Book Image

Julia for Data Science

By : Anshul Joshi
2 (1)
Book Image

Julia for Data Science

2 (1)
By: Anshul Joshi

Overview of this book

Julia is a fast and high performing language that's perfectly suited to data science with a mature package ecosystem and is now feature complete. It is a good tool for a data science practitioner. There was a famous post at Harvard Business Review that Data Scientist is the sexiest job of the 21st century. (https://hbr.org/2012/10/data-scientist-the-sexiest-job-of-the-21st-century). This book will help you get familiarised with Julia's rich ecosystem, which is continuously evolving, allowing you to stay on top of your game. This book contains the essentials of data science and gives a high-level overview of advanced statistics and techniques. You will dive in and will work on generating insights by performing inferential statistics, and will reveal hidden patterns and trends using data mining. This has the practical coverage of statistics and machine learning. You will develop knowledge to build statistical models and machine learning systems in Julia with attractive visualizations. You will then delve into the world of Deep learning in Julia and will understand the framework, Mocha.jl with which you can create artificial neural networks and implement deep learning. This book addresses the challenges of real-world data science problems, including data cleaning, data preparation, inferential statistics, statistical modeling, building high-performance machine learning systems and creating effective visualizations using Julia.
Table of Contents (17 chapters)
Julia for Data Science
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface

Data visualization using Gadfly


Gadfly is an exhaustive plotting and data visualization package written in Julia by Daniel Jones. It is based on the book, The Grammar of Graphics, by Leland Wilkinson. It is largely inspired by ggplot2 for R, which is another amazing package for plotting and visualizations.

Installing Gadfly

Installation is straightforward as it is a registered Julia package:

Julia> Pkg.update()
Julia> Pkg.add("Gadfly")

This will also install a few other packages needed by Gadfly.

To use Gadfly, run this line:

Julia> using Gadfly

We will use IJulia (jupyter notebook) in our examples.

Gadfly has the capability to render high-quality graphics and visualizations in PNG, SVG, Postscript, and PDF. Embedded JavaScript is used by the SVG backend, which provides interactivity with the graphics such as zooming, panning, and toggling.

It is good to have Cairo installed, as it is needed by PNG, PostScript, and PDF:

Julia> Pkg.add("Cairo")

Suppose we create an exampleplot. To...