Create a ranking variable with dplyr?

Question

Suppose I have the following data

df = data.frame(name=c("A", "B", "C", "D"), score = c(10, 10, 9, 8)) 

I want to add a new column with the ranking. This is what I'm doing:

df %>% mutate(ranking = rank(score, ties.method = 'first')) #   name score ranking # 1    A    10       3 # 2    B    10       4 # 3    C     9       2 # 4    D     8       1 

However, my desired result is:

#   name score ranking # 1    A    10       1 # 2    B    10       1 # 3    C     9       2 # 4    D     8       3 

Clearly rank does not do what I have in mind. What function should I be using?

Answer 1

It sounds like you're looking for dense_rank from "dplyr" -- but applied in a reverse order than what rank normally does.

Try this:

df %>% mutate(rank = dense_rank(desc(score))) #   name score rank # 1    A    10    1 # 2    B    10    1 # 3    C     9    2 # 4    D     8    3 

Answer 2

Other solution when you need to apply the rank to all variables (not just one).

df = data.frame(name = c("A","B","C","D"),                 score=c(10,10,9,8), score2 = c(5,1,9,2))  select(df, -name) %>% mutate_all(funs(dense_rank(desc(.))))