Here is one way to use rle() to solve the problem:
shortRunsOfOnesToNAs <- function(x, n) {
r <- rle(x)
r$values[r$values==1 & r$lengths < n] <- NA
rep(r$values, r$lengths)
}
E.g.,
input <- c(0,0,1,1,1,0,0,0,0,1,1,1,1,1,1,1,1)
result <- shortRunsOfOnesToNAs(input, 5)
desiredResult <- c(0,0,NA,NA,NA,0,0,0,0,1,1,1,1,1,1,1,1)
all.equal(desiredResult, result) # TRUE
Bill Dunlap
TIBCO Software
wdunlap tibco.com
On Thu, Jul 10, 2014 at 5:34 AM, jeff6868 <geoffrey_kl...@etu.u-bourgogne.fr
> wrote:
> Hi everybody,
>
> I have a small problem in a function, about removing short sequences of
> identical numeric values.
>
> For the example, we can consider this data, containing only some "0" and
> "1":
>
> test <- data.frame(x=c(0,0,1,1,1,0,0,0,0,1,1,1,1,1,1,1,1))
>
> The aim of my purpose here is simply to remove each sequence of "1" with a
> length shorter than 5, and to keep sequences of "1" which are bigger than
> 5.
> So my final data should look like this:
>
> final <- data.frame(x=c(0,0,NA,NA,NA,0,0,0,0,1,1,1,1,1,1,1,1))
>
> For the moment, I have this function:
>
> foo <- function(X,N){
> tab <- table(X[X==1])
> under.n <- as.numeric(names(tab)[tab<N])
> ind <- X %in% under.n
> Ind.sup <- which(ind)
> X <- ifelse(ind,NA,X)
> }
>
> test$x <- apply(as.data.frame(test$x),2,function(x) foo(x,5))
>
> The problem is that the function doesn't consider each sequence separately,
> but only one sequence. I think that adding rle() instead of table() in my
> function should to the trick, but it doesn't work yet.
> Does someone have an idea about fixing this problem?
>
>
>
>
>
> --
> View this message in context:
> http://r.789695.n4.nabble.com/find-remove-sequences-of-at-least-N-values-for-a-specific-value-tp4693810.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
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> PLEASE do read the posting guide
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>
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