Hadley Wickham - Advanced R, Second Edition

Second Edition

Series Editors

John M. Chambers, Department of Statistics, Stanford University, California, USA

Torsten Hothorn, Division of Biostatistics, University of Zurich, Switzerland

Duncan Temple Lang, Department of Statistics, University of California, Davis, USA

Hadley Wickham, RStudio, Boston, Massachusetts, USA

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Advanced R, Second Edition

Hadley Wickham

For more information about this series, please visit: https://www.crcpress.com/go/the-r-series

Second Edition

Hadley Wickham

CRC Press

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Welcome to the second edition of Advanced R. I had three main goals for this edition:

• Improve coverage of important concepts that I fully understood only after the publication of the first edition.

• Reduce coverage of topics time has shown to be less useful, or that I think are really exciting but turn out not to be that practical.

• Generally make the material easier to understand with better text, clearer code, and many more diagrams.

If youre familiar with the first edition, this preface describes the major changes so that you can focus your reading on the new areas. If youre reading a printed version of this book youll notice one big change very quickly: Advanced R is now in colour! This has considerably improved the syntax highlighting of code chunks, and made it much easier to create helpful diagrams. I have taken advantage of this and included over 100 new diagrams throughout the book.

Another big change in this version is the use of new packages, particularly rlang (http://rlang.r-lib.org), which provides a clean interface to low-level data structures and operations. The first edition used base R functions almost exclusively, which created some pedagogical challenges because many functions evolved independently over multiple years, making it hard to see the big underlying ideas hidden amongst the incidental variations in function names and arguments. I continue to show base equivalents in sidebars, footnotes, and where needed, in individual sections, but if you want to see the purest base R expression of the ideas in this book, I recommend reading the first edition, which you can find online at http://adv-r.had.co.nz.

The foundations of R have not changed in the five years since the first edition, but my understanding of them certainly has. Thus, the overall structure of Foundations has remained roughly the same, but many of the individual chapters have been considerably improved:

• , Names and values, is a brand new chapter that helps you understand the difference between objects and names of objects. This helps you more accurately predict when R will make a copy of a data structure, and lays important groundwork to understand functional programming.