is.null(mylist[1]) and is.null(mylist$a) returns different values
Hi, Try
is.null(mylist[[1]])
[1] TRUE Notice the double square brackets. From: ?`[` "The most important distinction between [, [[ and $ is that the [ can select more than one element whereas the other two select a single element."
On Thu, Jun 15, 2017 at 11:33 AM, ce <zadig_1 at excite.com> wrote:
Hi I have a list : mylist <- list( a = NULL, b = 1, c = 2 )
mylist[1]
$a NULL
is.null(mylist[1])
[1] FALSE
is.null(mylist$a)
[1] TRUE why? I need to use mylist[1]
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Huzefa Khalil PhD Candidate, Department of Political Science, University of Michigan