Chapter 1, Network Analysis – The Six Degrees of Kevin Bacon, will discuss how people are socially organized into networks. These networks are reified in interesting ways in online social networks. We'll take the opportunity to get a small dataset from an online social network and analyze and look at how people are related in it.

Chapter 2, GIS Analysis – Mapping Climate Change, will explore how we can work with geographical data. It also walks us through getting the weather data and tying it to a geographical location. It then involves analyzing nearby points together to generate a graphic of a simplified and somewhat naive notion of how climate has changed over the period the weather has been tracked.

Chapter 3, Topic Modeling – Changing Concerns in the State of the Union Addresses, will address how we can scrape free text information off the Internet. It then uses topic modeling to look at the problems that presidents have faced and the themes that they've addressed over the years.

Chapter 4, Classifying UFO Sightings, will take a look at UFO sightings and talk about different ways to explore and get a grasp of what's in the dataset. It will then classify the UFO sightings based on various attributes related to the sightings as well as their descriptions.

Chapter 5, Benford's Law – Detecting Natural Progressions of Numbers, will take a look at the world population data from the World Bank data site. It will discuss Benford's Law and how it can be used to determine whether a set of numbers is naturally generated or artificially or randomly constructed.

Chapter 6, Sentiment Analysis – Categorizing Hotel Reviews, will take a look at the problems and possibilities related to sentiment analysis tasks. These are typically difficult and fraught categorizations of documents based on a notion of positive or negative. In this chapter, we'll also take a look at categorizing, both manually and automatically, a dataset of hotel reviews.

Chapter 7, Null Hypothesis Tests – Analyzing Crime Data, will take a look at planning, constructing, and performing null-hypothesis tests for statistical significance. It will use international crime data to look at the relationship between economic indicators and some types of crime.

Chapter 8, A/B Testing – Statistical Experiments for the Web, will take a look at how to determine which version of a website engages with the users in a better way. Although conceptually simple, this task does have a few pitfalls and danger points to be aware of.

Chapter 9, Analyzing Social Data Participation, will take a look at how people participate in online social networks. We will discuss and demonstrate some ways to analyze this data with an eye toward encouraging more interaction, contributions, and participation.

Chapter 10, Modeling Stock Data, will take a look at how to work with time-series data, stock data, natural language, and neural networks in order to find relationships between news articles and fluctuations in stock prices.

One piece of software required for this book is JDK, which you can get from http://www.oracle.com/technetwork/java/javase/downloads/index.html. JDK is necessary to run and develop on the Java platform.

The other major piece of software that you'll need is Leiningen 2, which you can download and install from https://github.com/technomancy/leiningen. Leiningen 2 is a tool that is used to manage Clojure projects and their dependencies. It's quickly becoming the de facto standard project tool in the Clojure community.

Throughout this book, we'll use a number of other Clojure and Java libraries, including Clojure itself. Leiningen will take care of downloading these for us as and when we need them.

You'll also need a text editor or Integrated Development Environment (IDE). If you already have a text editor that you like, you can probably use it. Refer to http://dev.clojure.org/display/doc/Getting+Started for tips and plugins to use your particular favorite environment. If you don't have a preference, I'd suggest that you look at using Eclipse with Counterclockwise. There are instructions to get this setup at http://dev.clojure.org/display/doc/Getting+Started+with+Eclipse+and+Counterclockwise.

If you are a programmer or data scientist who is familiar with Clojure and wants to use it in your data analysis processes, this book is for you. This isn't a tutorial on Clojure—there are already a number of excellent introductory books out there—so you'll need to be familiar with the language; however, you don't need to be an expert at it.

Likewise, you don't need to be an expert on data analysis, although you should probably be familiar with its tasks, processes, and techniques. While you might be able to gain enough from these case studies to get started, you'll want to get a more thorough introduction to this field to be truly effective.

In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "However, before we start looking at the code, let's check out the Leiningen 2 project.clj file."

A block of code is set as follows:

(ns network-six.graph
  (:require [clojure.set :as set]
            [clojure.core.reducers :as r]
            [clojure.data.json :as json]
            [clojure.java.io :as io]
            [clojure.set :as set]
            [network-six.util :as u]))

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

  clojure.lang.PersistentStructMap
  (extract-text [x]
      (concat
        (extract-text (:content x))
        (when (contains? #{:span :p} (:tag x))
          ["\n\n"])))

Any command-line input or output is written as follows:

$ cd www
$ python -m SimpleHTTPServer
Serving HTTP on 0.0.0.0 port 8000 …

New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: "Right-click on the new layer and select Properties."

Feedback from our readers is always welcome. Let us know what you think about this book—what you liked or may have disliked. Reader feedback is important for us to develop titles that you really get the most out of.

To send us general feedback, simply send an e-mail to <[email protected]>, and mention the book title via the subject of your message.

If there is a topic that you have expertise in and you are interested in either writing or contributing to a book, see our author guide on www.packtpub.com/authors.

Now that you are the proud owner of a Packt book, we have a number of things to help you to get the most from your purchase.