Creating variable based on how many times a value is duplicated in R-CodePudding

I'm trying a build a variable (Three_CM2) based on the variable CODE_UAI such that if a value in CODE_UAI is duplicated 3 times then 'Three_CM2' equals 3. So far, I've come up with this which does not work. I feel like I'm on the right track but need the extra push.

Thanks!

Ech_final_nom_BSA %>%
  mutate(Three_CM2 = case_when(count(CODE_UAI) == 3 ~ 1, T ~ 0))

CodePudding user response：

Does this work:

library(dplyr)

Ech_final_nom_BSA  <- data.frame(CODE_UAI = c(1,1,1,2,3,4,4,4))
Ech_final_nom_BSA
  CODE_UAI
1        1
2        1
3        1
4        2
5        3
6        4
7        4
8        4
Ech_final_nom_BSA %>% group_by(CODE_UAI) %>% mutate(Three_CM2 = case_when(n() == 3 ~ 1, T ~ 0))
# A tibble: 8 x 2
# Groups:   CODE_UAI [4]
  CODE_UAI Three_CM2
     <dbl>     <dbl>
1        1         1
2        1         1
3        1         1
4        2         0
5        3         0
6        4         1
7        4         1
8        4         1

CodePudding user response：

Using base R

Ech_final_nom_BSA$Three_CM2 <- with(Ech_final_nom_BSA,  (ave(CODE_UAI, CODE_UAI, FUN = length) == 3))