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

Discovering groups of data using K-means clustering


One of the most popular and well-known clustering methods is K-means clustering. It's conceptually simple. It's also easy to implement and computationally cheap. We can get decent results quickly for many different datasets.

On the downside, it sometimes gets stuck in local optima and misses a better solution altogether.

Generally, K-means clustering works best when groups in the data are spatially distinct. This means that if the natural groups in the data overlap, the clusters that K-means generates will not properly distinguish the natural groups in the data.

Getting ready

For this recipe, we'll need the same dependencies in our project.clj file that we used in the Loading CSV and ARFF files into Weka recipe.

We'll need a slightly different set of imports in our script or REPL, however.

(import [weka.core EuclideanDistance]
        [weka.clusterers SimpleKMeans])

For data, we'll use the Iris dataset, which is often used for learning about...