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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Do not modify this file since it was automatically generated from:
%
% withSeed.R
%
% by the Rdoc compiler part of the R.oo package.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\name{withSeed}
\alias{withSeed}
\title{Evaluate an R expression with a temporarily set random set}
\description{
Evaluate an R expression with a temporarily set random set.
}
\usage{
withSeed(expr, seed, ..., substitute=TRUE, envir=parent.frame())
}
\arguments{
\item{expr}{The R expression to be evaluated.}
\item{seed, ...}{Arguments passed to \code{\link[base]{set.seed}}().}
\item{substitute}{If \code{\link[base:logical]{TRUE}}, argument \code{expr} is
\code{\link[base]{substitute}()}:ed, otherwise not.}
\item{envir}{The \code{\link[base]{environment}} in which the expression should be evaluated.}
}
\value{
Returns the results of the expression evaluated.
}
\details{
Upon exit (also on errors), this function will restore
\code{\link[base]{.Random.seed}} in the global environment to the value
it had upon entry. If it did not exist, it will be removed.
}
\author{Henrik Bengtsson}
\examples{
# Generate a random number
y0 <- runif(1)
print(y0)
# Generate a random number using the same seed over and over
yp <- NULL
for (ii in 1:10) {
y <- withSeed({
runif(1)
}, seed=0x42)
print(y)
# Assert identical
if (!is.null(yp)) stopifnot(identical(y, yp))
yp <- y
}
# Generate a random number
y <- runif(1)
print(y)
}
\seealso{
Internally, \code{\link[base]{set.seed}}() is used to set the random seed.
}
\keyword{IO}
\keyword{programming}
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