CSE142—Computer Programming I

Programming Assignment #7

Due: Tuesday, 5/19/09, 9 pm

This assignment focuses on arrays and file processing. Turn in a file named PersonalityTest.java. You also need input file personality.txt from the course web site.

The assignment involves processing data from a personality test. There is a link on the course web site where you can take the personality test (this is optional). Student answers will be included in a data file distributed to the whole class.

Background Information:

The Keirsey Temperament Sorter (http://www.keirsey.com/) is a personality test that involves answering 70 questions. Each question has two answer choices, which we will refer to as the 'A' and 'B' answer. The person taking the test can leave a question blank, in which case the answer will be recorded with a dash ('-').

The Keirsey test measures four independent dimensions of personality:

1. Extrovert versus Introvert (E vs. I): what energizes you
2. Sensation versus iNtuition (S vs. N): what you focus on
3. Thinking versus Feeling (T vs. F): how you interpret what you focus on
4. Judging versus Perceiving (J vs. P): how you approach life

Individuals are categorized on one side or the other for each dimension. The corresponding letters are put together to form a personality type. For example, if you are an Extrovert, iNtuitive, Thinking, Perceiving person, then you are referred to as an ENTP. The 'A' answers correspond to E, S, T, and J (the left-hand choices above) and the 'B' answers correspond to I, N, F, and P (the right-hand choices above). For each dimension, we determine a percentage (0-100) of 'B' answers the user gave for that dimension to indicate whether the person is closer to the 'A' or 'B' side.

Suppose that someone's answers are as follows. (These are the answers given by "Betty Boop" below.)

Dimension	# of A answers	# of B answers	% of B answers	Result
Extrovert/Introvert	1	9	90%	I
Sensing/iNtuition	17	3	15%	S
Thinking/Feeling	18	2	10%	T
Judging/Perceiving	18	2	10%	J

We add up how many of each type of answer we got for each dimension. Then we compute the percentage of B answers for each dimension. Then we assign letters based on which side the person ends up on for each dimension. In the Extrovert/Introvert dimension, for example, Betty gave 9 B answers out of 10 total (90%), which means she is on the B side, which is "Introvert" or I. The overall percentages are [90, 15, 10, 10], which works out to a personality type of ISTJ.

Mechanics of the Personality Test:

Suppose that "Betty Boop" gave the following answers for the 70 questions, in order from 1 to 70:

BABAAAABAAAAAAABAAAABBAAAAAABAAAABABAABAAABABABAABAAAAAABAAAAAABAAAAAA

The questions are organized into 10 groups of 7 questions, with the following repeating pattern in each group:

1. The first one question in each group is an Introvert/Extrovert question (questions 1, 8, 15, 22, etc.)
2. The next two questions are for Sensing/iNtuition (questions 2 and 3, 9 and 10, 16 and 17, 23 and 24, etc.)
3. The next two questions are for Thinking/Feeling (questions 4 and 5, 11 and 12, 18 and 19, 25 and 26, etc.)
4. The next two questions are for Judging/Perceiving (questions 6 and 7, 13 and 14, 20 and 21, 27 and 28, etc.)

In other words, if we consider the I/E to be dimension 1, the S/N to be dimension 2, the T/F to be dimension 3, and the J/P to be dimension 4, the map of questions to their respective dimensions would look like this (spaces added for emphasis):

1223344 1223344 1223344 1223344 1223344 1223344 1223344 1223344 1223344 1223344

BABAAAA BAAAAAA ABAAAAB BAAAAAA BAAAABA BAABAAA BABABAA BAAAAAA BAAAAAA BAAAAAA

Notice that there are half as many Introvert/Extrovert questions as there are for the other three dimensions.

Input Data:

The personality data consists of line pairs, one per person. The first line has the person’s name, and the second has the person's 70 answers ('A', 'B' or '-'). The A or B can be either uppercase or lowercase. A dash means a question was skipped by that person, as seen in Han Solo's data below.

Input file personality.txt (partial):

Betty Boop

BABAAAABAAAAAAABAAAABBAAAAAABAAAABABAABAAABABABAABAAAAAABAAAAAABAAAAAA

Bugs Bunny

aabaabbabbbaaaabaaaabaaaaababbbaabaaaabaabbbbabaaaabaabaaaaaabbaaaaabb

Han Solo

BA-ABABBB-bbbaababaaaabbaaabbaaabbabABBAAABABBAAABABAAAABBABAAABBABAAB

Program Behavior:

Your program's output begins with an introduction of your own creation, such as an explanation of the personality test and/or a fact about your own type. Next your program asks for the input file name to process. You may assume that the user will type a name of a file that exists and can be read. Next the program prompts the user for an output file name; if this file already exists, your program will overwrite its contents. (This is the default PrintStream behavior.)

Log of execution (user input underlined):

<< your introduction message here >>

Input file name: personality.txt

Output file name: output.txt

Do not hard-code file names in your code. The input file name used in the above log is personality.txt, but the input file could have a different name. You should not need the string "personality.txt" anywhere in your program's code. Similarly, the output file name happens to be named output.txt in the log shown on this page, but this will not always be the case, and your code should not contain the string "output.txt".

Each pair of lines from the input file is turned into a group of lines in the output file with the name, count of As and Bs for each dimension, % Bs for each dimension (rounded to the nearest whole percent), and personality type. Questions left blank (indicated by a dash) do not contribute to the count of As/Bs, nor to the percent Bs for that dimension. If the person has the same number of As and Bs for a dimension, give them an "X", as with Han Solo below. Assume that the input file is valid, has no errors or illegal data, and that nobody has skipped all questions for a dimension (it would be impossible to determine a percentage in such a case). Reproduce the following output format:

Output file output.txt (partial):

Betty Boop

Answers: [1A-9B, 17A-3B, 18A-2B, 18A-2B]

Percent B: [90, 15, 10, 10]

Type: ISTJ

Bugs Bunny

Answers: [8A-2B, 11A-9B, 17A-3B, 9A-11B]

Percent B: [20, 45, 15, 55]

Type: ESTP

Han Solo

Answers: [2A-8B, 9A-9B, 11A-9B, 15A-5B]

Percent B: [80, 50, 45, 25]

Type: IXTJ

Implementation Guidelines and Hints:

A major purpose of this assignment is to test your understanding of arrays. Therefore you should use arrays to store the various data for each of the four dimensions of the personality test, and to transform data from one form to another. There are three major transformations you should perform: from the original 70 A/B answers to counts of As and Bs; from counts to percentages of Bs; and from percentages to a four-letter personality type string. These transformations are summarized by the following diagram using Han Solo's data:

Answers: "BA-ABABBB-bbbaababaaaabbaaabbaaabbabABBAAABABBAAABABAAAABBABAAABBABAAB"

What is computed Resulting output

A/B count: {2, 9, 11, 15}, {8, 9, 9, 5} Answers: [2A-8B, 9A-9B, 11A-9B, 15A-5B]

B percent: {80, 50, 45, 25} Percent B: [80, 50, 45, 25]

Type: "IXTJ" Type: IXTJ

To count As and Bs, read data from the input file one line at a time using Scanner's nextLine method. Analyze each character within the overall line String as a char value using the line string's charAt method.

When counting As and Bs, you should avoid redundancy and keep the counts for each of the four dimensions correctly. The mod operator is useful for computing what dimension is relevant.

The Arrays.toString method is useful for producing some of your output.

For producing the percentage as a rounded whole number, you can cast to an int like this:

int percent = (int)(percentage + 0.5);

Your program must produce file output, but you can delay this part of the assignment by initially by printing all output to the console. Then, once you have the program logic working, you can add produce file output by using a PrintStream object you create rather than System.out.

Style Guidelines:

Use a class constant in your program representing the number of dimensions in the test, as an int (with a value of 4). It will not be possible to change this constant and have the program adjust, but it makes the code more readable.

We will grade your method structure very strictly on this assignment. Methods should use parameters and returns, including passing and returning arrays, as appropriate. The methods should be well-structured and avoid redundancy. No one method should do too large a share of the overall task. Chapter 7's Case Study program in textbook section 7.5 is a good example of how to write a larger program with several methods that use arrays as parameters.

Your main method should be a concise summary of the overall program. It is okay for main to contain some code such as println statements, or for main to open files and perform some file I/O. But the main method should not perform too large a share of the overall work itself, such as examining each of the 70 characters of a person's answers to the personality test. Also avoid "chaining," which is when many methods call each other without ever returning to main. As a rough guide you need not match exactly, our solution is around 100-120 lines long and has 5 methods besides main.

We will also check strictly for redundancy on this assignment. If you have a very similar piece of code that is repeated several times in your program, eliminate the redundancy by creating a method, by using for loops over the elements of arrays, and/or by factoring if/else code as described in Section 4.3 of the textbook.

You are limited to features in Chapters 1 through 7. Follow past style guidelines such as indentation, names, variables, types, line lengths, and comments (at the beginning of your program, on each method, and on complex sections of code).