The New S Language : a programming environment for data analysis and graphics

721 Pages·2018·124.433 MB·

by  Becker, Richard A., Chambers, John M., Wilks, Allan R

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The" S Language
A PROGRAMMING ENVIRONMENT
FOR DATA ANALYSIS AND GRAPHICS

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The SL anguage
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A PROGRAMMING ENVIRONMENT
FOR DATA ANALYSIS AND GRAPHICS
Richard A. Becker
John M. Chambers
Allan R. Wilks
AT&T Bell Laboratories
CHAPMAN & HALL/CRC
Boca Raton London New York
CRC Press is an imprint of the
Boca Raton LTaoylnord &o Fnra ncNis eGwro uYp,o arnk in foWrmaa sbhuisinnegstson, D.C.
First published 1988 by CRC Press
Taylor & Francis Group
6000 Broken Sound Parkway NW, Suite 300
Boca Raton, FL 33487-2742
Reissued 2018 by CRC Press
© 1988 by Bell Telephone Laboratories Ind.
CRC Press is an imprint of Taylor & Francis Group, an Informa business
No claim to original U.S. Government works
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Library of Congress Cataloging-in-Publication Data
Becker, Richard A
The new S language
Bibliography: p.
Includes index.
ISBN 0-412-74150-4
1. S (Computer program language). I. Chambers, John M.
II. Wilks, Allan Reeve. III. Title.
QA76.73.S15B43 1988
519.5’028’55133—dc20 88-5656
A Library of Congress record exists under LC control number: 88005656
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The publisher has gone to great lengths to ensure the quality of this reprint but points out that some imperfections in
the original copies may be apparent.
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The publisher has made every effort to trace copyright holders and welcomes correspondence from those they have
been unable to contact.
ISBN 13: 978-1-315-89588-8 (hbk)
ISBN 13: 978-1-351-07498-8 (ebk)
Visit the Taylor & Francis Web site at http://www.taylorandfrancis.com and the
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To Eloise, Bea, and Fiona

Preface
S is a language and an interactive programming environment for data analysis
and graphics. The S language is a very high-level language for specifying
computations. The language is part of an interactive environment: S
encourages you to compute, look at data, and program interactively, with quick
feedback to enable you to learn and understand.
The primary goal of the S environment is to enable and encourage
good data analysis. The facilities in S are directed toward this goal.
• S is about data: it provides general and easy-to-use facilities for organ
izing, storing, and retrieving all sorts of data.
• S is about analysis: that is, computations you need to understand and
use data. S provides numerical methods and other computational tech
niques.
• S is about programming: you can write functions in the S language
itself. These functions can build on the power and simplicity of the S
language. Because S is highly interactive, new functions can be
designed and tried out much faster than with most languages. S also
provides simple interfaces to other kinds of computing, such as to com
mands from the UNIX system or to C or Fortran routines.
• Especially, S is about graphics: interactive, informative, flexible ways
of looking at data. The graphics capabilities of S are designed to
encourage you to create new tools and try out new ideas.
A wide range of people are presently using S in diverse areas-financial
analysis, statistics research, management, academia-for analytical computing,
graphics, and data analysis. Join them and learn the power of working with S.
vii
viii Preface
How to Read This Book
This book describes the S language and environment. When you read it, we
recommend combining reading with doing. Have a computer terminal handy,
preferably with graphics, and start S running. Read a little, then try out some
of the examples or exercises, and experiment with variations or with your own
data. A good way to review or supplement the discussion of a particular S
function, say plot, is to look at the on-line documentation by typing
> help(plot)
In particular, whenever the book suggests looking up something in Appendix 1,
you can use the on-line documentation instead.
We have tried to organize the book to facilitate self-teaching. Most
chapters contain exercises that review and sometimes extend the material.
Answers to many of the exercises appear at the end of the chapter.
As you read through the book, you may notice a gradual transition.
Early chapters focus on using S informally for your own analysis. Later on,
the emphasis shifts to more ambitious use of S as a programming environment
for applications. This shift reflects the experience of many S users, who find
that S leads them gently into the world of software design.
The book begins with three introductory chapters that should be helpful
to all users: a case study that shows S without trying to explain it; a tutorial
chapter covering material in an informal way; and a more formal treatment of
the basic techniques in the language. You should be able to get through this
material with a few hours of work. At this point, you will be able to use S
productively.
The next three chapters introduce many more capabilities and help you
understand the philosophy behind S. Chapter 4 gives an introduction to graph
ics within S, ranging from high-level plotting commands to detailed control of
plots. The emphasis is on analytical displays: those that are valuable during
data analysis. Chapter 5 describes data in S, explaining how S organizes
matrices, arrays, and other kinds of data and introducing techniques to help you
organize data for your applications. Chapter 6 discusses how to write S func
tions, including editing, debugging, and using the interface to the UNIX system.
When you have finished the first six chapters, you should be able to create new
facilities in S and use it creatively in your data analysis.
Chapters 7 and 8 provide advanced material that will be of interest if
you intend to develop applications within S that will be used by others. Func
tion writing is the topic of chapter 7; it introduces the interface to C and For
tran plus powerful techniques for controlling how S works and for symbolic
computation. Chapter 8 ties together the organization of data with the design
of functions; the combination of these ideas will often be the key to effective
use of S in your own major applications.
Preface ix
Chapter 9 is for everyone. It brings together ideas from other chapters
in the book, providing case studies and examples of using S for a variety of
tasks, from data organization to solving numerical problems to a computer
game. It also discusses matters of style and strategy in the use of S. It is a
repository for important concepts, general ways of attacking problems, and
advice on how best to use S. Advanced graphics material follows in chapter
10, which shows how to use the capabilities of S to implement new graphics
functions. Chapter 11 gives a compact description of the syntax and semantics
of the S language, and will be of most interest to those of you who want to
know how S really works. Finally, we end with an annotated bibliography list
ing some books that may be of interest to you as you use S.
The narrative material ends midway through the book. Most of the
remainder is devoted to detailed documentation of the S functions and datasets.
Documentation for S functions is presented in Appendix 1. Appendix 2
describes the datasets that are available in the system data directory. The mate
rial in Appendices 1 and 2 is also available on-line for the S user. Appendix 3
provides one-line descriptions of S functions, broken down by various topics.
It can help you to find functions when you can't remember their names.
Appendix 4 gives people who have used an earlier version of S a description of
what has changed. An extensive index at the end of the book can be used for
quick access to the places in the text where specific topics are discussed.
The Software
S is a software system that runs under the UNIX operating system on a variety
of hardware configurations. S is designed to take advantage of other tools and
languages provided by the operating system. As this book is being written, S
runs on many different computers, from supermicros to large mainframe
machines. Work is continually under way to implement S on new hardware.
For information on obtaining source code for S, contact:
AT&T Software Licensing Manager
Room 3A36
10 Independence Blvd.
Warren, NJ 07060-9824
[phone]
[phone] Fax
[phone] International
There are also a number of independent vendors selling binary-only versions of
S. The binary versions are adapted to specific computers and, sometimes, to
other operating systems. A list of the vendors is available from AT&T.