alply {plyr} | R Documentation |
For each slice of an array, apply function then combine results into a list
alply(.data, .margins, .fun = NULL, ..., .progress = "none")
.data |
matrix, array or data frame to be processed |
.margins |
a vector giving the subscripts to split up data by. 1 splits up by rows, 2 by columns and c(1,2) by rows and columns, and so on for higher dimensions |
.fun |
function to apply to each piece |
... |
other arguments passed on to .fun |
.progress |
name of the progress bar to use, see create_progress_bar |
All plyr functions use the same split-apply-combine strategy: they split the
input into simpler pieces, apply .fun
to each piece, and then combine
the pieces into a single data structure. This function splits matrices,
arrays and data frames by dimensions and combines the result into a list.
If there are no results, then this function will return a list of length 0
(list()
).
alply
is somewhat similar to apply
for cases where the
results are not atomic.
@keyword manip
@arguments matrix, array or data frame to be processed
@arguments a vector giving the subscripts to split up data
by. 1 splits up by rows, 2 by columns and c(1,2) by rows and columns, and so on for higher dimensions
@arguments function to apply to each piece
@arguments other arguments passed on to .fun
@arguments name of the progress bar to use, see create_progress_bar
@value list of results
list of results
Hadley Wickham <h.wickham@gmail.com>
alply(ozone, 3, quantile) alply(ozone, 3, function(x) table(round(x)))