Book Image

Clojure Data Analysis Cookbook

By : Eric Rochester
Book Image

Clojure Data Analysis Cookbook

By: Eric Rochester

Overview of this book

<p>Data is everywhere and it's increasingly important to be able to gain insights that we can act on. Using Clojure for data analysis and collection, this book will show you how to gain fresh insights and perspectives from your data with an essential collection of practical, structured recipes.<br /><br />"The Clojure Data Analysis Cookbook" presents recipes for every stage of the data analysis process. Whether scraping data off a web page, performing data mining, or creating graphs for the web, this book has something for the task at hand.<br /><br />You'll learn how to acquire data, clean it up, and transform it into useful graphs which can then be analyzed and published to the Internet. Coverage includes advanced topics like processing data concurrently, applying powerful statistical techniques like Bayesian modelling, and even data mining algorithms such as K-means clustering, neural networks, and association rules.</p>
Table of Contents (18 chapters)
Clojure Data Analysis Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Complex queries with Cascalog


So far we've seen very basic Cascalog predicates and queries. We've seen queries that pull data from one source generator and maybe include one predicate test. In this recipe, we'll see several more complex queries.

Getting ready

For this recipe, we'll need the dependencies from the Distributed processing with Cascalog and Hadoop recipe. We'll also use the Doctor Who companion data that we defined in that recipe. The source code for this data is available in the code for the book, and you can also download just the code to create this dataset from http://www.ericrochester.com/clj-data-analysis/data/companions.clj.

How to do it…

We'll start with simple queries and build up from there.

  1. First, let's look at a simple join:

    user=> (?<- (stdout) [?name ?dr]
          (full-name ?c ?name) (doctor ?c ?dr))
    …
    RESULTS
    -----------------------
    Ace     7
    Adam Mitchell   9
    Adelaide Brooke 10
    Adric   4
    Adric   5
    Amy Pond        11
    Astrid Peth     10
    …

    This pulls each companion...