Package that includes functions for data manipulation. It is suggested to use the package with data.table.
You can install the package using devtools:
devtools::install_github("santiagohermo/data.tools")library(data.tools)
# Simulate panel data
dt <- data.table::data.table(unit = c("A", "A", "B", "B", "C", "C", "D", "D", "E", "E"),
time = rep(c(1, 2), 5))
dt[, y := rnorm(.N)]
# Create equal-sized groups
dt[, terciles_y := cut_in_n(y, n=3)]
dt[, terciles_y_within := cut_in_n(y, n=3), by=time]
# Save the data set
save_data(dt, key = c("unit", "time"),
outfile = "data.csv")