Replacing tied rank by their average

Question

I have the following dataframe:

> x
  tags freq.Freq
1    a       740
2    b       722
3    c       722
4    d       541
5    e       525
6    f       525
7    g       525
8    h       326
9    i       296

i.e.

x<- structure(list(tags = c("a", "b", "c", "d", "e", "f", "g", "h", "i"),
 freq.Freq = c(740L, 722L, 722L, 541L, 525L, 525L, 525L, 326L, 296L)), 
class = "data.frame", row.names = c("1", "2", "3", "4", "5", "6", "7", "8", "9"))

I would like to replace the column freq.Freq by ranking of each letter in tags. E.g., a is 1, d is 4, i is 9. Anyway, b, c, and e, f, g have the same ranks. For these cases I would like to replace freq.Freq by the average of "tied" ranks. In this way the desired output is:

  tags freq.Freq
1    a       1
2    b       2.5
3    c       2.5
4    d       4
5    e       6
6    f       6
7    g       6
8    h       8
9    i       9

My attempt:

library(dplyr)
min_rank(x$freq.Freq)

gives a wrong result:

9 7 7 6 3 3 3 2 1

Answer 1

We can just use rank from base R. The default method for ties.method is "average"

x$freq.Freq <- rank(-x$freq.Freq)
x$freq.Freq
#[1] 1.0 2.5 2.5 4.0 6.0 6.0 6.0 8.0 9.0