search for: null_003f

Displaying 2 results from an estimated 2 matches for "null_003f".

2009 Dec 11
1
The correct way to set an element in a list to NULL? (FAQ is not clear)
http://cran.r-project.org/doc/FAQ/R-FAQ.html#How-can-I-set-components-of-a-list-to-NULL_003f The explanation on this FAQ entry is not clear. It says '... similarly for named components...'. What I understood was x[i]<-list(NULL) is the same as x$a_name<-list(NULL). But, they are not. As the example below shows, x$a_name<-list(NULL) is the same as x[[i]]<-list(NULL). &...
2009 Dec 11
1
How to get rid of NULL in the result of apply()?
The following code returns a list with the 2nd element as NULL. I'm wondering what the best way to get rid of NULL element in an 'apply()'s result. > lapply(1:3, function(x) { + if(x==2) { + return(NULL) + } else { + return(x) + } + } + ) [[1]] [1] 1 [[2]] NULL [[3]] [1] 3