Introduction to R

An Introduction to R

Notes on R: A Programming Environment for Data Analysis and Graphics

Version 3.1.1 (2014-07-10)

W. N. Venables, D. M. Smith

and the R Core Team

This manual

Copyright c

Copyright c

Copyright c

Copyright c

Copyright c

is for R, version 3.1.1 (2014-07-10).

1990 W. N. Venables

1992 W. N. Venables & D. M. Smith

1997 R. Gentleman & R. Ihaka

1997, 1998 M. Maechler

1999–2013 R Core Team

Permission is granted to make and distribute verbatim copies of this manual provided

the copyright notice and this permission notice are preserved on all copies.

Permission is granted to copy and distribute modified versions of this manual under

the conditions for verbatim copying, provided that the entire resulting derived work

is distributed under the terms of a permission notice identical to this one.

Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that this

permission notice may be stated in a translation approved by the R Core Team.

i

Table of Contents

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1

Introduction and preliminaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.1

1.2

1.3

1.4

1.5

1.6

1.7

1.8

1.9

1.10

1.11

2

Intrinsic attributes: mode and length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Changing the length of an object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Getting and setting attributes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

The class of an object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

13

14

14

14

Ordered and unordered factors. ....