Try this: > x <- list(NULL, 1:10, 25, NULL, "more") > x [[1]] NULL
[[2]] [1] 1 2 3 4 5 6 7 8 9 10 [[3]] [1] 25 [[4]] NULL [[5]] [1] "more" > which(sapply(x, is.null)) [1] 1 4 > On Wed, Jan 21, 2009 at 7:42 AM, diego Diego <dhab...@gmail.com> wrote: > Hello everybody! > I have a list of length 5000 whose components are (mostly) "ts" objects, > but some these components are intentionally left empty, ie, they are "NULL" > components of the list. My question is how can I get the position of these > null components in a effective way (I'm trying to avoid a for-if rutine). > > > Thanks!!! > > [[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. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve? ______________________________________________ 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.