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

Scalar statistics


Various functions are provided by Julia's package to compute various statistics. These functions are used to describe data in different ways as required.

Standard deviations and variances

The mean and median we earlier computed (in the describe() function) are measures of central tendency. Mean refers to the center computed after applying weights to all the values and median refers to the center of the list.

This is only one piece of information and we would like to know more about the dataset. It would be good to have knowledge about the spread of data points across the dataset. We cannot use just the min and max functions as we can have outliers in the dataset. Therefore, these min and max functions will lead to incorrect results.

Variance is a measurement of the spread between data points in a dataset. It is computed by calculating the distance of numbers from the mean. Variance measures how far each number in the set is from the mean.

The following is the formula for variance...