[R] jump in sequence
Ben Fairbank
BEN at SSANET.COM
Tue Jan 30 16:38:28 CET 2007
Or perhaps
rep(4:6,3)+9*rep(0:2,rep(3,3))
with changes as necessary for longer sequences
Ben Fairbank
-----Original Message-----
From: r-help-bounces at stat.math.ethz.ch
[mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Adrian DUSA
Sent: Tuesday, January 30, 2007 8:29 AM
To: r-help at stat.math.ethz.ch
Subject: [R] jump in sequence
Dear list,
This should be a simple one, I just cannot see it.
I need to generate a sequence of the form:
4 5 6 13 14 15 22 23 24
That is: starting with 4, make a 3 numbers sequence, jump 6, then
another 3
and so on.
I can create a whole vector with:
myvec <- rep(rep(c(F, T, F), rep(3, 3)), 3)
Then see which are TRUE:
which(myvec)
[1] 4 5 6 13 14 15 22 23 24
I'd like to avoid creating the whole vector if possible; for very large
ones
it can be time consuming. There should be a way to only create the
proper
indexes...
Thanks for any hint,
Adrian
--
Adrian Dusa
Romanian Social Data Archive
1, Schitu Magureanu Bd
050025 Bucharest sector 5
Romania
Tel./Fax: +40 21 3126618 \
+40 21 3120210 / int.101
______________________________________________
R-help at stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
More information about the R-help
mailing list