Try this: > d <- diff(DF$time) > d[rep(c(FALSE, TRUE), length = length(d))] Time differences in secs [1] 0 0 0 10 1 6 23 2 1 > d[rep(c(TRUE, FALSE), length = length(d))] Time differences in secs [1] 6 1 4 6 0 2 4 8 1 0
On Fri, Jul 3, 2009 at 9:21 AM, <rory.wins...@gmail.com> wrote: > Hi > > I have a dataset that looks like this (dput'd below): > >> head(x, 20) > > time status > 1 2009-07-02 10:32:37 1 > 2 2009-07-02 10:32:43 0 > 3 2009-07-02 10:32:43 1 > 4 2009-07-02 10:32:44 0 > 5 2009-07-02 10:32:44 1 > 6 2009-07-02 10:32:48 0 > 7 2009-07-02 10:32:48 1 > 8 2009-07-02 10:32:54 0 > 9 2009-07-02 10:33:04 1 > 10 2009-07-02 10:33:04 0 > 11 2009-07-02 10:33:05 1 > 12 2009-07-02 10:33:07 0 > 13 2009-07-02 10:33:13 1 > 14 2009-07-02 10:33:17 0 > 15 2009-07-02 10:33:40 1 > 16 2009-07-02 10:33:48 0 > 17 2009-07-02 10:33:50 1 > 18 2009-07-02 10:33:51 0 > 19 2009-07-02 10:33:52 1 > 20 2009-07-02 10:33:52 0 > > I would like to be able to calculate the total time spent in state 0, in > other words > the diff of the times of x where x$status changes from 0 to 1. I've been > struggling > with tapply() to do this, but without huge success....anyone know an > elegant way > to do this? > > Cheers > -- Rory > > structure(list(time = structure(c(1246527157, 1246527163, 1246527163, > 1246527164, 1246527164, 1246527168, 1246527168, 1246527174, 1246527184, > 1246527184, 1246527185, 1246527187, 1246527193, 1246527197, 1246527220, > 1246527228, 1246527230, 1246527231, 1246527232, 1246527232), class = > c("POSIXt", > "POSIXct"), tzone = ""), status = c(1, 0, 1, 0, 1, 0, 1, 0, 1, > 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0)), .Names = c("time", "status" > ), row.names = c(NA, 20L), class = "data.frame") > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@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. > ______________________________________________ R-help@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.