Book Image

Machine Learning with R - Fourth Edition

By : Brett Lantz
5 (1)
Book Image

Machine Learning with R - Fourth Edition

5 (1)
By: Brett Lantz

Overview of this book

Dive into R with this data science guide on machine learning (ML). Machine Learning with R, Fourth Edition, takes you through classification methods like nearest neighbor and Naive Bayes and regression modeling, from simple linear to logistic. Dive into practical deep learning with neural networks and support vector machines and unearth valuable insights from complex data sets with market basket analysis. Learn how to unlock hidden patterns within your data using k-means clustering. With three new chapters on data, you’ll hone your skills in advanced data preparation, mastering feature engineering, and tackling challenging data scenarios. This book helps you conquer high-dimensionality, sparsity, and imbalanced data with confidence. Navigate the complexities of big data with ease, harnessing the power of parallel computing and leveraging GPU resources for faster insights. Elevate your understanding of model performance evaluation, moving beyond accuracy metrics. With a new chapter on building better learners, you’ll pick up techniques that top teams use to improve model performance with ensemble methods and innovative model stacking and blending techniques. Machine Learning with R, Fourth Edition, equips you with the tools and knowledge to tackle even the most formidable data challenges. Unlock the full potential of machine learning and become a true master of the craft.
Table of Contents (18 chapters)
16
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17
Index

Handling missing data

The teaching datasets used for examples in previous chapters rarely had the problem of missing data, where a value that should be present is instead absent. The R language uses the special value NA to indicate these missing values, which cannot be handled natively by most machine learning functions. In Chapter 9, Finding Groups of Data – Clustering with k-means, we were able to replace missing values with a guess of the true value based on other information available in the dataset in a process called imputation. Specifically, the missing age values of high school students were imputed with the average age of students that had the same graduation year. This provided a reasonable estimate of the unknown age value.

Missing data is a much greater problem in real-world machine learning projects than would be expected given its rarity so far. This is not only because real-world projects are messier and more complex than simple textbook examples. Additionally...