Book Image

Applied Unsupervised Learning with R

By : Alok Malik, Bradford Tuckfield
Book Image

Applied Unsupervised Learning with R

By: Alok Malik, Bradford Tuckfield

Overview of this book

Starting with the basics, Applied Unsupervised Learning with R explains clustering methods, distribution analysis, data encoders, and features of R that enable you to understand your data better and get answers to your most pressing business questions. This book begins with the most important and commonly used method for unsupervised learning - clustering - and explains the three main clustering algorithms - k-means, divisive, and agglomerative. Following this, you'll study market basket analysis, kernel density estimation, principal component analysis, and anomaly detection. You'll be introduced to these methods using code written in R, with further instructions on how to work with, edit, and improve R code. To help you gain a practical understanding, the book also features useful tips on applying these methods to real business problems, including market segmentation and fraud detection. By working through interesting activities, you'll explore data encoders and latent variable models. By the end of this book, you will have a better understanding of different anomaly detection methods, such as outlier detection, Mahalanobis distances, and contextual and collective anomaly detection.
Table of Contents (9 chapters)

Summary


In this chapter, we discussed the idea of the dimensionality of data. We went over why it could be useful to reduce the dimensionality of data and highlighted that the process of dimension reduction can reveal important truths about the underlying structure of data. We covered two important dimension reduction methods. The first method we discussed was market basket analysis. This method is useful for generating associative rules from complex data and can be used for the use case it was named after (analyzing baskets of groceries) or a wide variety of other applications (such as analyzing the clustering of survey responses). We also discussed PCA, a common way to describe data in terms of linear combinations of its dimensions. PCA is easy to perform with some linear algebra tools, and provides an easy way to approximate even very complex data.

In the next chapter, we will have a look at the different data comparison methods.