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 7. Unsupervised Machine Learning

In the previous chapter, we learned about supervised machine learning algorithms and how we can use them in real-world scenarios.

Unsupervised learning is a little bit different and harder. The aim is to have the system learn something, but we ourselves don't know what to learn. There are two approaches to the unsupervised learning.

One approach is to find the similarities/patterns in the datasets. Then we can create clusters of these similar points. We make the assumption that the clusters that we found can be classified and can be provided with a label.

The algorithm itself cannot assign names because it doesn't have any. It can only find the clusters based on the similarities, but nothing more than that. To actually be able to find meaningful clusters, a good size of dataset is required.

It is used extensively in finding similar users, recommender systems, text classification, and so on.

We will discuss various clustering algorithms in detail. In this...