How can I make a list of lists in R?
Using your example::
list1 <- list()
list1[1] = 1
list1[2] = 2
list2 <- list()
list2[1] = 'a'
list2[2] = 'b'
list_all <- list(list1, list2)
Use '[[' to retrieve an element of a list:
b = list_all[[1]]
b
[[1]]
[1] 1
[[2]]
[1] 2
class(b)
[1] "list"
You can easily make lists of lists
list1 <- list(a = 2, b = 3)
list2 <- list(c = "a", d = "b")
mylist <- list(list1, list2)
mylist is now a list that contains two lists. To access list1 you can use mylist[[1]]
. If you want to be able to something like mylist$list1
then you need to do somethingl like
mylist <- list(list1 = list1, list2 = list2)
# Now you can do the following
mylist$list1
Edit: To reply to your edit. Just use double bracket indexing
a <- list_all[[1]]
a[[1]]
#[1] 1
a[[2]]
#[1] 2
If you are trying to keep a list
of list
s (similar to python
's list.append()
) then this might work:
a <- list(1,2,3)
b <- list(4,5,6)
c <- append(list(a), list(b))
> c
[[1]]
[[1]][[1]]
[1] 1
[[1]][[2]]
[1] 2
[[1]][[3]]
[1] 3
[[2]]
[[2]][[1]]
[1] 4
[[2]][[2]]
[1] 5
[[2]][[3]]
[1] 6