repeatable.Rd

\name{repeatable}
\alias{repeatable}
\title{Make a random number generator repeatable}
\usage{
  repeatable(rngfunc,
    seed = runif(1, 0, .Machine$integer.max))
}
\arguments{
  \item{rngfunc}{The function that is affected by the R
  session's seed.}

  \item{seed}{The seed to set every time the resulting
  function is called.}
}
\value{
  A repeatable version of the function that was passed in.
}
\description{
  Given a function that generates random data, returns a
  wrapped version of that function that always uses the
  same seed when called. The seed to use can be passed in
  explicitly if desired; otherwise, a random number is
  used.
}
\note{
  When called, the returned function attempts to preserve
  the R session's current seed by snapshotting and
  restoring \code{\link[base]{.Random.seed}}.
}
\examples{
rnormA <- repeatable(rnorm)
rnormB <- repeatable(rnorm)
rnormA(3)  # [1]  1.8285879 -0.7468041 -0.4639111
rnormA(3)  # [1]  1.8285879 -0.7468041 -0.4639111
rnormA(5)  # [1]  1.8285879 -0.7468041 -0.4639111 -1.6510126 -1.4686924
rnormB(5)  # [1] -0.7946034  0.2568374 -0.6567597  1.2451387 -0.8375699
}