Create sequence of repeated values, in sequence?

r repeat seq replicate
Wesley Burr picture Wesley Burr · Jun 21, 2011 · Viewed 127.5k times · Source

I need a sequence of repeated numbers, i.e. 1 1 ... 1 2 2 ... 2 3 3 ... 3 etc. The way I implemented this was:

  nyear <- 20
  names <- c(rep(1,nyear),rep(2,nyear),rep(3,nyear),rep(4,nyear),
             rep(5,nyear),rep(6,nyear),rep(7,nyear),rep(8,nyear))

which works, but is clumsy, and obviously doesn't scale well.

How do I repeat the N integers M times each in sequence?

  • I tried nesting seq() and rep() but that didn't quite do what I wanted.
  • I can obviously write a for-loop to do this, but there should be an intrinsic way to do this!

Answer

Dirk Eddelbuettel picture Dirk Eddelbuettel · Jun 21, 2011

You missed the each= argument to rep():

R> n <- 3
R> rep(1:5, each=n)
 [1] 1 1 1 2 2 2 3 3 3 4 4 4 5 5 5
R>

so your example can be done with a simple

R> rep(1:8, each=20)

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