Programming Examination #1 Frequency Analysis Solution

A.  (100 points)  Frequency Analysis

This examination consists of two parts.  The first part involves creating a short text file that must be committed and pushed to your GitHub examination repository (discussed below) prior to the Part 1 deadline on October 13. The second part requires designing and writing a single well-structured Python program that must be committed and pushed to your GitHub examination repository prior to the Part 2 deadline on October 20.

 

Late submissions will not be accepted and will result in a zero score for the exam.

 

TA help for this examination will not be provided.  If you have clarification questions, they must be addressed to the graduate TA for the class.

 

The total point value will be awarded for solutions that are complete, correct, and well structured.  A "well structured" program entails good design that employs functional decomposition, appropriate comments and general readability (descriptive names for variables and procedures, appropriate use of blank space, etc.)   If you are not sure what this means, review the "well-structured" program requirements provided in Lab2.

 

Note that your work will be graded using, and must function correctly with, the current version of Python 3 on CSE Labs UNIX machines. If you complete this programming exam using a different system, it is your responsibility to ensure it works on CSELabs machines prior to submitting it.

 

The rubric includes the following specific (accumulative) point deductions:

 

•   Missing academic integrity pledge                          -100 points

•   Syntax errors                                                             -50 to -100 points

•   Misnamed source file or incorrect repository         -25 points

•   Use of global variables                                             -25 points

•   Missing main program function                               -25 points

 

 

 

Examination Repository

Examination files must be submitted to GitHub using a special "exam repository".  Exam repositories have already been created for each registered student and are named using the string exam- followed by your X500 userID (e.g., exam-smit1234).  You must first clone your exam repository in your local home directory before submitting the materials for this exam.  If you are having difficulty, consult the second Lab from earlier in the semester or the GitHub tutorial on the class webpage.  If your exam repository is missing or something is amiss, please contact the graduate TA.  DO NOT SUBMIT YOUR EXAM FILES TO YOUR LAB/EXERCISE REPOSITORY!

Part 1 (10 points)

Using a text editor, type the following academic integrity pledge (exactly as it appears), replacing the last line with your full name and X500 ID.  Save the text file with the name academicpledge.txt and commit/push it to your GitHub examination repository:

 



 

If you do not commit and push the academicpledge.txt file prior to the deadline for Part 2, your entire examination solution will not be graded, resulting in a score of zero.  In order to receive the 10 points for Part 1, you must submit the pledge file to your exam repository prior to the deadline for part 1.

 

 

 

Part 2 (90 points)

Using Turtle graphics, write a well-structured Python program that will input a string of any length and count the occurrence of each of the vowels in the string: a,  e, i, o and u (consider y a consonant in all cases).  For example, in the string:

 

"My mama's llama pajamas are definitely not cool, especially when worn in public"

 

the letter a occurs 9 times, e, 6 times, i, 5 times, o, 4 times and u exactly once.  Note that the vowel count is case "insensitive", i.e. the characters 'E' and 'e' represent the same vowel.

 

In order to "visualize" the distribution, your program will construct and display a proportional  "pie chart" using Turtle graphics, e.g.,

Requirements:

Your program must do the following:

•   Use turtle graphics to implement the graphical interface.

•   Solicit an input string using the turtle .textinput()function.

•    Include a pure function named vowelCount(astring) that takes a single string argument, determines the individual vowel frequencies and returns the counts in a Python list, each list element corresponding to the vowels: a, e, i, o and u in order.

•    Include another non-pure function named pieChart(flist) that will accept a list of frequency counts and draw a colored pie chart as shown above.  Note that in a "pie chart", the area of each colored wedge proportionately represents the frequency value.  You may use any colors you wish.

•   You can find descriptions of the .textinput()and.write()turtle functions (along with all the

Turtle graphics module functions) here:  docs.python.org/3/library/turtle.html .

•   Use the turtle.hideturtle() method to hide the turtle.

 

 

Constraints:

•   You may use any built-in Python object class methods (string, list, etc.)

•   You may use imported functions and class methods from the turtle and math modules only

•   You may use any built-in Python functions/operations as appropriate, with the exception of input()

and print() which will not work with a graphical display environment.

 

Submission Instructions

Store all of your source code in a single module named piechart.py Make sure your files are named correctly!  Missing or misnamed submissions will not be graded and will result in a grade of zero. Commit/push your source file to your exam repository prior to the deadline for Part 2.

 

 

 

Helpful Hints:

•    You will find this project much easier if you employ the principles of "top-down, functional decomposition" as discussed in lecture and implement your program as a collection of short, simple functions.  For example, you might consider a separate function for drawing each "wedge" of the pie chart.

•    A "proportional" scale implies that individual counts are normalized so that they sum to 1.  e.g., for the following list of frequency values:

2 ,  4,  6

the first value represents 2/12 of the total count, the second value represents 4/12 of the total count and the third value represents 6/12 of the total count.  Note that this scale is easily determined by dividing each of the counts by the total count.