# vec_duplicate: Find duplicated values In vctrs: Vector Helpers

 vec_duplicate R Documentation

## 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

• `vec_proxy_equal()`

`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 documentation built on May 29, 2024, 11:39 a.m.