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

Visualizing using Vega


Vega is a beautiful visualization library provided by John Myles White. It is available as a registered Julia package, so it can be installed easily.

It is built on top of D3.js and uses JSON to create beautiful visualizations. It requires an Internet connection whenever we need to generate graphs as it doesn't store local copies of the JavaScript libraries needed.

Installation

To install Vega, use the following commands:

Pkg.add("Vega")
using Vega

Examples

Let's walk through various visualizations using Vega.

Scatterplot

Following are the arguments of a scatterplot:

  •  x and y: AbstractVector

  • Group: AbstractVector

Scatterplots are used to determine the correlation between two variables, that is, how one is affected by the other:

scatterplot(x=rand(100), y=rand(100))

We can now move on to building a complex scatterplot:

This will generate the following scatterplot. We can clearly see two clusters generated by Vega. These are d1 and d2:

In this particular example, we grouped...