Book Image

Applied Supervised Learning with R

By : Karthik Ramasubramanian, Jojo Moolayil
Book Image

Applied Supervised Learning with R

By: Karthik Ramasubramanian, Jojo Moolayil

Overview of this book

R provides excellent visualization features that are essential for exploring data before using it in automated learning. Applied Supervised Learning with R helps you cover the complete process of employing R to develop applications using supervised machine learning algorithms for your business needs. The book starts by helping you develop your analytical thinking to create a problem statement using business inputs and domain research. You will then learn different evaluation metrics that compare various algorithms, and later progress to using these metrics to select the best algorithm for your problem. After finalizing the algorithm you want to use, you will study the hyperparameter optimization technique to fine-tune your set of optimal parameters. The book demonstrates how you can add different regularization terms to avoid overfitting your model. By the end of this book, you will have gained the advanced skills you need for modeling a supervised machine learning algorithm that precisely fulfills your business needs.
Table of Contents (12 chapters)
Applied Supervised Learning with R
Preface

Variable Clustering


Variable clustering is used for measuring collinearity, calculating redundancy, and for separating variables into clusters that can be counted as a single variable, thus resulting in data reduction. Hierarchical cluster analysis on variables uses any one of the following: Hoeffding's D statistics, squared Pearson or Spearman correlations, or uses as a similarity measure the proportion of observations for which two variables are both positive. The idea is to find the cluster of correlated variables that are correlated with themselves and not with variables in another cluster. This reduces a large number of features into a smaller number of features or variable clusters.

Exercise 86: Using Variable Clustering

In this exercise, we will use feature clustering for identifying a cluster of similar features. From each cluster, we can select one or more features for the model. We will use the hierarchical cluster algorithm from the Hmisc package in R. The similarity measure should...