Get the unique value in x or NA if none

Source: R/merge_samples.R

If unique(x) is a single value, return it; otherwise, return an NA of the same type as x. If x is a factor, then the levels and ordered status will be kept in either case. If x is a non-atomic vector (i.e. a list), then the logical NA will be used.

unique_or_na(x)

Arguments

x

A vector

Examples

f <- factor(c("a", "a", "b", "c"), ordered = TRUE)
unique_or_na(f)

#> Error in unique_or_na(f): could not find function "unique_or_na"
unique_or_na(f[1:2])

#> Error in unique_or_na(f[1:2]): could not find function "unique_or_na"

x <- c("a", "b", "a")
unique_or_na(x[c(1, 3)])

#> Error in unique_or_na(x[c(1, 3)]): could not find function "unique_or_na"
unique_or_na(x)

#> Error in unique_or_na(x): could not find function "unique_or_na"
unique_or_na(x) %>% typeof

#> Error in unique_or_na(x): could not find function "unique_or_na"