Book Image

R Data Science Essentials

Book Image

R Data Science Essentials

Overview of this book

With organizations increasingly embedding data science across their enterprise and with management becoming more data-driven it is an urgent requirement for analysts and managers to understand the key concept of data science. The data science concepts discussed in this book will help you make key decisions and solve the complex problems you will inevitably face in this new world. R Data Science Essentials will introduce you to various important concepts in the field of data science using R. We start by reading data from multiple sources, then move on to processing the data, extracting hidden patterns, building predictive and forecasting models, building a recommendation engine, and communicating to the user through stunning visualizations and dashboards. By the end of this book, you will have an understanding of some very important techniques in data science, be able to implement them using R, understand and interpret the outcomes, and know how they helps businesses make a decision.
Table of Contents (15 chapters)
R Data Science Essentials
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Centroid-based clustering and an ideal number of clusters


Centroid-based clustering is a method in which each cluster is represented by a central vector, and the objects are assigned to the clusters based on the proximity such that the squared distance from the central vector is minimized.

In this section, we will create the clusters using the K-means algorithm. We will see the implementation of this using R.

We need to use the fpc package called flexible procedure for the clustering in order to implement various clustering algorithms in R:

install.packages("fpc")
library(fpc)

Before creating the clusters using the K-means algorithm, we need to identify the ideal number of clusters for the given dataset. We can get the ideal number of clusters using the pamk function, where we do partitioning around the medoids to compute the ideal number of clusters. The clusters$nc variable will hold the ideal number of clusters:

clusters<- pamk(wdata)
n <- clusters$nc
n
[1] 5

The n vector will hold...