Changing repeated elements

[arnyeinstein]

Hi
I have data like this which has repeating numbers

c(1,1,1,4,6,1,1,1, 7,7,1,1,1,...) 

I would like to have this transformed to something like:

c(1,2,3,4,6,1,2,3,7,8, 1,2,3,...)

All the repeating numbers should be replaced by numbers that go up 1 at a time. Those that do not repeat remain the same.
Any ideas?
Cheers

Renger

[siddharthprabhu]

Good old for() loop to the rescue.

x <- c(1, 1, 1, 4, 6, 1, 1, 1, 7, 7, 1, 1, 1)

output_vec <- vector("numeric", length = length(x))

for (i in seq_along(x)) {
  if (i == 1) {
    output_vec[[i]] <- x[[i]]
  } else if (x[[i]] - x[[i - 1]] == 0) {
    output_vec[[i]] <- output_vec[[i - 1]] + 1
  } else {
    output_vec[[i]] <- x[[i]]
  }
}

print(output_vec)
#>  [1] 1 2 3 4 6 1 2 3 7 8 1 2 3

^{Created on 2020-10-19 by the reprex package (v0.3.0)}