vec_unique: Find and count unique values

In vctrs: Vector Helpers

Find and count unique values

Description

• vec_unique(): the unique values. Equivalent to unique().

• vec_unique_loc(): the locations of the unique values.

• vec_unique_count(): the number of unique values.

Usage

vec_unique(x)

vec_unique_loc(x)

vec_unique_count(x)

Arguments

x	A vector (including a data frame).

Value

• vec_unique(): a vector the same type as x containing only unique values.

• vec_unique_loc(): an integer vector, giving locations of unique values.

• vec_unique_count(): an integer vector of length 1, giving the number of unique values.

Dependencies

• vec_proxy_equal()

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.)

See Also

vec_duplicate for functions that work with the dual of unique values: duplicated values.

Examples

x <- rpois(100, 8)
vec_unique(x)
vec_unique_loc(x)
vec_unique_count(x)

# `vec_unique()` returns values in the order that encounters them
# use sort = "location" to match to the result of `vec_count()`
head(vec_unique(x))
head(vec_count(x, sort = "location"))

# Normally missing values are not considered to be equal
NA == NA

# But they are for the purposes of considering uniqueness
vec_unique(c(NA, NA, NA, NA, 1, 2, 1))

vctrs documentation built on Oct. 13, 2023, 1:05 a.m.