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\title{Split list, apply function, and return results in an array.}
laply(.data, .fun = NULL, ..., .progress = "none",
.inform = FALSE, .drop = TRUE, .parallel = FALSE,
.paropts = NULL)
\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
\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
if results are atomic with same type and dimensionality,
a vector, matrix or array; otherwise, a list-array (a
list with dimensions)
For each element of a list, apply function then combine
results into an array.
\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.
This function splits lists by elements.
If there are no results, then this function will return a
vector of length 0 (\code{vector()}).
laply(baseball, is.factor)
# cf
ldply(baseball, is.factor)
laply(seq_len(10), identity)
laply(seq_len(10), rep, times = 4)
laply(seq_len(10), matrix, nrow = 2, ncol = 2)
Hadley Wickham (2011). The Split-Apply-Combine Strategy
for Data Analysis. Journal of Statistical Software,
40(1), 1-29. \url{}.
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}}
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