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

Benchmarking with Criterium


Benchmarking can be an important part of the data analysis process. Especially when faced with very large datasets that need to be processed in multiple ways, choosing algorithms that will finish in a reasonable amount of time is important. Benchmarking gives us an empirical basis on which to make these decisions.

For some of the recipes in this chapter, we've used the time macro. For others we've used the Criterium library (https://github.com/hugoduncan/criterium). Why would we want to go to the trouble of using a whole library, just to see how fast our code is?

Generally, when we want to benchmark our code, we'll often start by using something like the time macro. This means:

  1. Get the start time.

  2. Execute the code.

  3. Get the end time.

If you've done this often, you will realize that this has a number of problems, especially for benchmarking small functions that execute quickly. The times are often inconsistent, and they can be dependant on a number of factors external...