Show rows that appear only once in R dataframe-CodePudding

I know that we can use unique() to effectively show a dataframe without duplicate values, but is there an elegant way to show only those rows that appear once in a dataframe?

E.g.,

a = c(10,20,10,10)
b = c(10,30,10,20)
ab = data.frame(a,b)

should return the second and final row only, and not the first and third (since this row exists more than once).

Thanks

CodePudding user response：

We can use duplicated

subset(ab, !(duplicated(ab)|duplicated(ab, fromLast = TRUE)))

-output

   a  b
2 20 30
4 10 20

CodePudding user response：

dplyr option:

library(dplyr)
ab %>%
  group_by(across(everything())) %>%
  filter(n() == 1)

Output:

# A tibble: 2 × 2
# Groups:   a, b [2]
      a     b
  <dbl> <dbl>
1    20    30
2    10    20