[R] Sequence detection longer than a certain value

[Rui Barradas]

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]]
>
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