rowwise {dplyr} | R Documentation |
rowwise
is used for the results of do
when you
create list-variables. It is also useful to support arbitrary
complex operations that need to be applied to each row.
rowwise(data)
data |
Input data frame. |
Currently rowwise
grouping only works with data frames. Its
main impact is to allow you to work with list-variables in
summarise
and mutate
without having to
use [[1]]
. This makes summarise()
on a rowwise tbl
effectively equivalent to plyr's ldply
.
df <- expand.grid(x = 1:3, y = 3:1) df %>% rowwise() %>% do(i = seq(.$x, .$y)) .Last.value %>% summarise(n = length(i))