This should do it for you:
> x <- c( TRUE, TRUE, TRUE, FALSE, FALSE, TRUE, TRUE, FALSE, TRUE );
> y <- rle(x)
> unlist(lapply(seq(length(y$lengths)), function(.indx){
+ if (y$values[.indx]) seq(y$lengths[.indx])
+ else rep(0, y$lengths[.indx])
+ }))
[1] 1 2 3 0 0 1 2 0 1
On 6/19/07, Feng, Ken <[EMAIL PROTECTED]> wrote:
>
> Hi,
>
> I start with an array of booleans:
>
> x <- c( TRUE, TRUE, TRUE, FALSE, FALSE, TRUE, TRUE, FALSE, TRUE );
>
> I want to define an y <- f(x) such that:
>
> y <- c( 1, 2, 3, 0, 0, 1, 2, 0, 1 );
>
> In other words, do a cumsum when I see a TRUE, but reset to 0 if I see a
> FALSE.
>
> I know I can do this with a very slow and ugly loop or maybe use apply,
> but I was hoping there are some R experts out there who can show me
> a cleaner/more elegant solution?
>
> Thanks in advance.
>
> - Ken
>
> ______________________________________________
> [email protected] 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.
>
--
Jim Holtman
Cincinnati, OH
+1 513 646 9390
What is the problem you are trying to solve?
[[alternative HTML version deleted]]
______________________________________________
[email protected] 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.
