Become an expert in R — Interactive courses, Cheat Sheets, certificates and more!
Get Started for Free

vec_duplicate

Find duplicated values


Description

  • vec_duplicate_any(): detects the presence of duplicated values, similar to anyDuplicated().

  • vec_duplicate_detect(): returns a logical vector describing if each element of the vector is duplicated elsewhere. Unlike duplicated(), it reports all duplicated values, not just the second and subsequent repetitions.

  • vec_duplicate_id(): returns an integer vector giving the location of the first occurrence of the value.

Usage

vec_duplicate_any(x)

vec_duplicate_detect(x)

vec_duplicate_id(x)

Arguments

x

A vector (including a data frame).

Value

  • vec_duplicate_any(): a logical vector of length 1.

  • vec_duplicate_detect(): a logical vector the same length as x.

  • vec_duplicate_id(): an integer vector the same length as x.

Missing values

In most cases, missing values are not considered to be equal, i.e. NA == NA is not TRUE. This behaviour would be unappealing here, so these functions consider all NAs to be equal. (Similarly, all NaN are also considered to be equal.)

Dependencies

See Also

vec_unique() for functions that work with the dual of duplicated values: unique values.

Examples

vec_duplicate_any(1:10)
vec_duplicate_any(c(1, 1:10))

x <- c(10, 10, 20, 30, 30, 40)
vec_duplicate_detect(x)
# Note that `duplicated()` doesn't consider the first instance to
# be a duplicate
duplicated(x)

# Identify elements of a vector by the location of the first element that
# they're equal to:
vec_duplicate_id(x)
# Location of the unique values:
vec_unique_loc(x)
# Equivalent to `duplicated()`:
vec_duplicate_id(x) == seq_along(x)

vctrs

Vector Helpers

v0.3.8
MIT + file LICENSE
Authors
Hadley Wickham [aut], Lionel Henry [aut, cre], Davis Vaughan [aut], data.table team [cph] (Radix sort based on data.table's forder() and their contribution to R's order()), RStudio [cph]
Initial release

We don't support your browser anymore

Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.