isR.Rd 1.05 KB
 Radford Neal committed May 18, 2013 1 2 % File src/library/base/man/isR.Rd % Part of the R package, http://www.R-project.org  Radford Neal committed Aug 26, 2016 3 % Copyright 1995-2007 R Core Team  Radford Neal committed May 18, 2013 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 % Distributed under GPL 2 or later \name{is.R} \title{Are we using R, rather than S?} \usage{ is.R() } \alias{is.R} \description{ Test if running under \R. } \details{ The function has been written such as to correctly run in all versions of \R, S and S-PLUS. In order for code to be runnable in both \R and S dialects previous to S-PLUS 8.0, your code must either define \code{is.R} or use it as \code{if (exists("is.R") && is.function(is.R) && is.R()) \{}\cr \code{ }\emph{## R-specific code}\cr \code{\} else \{}\cr \code{ }\emph{## S-version of code}\cr \code{\}} } \value{ \code{is.R} returns \code{TRUE} if we are using \R and \code{FALSE} otherwise. } \seealso{\code{\link{R.version}}, \code{\link{system}}.} \examples{ x <- stats::runif(20); small <- x < 0.4 ## In the early years of R, 'which()' only existed in R: if(is.R()) which(small) else seq(along=small)[small] } \keyword{environment} \keyword{utilities}