Try this: r <- unlist(sapply(x, function(x) c(rep(0, x), 1))) x2 <- diff(c(0, which(r==1))) - 1 identical(x, x2)
On Sun, Mar 9, 2008 at 7:55 PM, remko duursma <[EMAIL PROTECTED]> wrote: > > Dear R-helpers, > > I have two problems that I don't know how to vectorize (but would like to > because my current solution is slow). > > # 1. > #I have a vector x: > > x <- c(3, 0, 1, 0, 2, 2, 2, 0, 4, 2) > > #I want this translated into a new vector based on x,so that each element of x > #is the number of zeroes, followed by a 1. The new vector would look like: > > #> r# [1] 0 0 0 1 1 0 1 1 0 0 1 0 0 1 0 0 1 1 0 0 0 0 1 0 0 1 > > # I only found a solution that loops, and it's a bit ugly: > r <- c()for(i in 1:length(x))r <- c(r, rep(0,pmax(0,x[i])),1) > > > # 2. > # The other way around, so that we have the vector r, and want to find x. > # I have a (very) ugly solution: > chars <- paste(r,collapse="")zeros <- strsplit(chars,"1")x <- > nchar(zeros[[1]]) > > > > Thanks for your help! > > Remko Duursma > [[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.
