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

Chapter 2. Data Munging

It is said that around 50% of the data scientist's time goes into transforming raw data into a usable format. Raw data can be in any format or size. It can be structured like RDBMS, semi-structured like CSV, or unstructured like regular text files. These contain some valuable information. And to extract that information, it has to be converted into a data structure or a usable format from which an algorithm can find valuable insights. Therefore, usable format refers to the data in a model that can be consumed in the data science process. This usable format differs from use case to use case.

This chapter will guide you through data munging, or the process of preparing the data. It covers the following topics:

  • What is data munging?

  • DataFrames.jl

  • Uploading data from a file

  • Finding the required data

  • Joins and indexing

  • Split-Apply-Combine strategy

  • Reshaping the data

  • Formula (ModelFrame and ModelMatrix)

  • PooledDataArray

  • Web scraping