clinpubr (version 1.1.1)

indicate_duplicates: Determine duplicate elements including their first occurrence.

Description

If an element is duplicated, all of its occurrence will be labeled TRUE. Useful to list and compare all duplicates.

Usage

indicate_duplicates(x)

Value

A logical vector.

Arguments

x

A vector.

Examples

indicate_duplicates(c(1, 2, NA, NA, 1))
indicate_duplicates(c(1, 2, 3, 4, 4))

# Useful to check duplicates in data frames.
df <- data.frame(
  id = c(1, 2, 1, 2, 3), year = c(2010, 2011, 2010, 2010, 2011),
  value = c(1, 2, 3, 4, 5)
)
df[indicate_duplicates(df[, c("id", "year")]), ]