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

Understanding decision trees


A decision tree is a very good example of "divide and conquer". It is one of the most practical and widely used methods for inductive inference. It is a supervised learning method that can be used for both classification and regression. It is non-parametric and its aim is to learn by inferring simple decision rules from the data and create such a model that can predict the value of the target variable.

Before taking a decision, we analyze the probability of the pros and cons by weighing the different options that we have. Let's say we want to purchase a phone and we have multiple choices in the price segment. Each of the phones has something really good, and maybe better than the other. To make a choice, we start by considering the most important feature that we want. And as such, we create a series of features that it has to pass to become the ultimate choice.

In this section, we will learn about:

  • Decision trees

  • Entropy measures

  • Random forests

We will also learn about...