array of lists in r

Question

Suppose if I want to have 10 element array each element is a list/map. I am doing this:

x = array(list(), 10)
x[1][[ \"a\" ]] = 1
Warning message:
In x[1][[\         


        

Answer 1

If you really want to do this, then, because the elements of the lists in each element of the array do not have names, you can't index by a character vector. In your example, there is no x[1][[ "a" ]]:

> x[1][[ "a" ]]
NULL

If there are no names then you need to index by a numeric:

> x[1][[ 1 ]] <- 1
[1] 1

It would seem more logical to have a list though than an array:

> y <- vector(mode = "list", length = 10)
> y
[[1]]
NULL

[[2]]
NULL

[[3]]
NULL

[[4]]
NULL

[[5]]
NULL
....