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

Measures of variation


It is good to have knowledge of the variation of values in the dataset. Various statistical functions facilitate:

  • span(arr): span is used to calculate the total spread of the dataset, which is maximum(arr) to minimum(arr):

  • variation(arr): Also called the coefficient of variance. It is the ratio of the standard deviation to the mean of the dataset. In relation to the mean of the population, CV denotes the extent of variability. Its advantage is that it is a dimensionless number and can be used to compare different datasets.

Standard error of mean: We work on different samples drawn from the population. We compute the means of these samples and call them sample means. For different samples, we wouldn't be having the same sample mean but a distribution of sample means. The standard deviation of the distribution of these sample means is called standard error of mean.

In Julia, we can compute standard error of mean using sem(arr).

Mean absolute deviation is a robust measure...