Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Fetching contributors…

Cannot retrieve contributors at this time

85 lines (73 sloc) 2.551 kb
\name{laply}
\alias{laply}
\title{Split list, apply function, and return results in an array.}
\usage{
laply(.data, .fun = NULL, ..., .progress = "none",
.inform = FALSE, .drop = TRUE, .parallel = FALSE,
.paropts = NULL)
}
\arguments{
\item{.fun}{function to apply to each piece}
\item{...}{other arguments passed on to \code{.fun}}
\item{.progress}{name of the progress bar to use, see
\code{\link{create_progress_bar}}}
\item{.parallel}{if \code{TRUE}, apply function in
parallel, using parallel backend provided by foreach}
\item{.paropts}{a list of additional options passed into
the \code{\link[foreach]{foreach}} function when parallel
computation is enabled. This is important if (for
example) your code relies on external data or packages:
use the \code{.export} and \code{.packages} arguments to
supply them so that all cluster nodes have the correct
environment set up for computing.}
\item{.inform}{produce informative error messages? This
is turned off by by default because it substantially
slows processing speed, but is very useful for debugging}
\item{.data}{list to be processed}
\item{.drop}{should extra dimensions of length 1 in the
output be dropped, simplifying the output. Defaults to
\code{TRUE}}
}
\value{
if results are atomic with same type and dimensionality,
a vector, matrix or array; otherwise, a list-array (a
list with dimensions)
}
\description{
For each element of a list, apply function then combine
results into an array.
}
\details{
\code{laply} is similar in spirit to \code{\link{sapply}}
except that it will always return an array, and the
output is transposed with respect \code{sapply} - each
element of the list corresponds to a row, not a column.
}
\section{Input}{
This function splits lists by elements.
}
\section{Output}{
If there are no results, then this function will return a
vector of length 0 (\code{vector()}).
}
\examples{
laply(baseball, is.factor)
# cf
ldply(baseball, is.factor)
colwise(is.factor)(baseball)
laply(seq_len(10), identity)
laply(seq_len(10), rep, times = 4)
laply(seq_len(10), matrix, nrow = 2, ncol = 2)
}
\references{
Hadley Wickham (2011). The Split-Apply-Combine Strategy
for Data Analysis. Journal of Statistical Software,
40(1), 1-29. \url{http://www.jstatsoft.org/v40/i01/}.
}
\seealso{
Other array output: \code{\link{aaply}},
\code{\link{daply}}, \code{\link{maply}}
Other list input: \code{\link{l_ply}},
\code{\link{ldply}}, \code{\link{llply}}
}
\keyword{manip}
Jump to Line
Something went wrong with that request. Please try again.