On Tue, May 08, 2012 at 02:50:47PM -0500, Jeff wrote: > > ...still new to R and trying to figure this one out. > > I have a number of variables x, y, z, etc. in a data frame. > > Each contains a 2 digit year (e.g., 80, 81, 82) representing the > first year that something occurred. Each variable represents a > different type of event. > > If the event did not occur at all, the variable has the value 0 (zero). > > I need to create a new variable having the value of the earliest year > among the set of variables. > > If none of the events occurred (all variables = 0), then the new > variable should also be zero. > > e.g., > > Original > x y z > 80 82 83 > 85 76 90 > 90 0 86 > 0 0 0 > > > New variable > 80 > 76 > 86 > 0
Hi. If all years are at most 99, then try the following dat <- data.frame(x=c(80, 85, 90, 0), y=c(82, 76, 0, 0), z=c(83, 90, 86, 0)) dat[dat == 0] <- Inf out <- pmin(dat$x, dat$y, dat$z) out[out == Inf] <- 0 out [1] 80 76 86 0 Hope this helps. Petr Savicky. ______________________________________________ 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.
