The most efficient way to calculate numbero of unique values in vector

Question

Is there better way to compute this instead of:

length(unique(vector))

let's assume that we donno what class is the vector.

@Cath, they are not asking to do this by group as far as I can see — talat, Mar 28 '17 at 09:28
@docendodiscimus indeed but you can consider you have only one group and considering the target Q and the answers, I found it close enough (but looking for Q&A to add to the target) — Cath, Mar 28 '17 at 09:30

score 0 · Answer 1 · answered Mar 28 '17 at 09:21

0

You can use

library(data.table)
vector <- c(1,2,2,2,3)
uniqueN(vector)

answered Mar 28 '17 at 09:21

67342343

I have found uniqueN to be 3 times slower: data(iris) x – wBacz Mar 28 '17 at 09:56

1 Answers1