R: First Word in a String or Expression

first.word {Hmisc}

R Documentation

First Word in a String or Expression

Description

first.word finds the first word in an expression. A word is defined by unlisting the elements of the expression found by the S parser and then accepting any elements whose first character is either a letter or period. The principal intended use is for the automatic generation of temporary file names where it is important to exclude special characters from the file name. For Microsoft Windows, periods in names are deleted and only up to the first 8 characters of the word is returned.

Usage

first.word(x, i=1, expr=substitute(x))

Arguments

`x`	any scalar character string
`i`	word number, default value = 1. Used when the second or `i`th word is wanted. Currently only the `i=1` case is implemented.
`expr`	any S object of mode `expression`.

Value

a character string

Author(s)

Frank E. Harrell, Jr.,
Department of Biostatistics,
Vanderbilt University,
f.harrell@vanderbilt.edu

Richard M. Heiberger,
Department of Statistics,
Temple University, Philadelphia, PA.
rmh@astro.ocis.temple.edu

Examples

first.word(expr=expression(y ~ x + log(w)))

[Package Hmisc version 3.0-10 Index]