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

K-means clustering


K-means is the most popular of the clustering techniques because of its ease of use and implementation. It also has a partner by the name of K-medoid. These partitioning methods create level-one partitioning of the dataset. Let's discuss K-means in detail.

K-means algorithm

K-means start with a prototype. It takes centroids of data points from the dataset. This technique is used for the objects lying in the n-dimensional space.

The technique involves choosing the K number of centroids. This K is specified by the user and is chosen considering various factors. It defines how many clusters we want. So, choosing a higher or lower than the required K can lead to undesired results.

Now going forward, each point is assigned to its nearest centroid. As many points get associated with a specific centroid, a cluster is formed. The centroid can get updated depending on the points that are part of the current cluster.

This process is done repeatedly until the centroid gets constant.

Algorithm...