How to get the top n elements (in terms of frequency) from a vector in R?

user_489010 0
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How can I get the top n ranking of an array in R?

lets say I have

a <- c(67, 2, 100, 2, 100, 23, 2, 100, 67, 89,100)

how can I get:

rank   number   times
1     100       4
2     2         3
3     67        2
4     23        1
4     89        1
r
6 Answers

A dplyr solution to this could be: 

library(dplyr)
df <- tibble(a = c(67, 2, 100, 2, 100, 23, 2, 100, 67, 89,100))
df %>% 
  count(a) %>% 
  mutate(rank = min_rank(-n)) %>%
  arrange(desc(n)) %>% 
  rename(number = a, times = n)
#> # A tibble: 5 x 3
#>   number times  rank
#>    <dbl> <int> <int>
#> 1    100     4     1
#> 2      2     3     2
#> 3     67     2     3
#> 4     23     1     4
#> 5     89     1     4
user_84751450

you can use df[df>0] <- 1, later rowSums(df), and finally with(df, df[order(-x, y, z), ] where -x is the column of frequency data and the others are I.D columns, and the suplementary information that you have.

user_87237590
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