Description

In this project, you will analyze Twitter data to determine how people within a geographical region feel about a topic compared to people outside that region. You will define basic data structures for locations and tweets, assign sentiments to a tweet based on the words in the contains, and aggregate tweets according to location to determine the average sentiment within and outside a region.

The purpose of this project is to gain some basic literacy of Java, involving both reading and writing Java code. Unlike future projects, the classes and methods you’ll be writing are fully specified. You are required to adhere to the specifications here and in the starter code.

Authors

The project was written by Amir Kamil for EECS 285. It is based on the Twitter Trends project in the Composing Programs text.

The Twitter data in this project consists of actual tweets sent in late August and early September 2011.

Table of Contents

Project Roadmap

This is a big-picture view of what you’ll need to do to complete this project. Most of the pieces listed here also have a corresponding section later on in the spec that goes into more detail.

This project will be autograded for correctness, and the correctness portion is worth 100% of your project grade. We will not hand grade this project.

We will also run automated style and programming-practice checks on your code. However, these checks will not be worth any points on this project.

You must work alone for this project.

Download the starter code

The starter code is available at https://eecs285.github.io/p1-sentiments/starter-files.zip. The following files are included:

File(s)	Description
Sentiments.java	Data structure that maps words to sentiments
TweetReader.java	Data structure that holds tweet data read from a file
TweetAnalyzer.java	Class that analyzes tweet sentiments. You will need to complete this class.
TweetSentimentMain.java	Main driver for tweet-sentiment analysis
Test.java	Basic tests for Location and Tweet clases
Test.correct	Correct output from running Test
data/	Directory containing sentiment data ( sentiments.csv ) and tweet data ( *.txt )
obama.correct soup.correct texas.correct	Correct output from running sentiment analysis on obama.txt , soup.txt , and texas.txt

Extract the files to a temporary directory.

Set up your project

Follow the setup tutorial to set up your project.

Your Java files should all be in a package with the structure eecs285.proj1.<uniqname> , where

<uniqname> is your uniqname. For example, I would put the following package directive at the top of each .java file: package eecs285.proj1.akamil;

You will need to modify each of the starter files so that they have the correct package directive at the top.

Familiarize yourself with the starter code

Read through the starter code to understand what classes and methods are available. You need only read through the documentation; you do not have to understand how the starter code works.

Understand what you need to write

Read through the rest of the specification to determine what classes you must complete or write from scratch.

Implement and test your classes and methods

Implement the required classes and methods. Start by writing stubs, empty implementations (or just a trivial return for non-void methods) of the methods you need to write, so that the code will compile. Then write the actual implementation of each method, testing along the way.

In addition to the provided tests, you should write your own, as the tests in the starter code do not fully test the code you will write.

Submit

Submit the following files to the autograder.

Location.java

Tweet.java

TweetAnalyzer.java

Do not submit Test.java or TweetSentimentMain.java . We will use our own versions of these files, so make sure that your implementation does not require them to be modified.

As per course policy, we will grade your last submission to the autograder. It is your responsibility to ensure that your last submission is complete.

The Location Class

The Location class represents a geographical location, with a given latitude and longitude. You will need to create a file Location.java . Place the appropriate package directive at the top and define a public class Location . This class should have the following fields (data members):

A double to represent the latitude.

A double to represent the longitude.

It should also have the following public methods:

A constructor that takes in a latitude and longitude and initializes the fields. You do not have to do any error checking on latitude or longitude values.

A method getLatitude() that returns the latitude of the location.

A method getLongitude() that returns the longitude of the location.

A toString() method with the following signature:

@Override

public String toString();

This method should return a string representation of the location, in the following format:

[<latitude>, <longitude>]

For instance, the Location with latitude 42.28 and longitude -83.75 would return the string:

“[42.28, -83.75]”

A method with the following signature: public boolean isWithin(Location lowerBound, Location upperBound);

This method should return true if the location’s latitude is between that of lowerBound and upperBound , inclusive, and the location’s longitude is also between that of lowerBound and upperBound . It should return false otherwise.

Once you have written the Location class, you should test it to make sure it is correct. We have provided a basic test as part of Test.java . You will need to write stubs for Tweet.java in order for the code to compile.

The Tweet Class

The Tweet class represents an individual tweet, keeping track of both the location where the tweet originated and the content of the tweet. You will need to create a file Tweet.java , with the appropriate package directive and a public class Tweet . The class should have the following fields:

A String to represent the content of the tweet.

A Location to represent the geographical location of the tweet.

You will need to define the following public methods:

A constructor that takes in a String representing the content, a double latitude, and a double longitude.

A method getText() that returns the content of the tweet.

A method getLocation() that returns the location of the tweet.

A toString() method that returns a string representation of the tweet. This should just be the location and content separated by a space. For example:

“[42.28, -83.75] i love my job. #winning”  A method with the following signature: public ArrayList<String> getWords();

You will need an import statement after the package directive: import java.util.ArrayList;

The getWords() method should return a list of the individual words in the tweet. For the purposes of this project, a word is a consective sequence of ASCII letters, i.e. characters in the range [a, z] or [A, Z] . You can use the charAt() method of String to obtain an individual character, and then you can compare the character to the literals ‘a’ , ‘z’ , ‘A’ ,

‘Z’ to determine if it falls in either range. For the tweet above, the individual words are “i” , “love” , “my” , “job” , and “winning” .

You will need to construct individual String s for each word. You can use the + or += operators to construct a String incrementally.

Read through the documentation for ArrayList to determine how to use it. (We are using String in place of the type E in the documentation.)

The TweetAnalyzer Class

The TweetAnalyzer class analyzes the sentiment of tweets. Part of the class is already written for you. You will need to fill in the implementation of the following methods:

computeSentiment() , which computes the sentiment of an individual tweet. You will need to

retrieve the words from the tweet and then compute the average sentiment of words in the tweet. Ignore any words with a sentiment of zero. Read through the documentation for the Sentiments class to determine how to obtain the sentiment of a word.

The return type of computeSentiment() is Double , a “boxed” version of double that is an object rather than a primitive. This allows us to return null for tweets that do not have a word with a sentiment, which is distinct from a tweet with both positive and negative words that average out to a sentiment of zero.

averageSentimentWithin() computes the average sentiment of tweets within the given

geographic area. It should ignore tweets that have no sentiment (those for which

computeSentiment() returns null ) and tweets outside the geographic area.

If there are no tweets with sentiment within the geographic area, the method should print out the following:

No tweets with sentiment

There should be two spaces before the word No , and the print should end with a newline.

If there are tweets with sentiment within the geographic area, the method should print out the following:

Average sentiment over <count> tweets: <sentiment>

There should be two spaces before the word Average , and the print should end with a newline. <count> should be the number of tweets within the geographic area that have sentiment. <sentiment> should be the average sentiment of those tweets, rounded to four digits after the decimal: use the roundedString() method to convert a double to the appropriate rounded string.

averageSentimentOutside() computes the average sentiment of tweets outside the given

geographic area. It should behave the same as averageSentimentWithin() , except that it considers the tweets outside the area rather than within it.

The TweetSentimentMain Class

The TweetSentimentMain class is the top-level driver for the analysis. Given a tweet file, it computes the average sentiment within an approximation of the Midwest region, as well as the average sentiment outside of it:

Along with changing the package directive, you will need to set the UNIQNAME constant to be your uniqname, so that the code can load data files from the proper location. Initially, the

TWEET_FILE constant is set to “soup.txt” , so that the program analyzes tweet data concerning “soup”. You can change the constant to one of the other data files in the data/ directory, or you can specify the tweet file at the command line:

$ java eecs285.proj1.akamil.TweetSentimentMain obama.txt

(Of course, you should replace akamil with your own uniqname.)

You can also specify the command-line arguments in IntelliJ, as described in the setup tutorial.

We have provided correct output files for a subset of the tweet-data files. For instance, the following is the result of running the analysis on obama.txt , which contains tweets with the word “obama” in them:

Tweet file: obama.txt

Location boundary: [37.0, -104.05] to [49.0, -80.517]

Sentiment within boundary:

Average sentiment over 129 tweets: 0.0391

Sentiment outside boundary:

Average sentiment over 627 tweets: 0.0088

Given the dataset, it appears that people within the Midwest had a slightly higher opinion of

“obama” than those outside the Midwest. Perhaps because President Obama is from Chicago?

Requirements and Restrictions

You must follow the specifications in here and in the starter code exactly. This project will be autograded, so any deviation from the specifications will likely result in a 0.

You may not use any Java library classes except ArrayList , Double , and String .

You may not and any fields to your classes, other than those described in the spec.

You may add private helper methods, but you may not add any non-private methods.