gdata (version 2.18.0.1)

duplicated2: Determine Duplicate Elements

Description

duplicated2() determines which elements of a vector or data frame are duplicates, and returns a logical vector indicating which elements (rows) are duplicates.

Usage

duplicated2(x, bothWays=TRUE, ...)

Value

For a vector input, a logical vector of the same length as

x. For a data frame, a logical vector with one element for each row. For a matrix or array, and when MARGIN = 0, a logical array with the same dimensions and dimnames.

For more details see duplicated.

Arguments

x

a vector or a data frame or an array or NULL.

bothWays

if TRUE (the default), duplication should be considered from both sides. For more information see the argument fromLast to the function duplicated.

...

further arguments passed down to duplicated() and its methods.

Author

Liviu Andronic

Details

The standard duplicated function (in package:base) only returns TRUE for the second and following copies of each duplicated value (second-to-last and earlier when fromLast=TRUE). This function returns all duplicated elementes, including the first (last) value.

When bothWays is FALSE, duplicated2() defaults to a duplicated call. When bothWays is TRUE, the following call is being executed: duplicated(x, ...) | duplicated(x, fromLast=TRUE, ...)

See Also

duplicated, unique

Examples

  data(iris)
  iris[duplicated(iris), ]                 # 2nd duplicated value
  iris[duplicated(iris, fromLast=TRUE), ]  # 1st duplicated value
  iris[duplicated2(iris), ]                # both duplicated values