how to find mean of elements in a list of lists in R

Question

I have a list of lists like:

> head(mylist)
[[1]]
 [1] 0.000 0.067 0.400 0.733 1.000 1.000 1.000 1.000 1.000 1.000 1.000 1.000 1.000
[[2]]
 [1] 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.400 0.867 1.000
[[3]]
 [1] 0.000 0.000 0.000 0.000 0.000 0.000 0.133 0.467 0.933 1.000 1.000 1.000 1.000
[[4]]
 [1] 0.267 0.600 0.933 0.933 1.000 1.000 1.000 1.000 1.000 1.000 1.000 1.000 1.000

and I would like to build a new vector that contains the element wise mean of each sublists element, like at the first place there should be the result of

mean(c(mylist[[1]][1], mylist[[2]][1], mylist[[3]][1], mylist[[4]][1])). 

I think it should be something along the line:

lapply(mylist, mean)

but in this case I just have the mean of each sublist.

Answer 1

You can combine the elements to a matrix and use colMeans:

mylist <- list(1:5, 1:5, 1:5)

colMeans(do.call(rbind, mylist))
# [1] 1 2 3 4 5