Hello, I have 2 variable: one is an "id" sequence from 1:1000 and the other is variable with real values "VI" from -15.0 to 20.0 and I want to detect id values that have indicator values less than a certain threshold, for example (x=1) BUT that are in sequence equal or longer than 5. For instance, in the following column I want to recognize the sequence from "id" 4 to 8 that are values with a "VI" values lower than 1 in a sequence of 5, and not the id values 1 and 2 which are values with VI lower than my threshold but the sequence is lower than 5. id VI 1 -10 2 -4 3 5 4 -2 5 -5 6 -3 7 -2 8 -1 9 4 10 8 Any help would be appreciated! Inti [[alternative HTML version deleted]]
z <- rle(VI<1) gets you most of the way there. ?rle will tell you what z is so that you can then use it to go the rest of the way. -- Bert On Tue, Aug 21, 2012 at 10:54 AM, inti luna <ilunalist at gmail.com> wrote:> Hello, > > I have 2 variable: one is an "id" sequence from 1:1000 and the other is > variable with real values "VI" from -15.0 to 20.0 and I want to detect id > values that have indicator values less than a certain threshold, for > example (x=1) BUT that are in sequence equal or longer than 5. > > For instance, in the following column I want to recognize the sequence from > "id" 4 to 8 that are values with a "VI" values lower than 1 in a sequence > of 5, and not the id values 1 and 2 which are values with VI lower than my > threshold but the sequence is lower than 5. > > id VI > > 1 -10 > 2 -4 > 3 5 > 4 -2 > 5 -5 > 6 -3 > 7 -2 > 8 -1 > 9 4 > 10 8 > > Any help would be appreciated! > > Inti > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at r-project.org 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.-- Bert Gunter Genentech Nonclinical Biostatistics Internal Contact Info: Phone: 467-7374 Website: http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm
Hello,
Try the following
d <- read.table(text="
id VI
1 -10
2 -4
3 5
4 -2
5 -5
6 -3
7 -2
8 -1
9 4
10 8
", header = TRUE)
fun <- function(n, thres){
r <- rle(!d$VI < thres)
inx <- which(!r$values & r$lengths >= n)
csum <- cumsum(r$lengths)
from <- ifelse(inx == 1, 1, csum[inx - 1] + 1)
cbind(from = from, to = csum[inx])
}
fun(5, 1)
fun(2, 1)
Hope this helps,
Rui Barradas
Em 21-08-2012 18:54, inti luna escreveu:> Hello,
>
> I have 2 variable: one is an "id" sequence from 1:1000 and the
other is
> variable with real values "VI" from -15.0 to 20.0 and I want to
detect id
> values that have indicator values less than a certain threshold, for
> example (x=1) BUT that are in sequence equal or longer than 5.
>
> For instance, in the following column I want to recognize the sequence from
> "id" 4 to 8 that are values with a "VI" values lower
than 1 in a sequence
> of 5, and not the id values 1 and 2 which are values with VI lower than my
> threshold but the sequence is lower than 5.
>
> id VI
>
> 1 -10
> 2 -4
> 3 5
> 4 -2
> 5 -5
> 6 -3
> 7 -2
> 8 -1
> 9 4
> 10 8
>
> Any help would be appreciated!
>
> Inti
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org 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.