plyr (version 1.5.2)

d_ply: Split data frame, apply function, and discard results.

Description

Split data frame, apply function, and discard results. For each subset of a data frame, apply function and discard results

Usage

d_ply(.data, .variables, .fun, ..., .progress="none",
    .print=FALSE)

Arguments

.data

data frame to be processed

.variables

variables to split data frame by, as quoted variables, a formula or character vector

.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

.print

automatically print each result? (default: FALSE)

Details

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 data frames by variable and discards the output. This is useful for functions that you are calling purely for their side effects like display plots and saving output.

References

Hadley Wickham (2011). The Split-Apply-Combine Strategy for Data Analysis. Journal of Statistical Software, 40(1), 1-29. http://www.jstatsoft.org/v40/i01/.