Book Image

R Data Analysis Projects

Book Image

R Data Analysis Projects

Overview of this book

R offers a large variety of packages and libraries for fast and accurate data analysis and visualization. As a result, it’s one of the most popularly used languages by data scientists and analysts, or anyone who wants to perform data analysis. This book will demonstrate how you can put to use your existing knowledge of data analysis in R to build highly efficient, end-to-end data analysis pipelines without any hassle. You’ll start by building a content-based recommendation system, followed by building a project on sentiment analysis with tweets. You’ll implement time-series modeling for anomaly detection, and understand cluster analysis of streaming data. You’ll work through projects on performing efficient market data research, building recommendation systems, and analyzing networks accurately, all provided with easy to follow codes. With the help of these real-world projects, you’ll get a better understanding of the challenges faced when building data analysis pipelines, and see how you can overcome them without compromising on the efficiency or accuracy of your systems. The book covers some popularly used R packages such as dplyr, ggplot2, RShiny, and others, and includes tips on using them effectively. By the end of this book, you’ll have a better understanding of data analysis with R, and be able to put your knowledge to practical use without any hassle.
Table of Contents (15 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Chapter 3. Collaborative Filtering

Given a database of user ratings for products, where a set of users have rated a set of products, collaborative filtering algorithms can give ratings for products yet to be rated by a particular user. This leverages the neighborhood information of the user to provide such recommendations. The input to collaborative filtering is a matrix, where the rows are users and the columns are items. Cell values are the ratings provided by the user for a product. Ratings of products are ubiquitous in today's internet world. IMDB, Yelp, Amazon, and similar systems today have a rating system deployed to capture user preferences. Preferences are typically captured by a rating system, where the ratings are defined as stars or a points system.

Based on the underlying technology, collaborative filtering can be:

  • An online system, where the whole user product preference matrix is loaded into the memory to make recommendations for a user and his yet to be rated product combination...