problem 5 Plotting [20 Points]
P lo t 2 * s in (x x ) + x x 1 /2
4
2
Z -A x is
0
-2
-4 4 2 0 -2 Y -A x is -4 0 2 1 X -A x is 4 3 5
Write a MATLAB script to rotate the function z = 2*sin(x) + x^0.5, which goes from x = 0 to x = 5, about the x-axis, using an appropriate number of points. Be sure to include proper labels for all the axes and a title similar to the plot above. Your graph should be a smoothly colored surface with no lines and should look something like the figure above. Hint: use the appropriate function to perform shading
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