R quantile by groups with assignments
问题 I have the following df: group = rep(seq(1,3),30) variable = runif(90, 5.0, 7.5) df = data.frame(group,variable) I need to i) Define quantile by groups, ii) Assign each person to her quantile with respect to her group. Thus, the output would look like: id group variable quantile_with_respect_to_the_group 1 1 6.430002 1 2 2 6.198008 3 ....... There is a complicated way to do it with loops and cut function over each groups but it is not efficient at all. Does someone know a better solution ?