Remove all copies of rows with duplicate values in R [duplicate]

Answer 1

The dplyr package does this with intuitive, readable code.

Here's a toy example, taking rows from mtcars where there are no duplicated values of cyl and gear:

library(dplyr)
mtcars %>%
  group_by(cyl, gear) %>%
  filter(n() == 1) %>%
  ungroup()

Source: local data frame [2 x 11]

    mpg   cyl  disp    hp  drat    wt  qsec    vs    am  gear  carb
  (dbl) (dbl) (dbl) (dbl) (dbl) (dbl) (dbl) (dbl) (dbl) (dbl) (dbl)
1  21.5     4 120.1    97  3.70 2.465 20.01     1     0     3     1
2  19.7     6 145.0   175  3.62 2.770 15.50     0     1     5     6

Those two combinations of cyl and gear are the only unique ones, which you can confirm with:

mtcars %>%
  count(cyl, gear)