grouped_dt {dtplyr} | R Documentation |
The easiest way to create a grouped data table is to call the group_by
method on a data table or tbl: this will take care of capturing
the unevalated expressions for you.
grouped_dt(data, vars, copy = TRUE) is.grouped_dt(x)
data |
a tbl or data frame. |
vars |
a list of quoted variables. |
copy |
If |
x |
an object to check |
library(dplyr, warn.conflicts = FALSE) if (require("nycflights13")) { flights_dt <- tbl_dt(flights) group_size(group_by(flights_dt, year, month, day)) group_size(group_by(flights_dt, dest)) monthly <- group_by(flights_dt, month) summarise(monthly, n = n(), delay = mean(arr_delay)) }