在R语言中按名称合并列表的多个子列表

Hey there! Let's tackle this problem. You want to merge all your sublists by their named elements (a, b, c, etc.)—so all the a vectors from sublists 1 to 50 get concatenated into one big a vector, same for b and c.

Here are two straightforward approaches, using base R and the tidyverse's purrr package, which work seamlessly even for 40-50 sublists:

Base R Solution #

You can use do.call() to pass all your sublists as arguments to mapply(), which will handle element-wise concatenation automatically:

# First, let's create a sample list with 50 sublists (mimicking your structure)
set.seed(123) # For reproducible random values
l <- lapply(1:50, function(i) {
  list(
    a = sample(1:100, 3),
    b = sample(1:100, 3),
    c = sample(1:100, 3)
  )
})
names(l) <- as.character(1:50) # Name sublists "1" to "50"

# Merge by named elements
l2 <- do.call(mapply, c(FUN = c, l, SIMPLIFY = FALSE))

How this works: #

• do.call(mapply, ...) takes every sublist in l and feeds them as individual arguments to mapply().
• FUN = c tells mapply() to concatenate all matching named elements (e.g., all a vectors from sublists 1-50, all b vectors, etc.).
• SIMPLIFY = FALSE ensures the result stays a list (instead of coercing to a matrix if possible), which matches your desired structure.

Tidyverse (purrr) Solution #

If you prefer tidyverse syntax, purrr::transpose() is perfect here—it rearranges your list to group by element names instead of sublist numbers. Then you just concatenate each group:

library(purrr)

# Using the same sample list l from above
l2 <- map(transpose(l), c)

How this works: #

• transpose(l) flips the list structure: instead of list("1" = list(a, b, c), "2" = list(a, b, c), ...), you get list(a = list(a1, a2, ..., a50), b = list(b1, b2, ..., b50), c = list(c1, c2, ..., c50)).
• map(..., c) applies the concatenation function c to each element in the transposed list, turning each list of small vectors into a single combined vector.

Both methods will give you exactly the structure you need—l2 will have a, b, c elements, each being the concatenation of all corresponding vectors from your 40-50 sublists.

内容的提问来源于stack exchange，提问作者PK1998