[R] keep only the first value of a numeric sequence

[Jorge I Velez]

Dear jeff6868,

Here is one way:

ifelse(with(data, c(0, diff(mydata))) != 1, 0, 1)

You could also take a look at ?rle

HTH,
Jorge.-



On Mon, Dec 15, 2014 at 9:33 PM, jeff6868 <geoffrey_klein at etu.u-bourgogne.fr
> wrote:
>
> Hello dear R-helpers,
>
> I have a small problem in my algorithm. I have sequences of "0" and "1"
> values in a column of a huge data frame, and I just would like to keep the
> first value of each sequences of "1" values, such like in this example:
>
> data <-
>
> data.frame(mydata=c(0,0,0,1,1,1,1,1,0,0,0,0,1,1,1,0,0,0,0,1,1,1,1,1,1,1),final_wished_data=c(0,0,0,1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,1,0,0,0,0,0,0))
>
> Any easy way to do this?
>
> Thanks everybody!
>
>
>
>
> --
> View this message in context:
> http://r.789695.n4.nabble.com/keep-only-the-first-value-of-a-numeric-sequence-tp4700774.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
>

	[[alternative HTML version deleted]]