11

STRING MANIPULATION

Although R is a statistical language with

numeric vectors and matrices playing a

central role, character strings are surpris-

ingly important as well. Ranging from birth

dates stored in medical research data files to text-

mining applications, character data arises quite fre-

quently in R programs. Accordingly, R has a number

of string-manipulation utilities, many of which will be

introduced in this chapter.

11.1 An Overview of String-Manipulation Functions.................................

Here, we’ll briefly review just some of the many string-manipulation func-

tions R has to offer. Note that the call forms shown in this introduction

are very simple, usually omitting many optional arguments. We’ll use some

of those arguments in our extended examples later in the chapter, but do

check R’s online help for further details.