Hello, I encountered a weird problem. Consider the following code that takes a list "lst" and shifts all elements one index up (for example, to make space for a new first element):
lst = list(1,2) ll = length(lst); for (i in ll:1) lst[[i+1]] = lst[[i]]; lst If you run it, you get the expected result [[1]] [1] 1 [[2]] [1] 1 [[3]] [1] 2 Now I change the input such that the first element is a NULL. lst = list(NULL,2) ll = length(lst); for (i in ll:1) lst[[i+1]] = lst[[i]]; lst When you run the code, you get [[1]] NULL [[2]] [1] 2 i.e. the shift did not happen. Why is that and how can the shift be made to work correctly in the presence of NULL elements in the list? Thanks, Peter ______________________________________________ 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.
