Determine Duplicate Elements
Usage
duplicated(x)
Value
This function determines which elements of a vector are duplicates
of elements with smaller subscripts, and returns a
logical vector indicating which elements are duplicates.See Also
unique.Examples
x <- c(9:20, 1:5, 3:7, 0:8)
# extract unique elements
x[!duplicated(x)]
all(0:20 == sort(x[!duplicated(x)]))