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

Tracking processing with watchers


Another tool that Clojure provides for working with agents is watchers. These are just functions that get a chance to peek at the agent's data. This happens after the validators have successfully run and the new data is set as the agent's state. Because of the way it's handled, the state may have changed again since then, but watchers give you the chance to look at and track the data separately.

This can help us keep an eye on the data as it's being processed. We can use it to log progress, sample the data for manual validation, or for a number of other tasks.

Getting ready

We'll use the dependencies and requirements that we did in the Managing program complexity with STM recipe. We'll also add a new import.

(import '[java.lang Thread])

And we'll use the data file from the Managing program complexity with STM recipe, and the lazy-read-csv and with-header functions from that recipe.

From the Maintaining data consistency with validators recipe, we'll use the int...