On 25/10/15 12:33, Bert Gunter wrote:
Rolf's solution works for the situation where all duplicated values
are contiguous, which may be what you need. However, I wondered how it
could be done if this were not the case. Below is an answer. It is not
as efficient or elegant as Rolf's solution for the contiguous case I
think; maybe someone will come up with something better. But I think
it works. Here's an example with code:
w <- c(1:5,3,1,2,7,8,5,5,5,2,3)
w
[1] 1 2 3 4 5 3 1 2 7 8 5 5 5 2 3
d <- 0+duplicated(w)
for(x in unique(w)){
+ i <- w==x
+ d[i]<-1+ cumsum(d[i])
+
+ }
d
[1] 1 1 1 1 1 2 2 2 1 1 2 3 4 3 3
As always, corrections and/or improvements welcome.
How about:
o <- order(w)
d <- unlist(lapply(rle(w[o])$lengths,seq_len))[order(o)]
Works for the given example. :-)
cheers,
Rolf
--
Technical Editor ANZJS
Department of Statistics
University of Auckland
Phone: +64-9-373-7599 ext. 88276
On Sat, Oct 24, 2015 at 4:02 PM, Rolf Turner <r.tur...@auckland.ac.nz> wrote:
On 25/10/15 11:28, John Sorkin wrote:
I have a file that has (1) Line numbers, (2) IDs. A given ID number can
appear in more than one row. For each row with a repeated ID, I want to add
a number that gives the sequence number of the repeated ID number. The R
code below demonstrates what I want to have, without any attempt to produce
the result, as I have no idea how to accomplish my goal.
line <- c(1,2,3,4,5,6,7,8,9,10)
ID<- c(1,1,2,3,4,5,6,7,8,8)
cat("Note lines 1 and 2 both contain ID 1; lines 9 and 10 both contain ID
8")
cbind(line,ID)
Seq <- c(1,2,1,1,1,1,1,1,1,2)
cat("Sequence numbers within ID added to the data")
cbind(line,ID,Seq)
I *think* that
unlist(lapply(rle(ID)$lengths,seq_len))
gives what you want. At least it does for the given example.
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