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rforcats

What is the difference between fct_unique and unique?

What is the difference between the functions unique() and fct_unique()? There does not seem to be any difference other than fct_unique() only works with factors, whereas unique() works with all variables, categorical and numeric.

Solution

  • Apart from the difference already mention in the question that fct_unique only works with factors, other difference is the way they return the output. 

    f <- factor(c('a', 'x', 'b', 'b', 'y', 'r'))
f
#[1] a x b b y r
#Levels: a b r x y

forcats::fct_unique(f)
#[1] a b r x y
#Levels: a b r x y

unique(f)
#[1] a x b y r
#Levels: a b r x y

    fct_unique returns output in order of the factor levels whereas unique returns in the order of their occurrence in the vector.