set.seed(5)
testdata = tibble(x=sample(c("a","b","c"),size=1000,replace=T),
y=rnorm(1000),
z=rnorm(1000))
testdata %>% group_by(x) %>% dim
Can anyone explain why the output of the last code is the dimension of the whole testdata
, not the dimensions of each of the three groups of it?