do_by: split-apply-combine for vectors, with equal-length outptu
Description
Group x by one or more categorical variables, compute
an aggregate, repeat that aggregate to match the size of the
group, and combine results. The functions sum_by and
so on are convenience wrappers that call do_by internally.
Usage
do_by(x, by, fun, ...)
sum_by(x, by, na.rm = FALSE)
mean_by(x, by, na.rm = FALSE)
min_by(x, by, na.rm = FALSE)
max_by(x, by, na.rm = FALSE)
Arguments
x
A bare variable name
by
a bare variable name, or a list of bare variable names, used to
split x into groups.
fun
[function] A function that aggregates x to a single value.