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.