Order of occurance of the same value in a vector

Question

I have the following series of numbers:

    id = c(1, 2, 1, 2, 4, 1, 1)

What is the most straightforward way to devise a vector including the order of each occurrence of each distinct number?

orders = c(1, 1, 2, 2, 1, 3, 4)

Answer 1

You could try

ave(id, id, FUN=seq_along)

Or

library(splitstackshape)
getanID(id)$.id