[R] obtaining null components of a list

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

Re: [R] obtaining null components of a list

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