R: preventing unlist to drop NULL values

Posted by nico on Stack Overflow See other posts from Stack Overflow or by nico
Published on 2010-06-07T17:01:54Z Indexed on 2010/06/07 17:42 UTC
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I'm running into a strange problem. I have a vector of lists and I use unlist on them. Some of the elements in the vectors are NULL and unlist seems to be dropping them. How can I prevent this?

Here's a simple (non) working example showing this unwanted feature of unlist

a = c(list("p1"=2, "p2"=5), 
      list("p1"=3, "p2"=4), 
      list("p1"=NULL, "p2"=NULL), 
      list("p1"=4, "p2"=5))
unlist(a)
 p1 p2 p1 p2 p1 p2 
 2  5  3  4  4  5

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R: preventing unlist to drop NULL values - Developer IT

R: preventing unlist to drop NULL values

list

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