Calculate median across multiple lists vertically

Question

Say I have three lists, each one containing the result of a test:

listA <- list(10, 5, 4)
listB <- list(2, 8, 3)
listC <- list(1, 5, 3)

I want to find the median of those lists by position vertically. So the results for each position would be:

• First position: 2
• Second position: 5
• Third position: 3

How can I achieve this in R? Thanks in advance.

Answer 1

You can use Map() to combine the three lists vertically, and then compute each median by lapply().

sapply(Map(c, listA, listB, listC), median)

# [1] 2 5 3

---

You can also use transpose() from purrr.

library(purrr)

map_dbl(transpose(mget(ls(pattern = 'list'))), ~ median(flatten_dbl(.x)))

# [1] 2 5 3

Or using pmap():

pmap_dbl(mget(ls(pattern = 'list')), ~ median(c(...)))

# [1] 2 5 3