Remove common list elements in lists of lists in R

Question

I have a list of lists, I would like to remove the common elements between these sublists.

For example

mylist = list(
c(1, 2, 3, 4),
c(2, 5, 6, 7),
c(4, 2, 8, 9)
)

becomes

mylist = list(
c(1, 3),
c(5, 6, 7),
c(8, 9)
)

I first created a list of the common elements and tried to substrate this list from the sublist but it does not work

common_elements = list(Reduce(intersect, mylist))
mylist = mylist[!(mylist %in% common_elements)]

Could you help me? Thank you !

Answer 1

Based on the update, it is a list of vector s. Convert the list to a two column tibble/data.frame with enframe , get the count of distinct elements to filter and split back to a list of vector s

library(dplyr)
library(tibble)
library(tidyr)
enframe(mylist) %>%     
    unnest(value) %>%
    group_by(value) %>%
    filter(n_distinct(name) == 1) %>% 
    with(., split(value, name)) %>%
    unname

-output

[[1]]
[1] 1 3

[[2]]
[1] 5 6 7

[[3]]
[1] 8 9

data

mylist <- list(c(1, 2, 3, 4), c(2, 5, 6, 7), c(4, 2, 8, 9))

Answer 2

A base R option

> lut <- table(unlist(mylist))

> comm <- as.numeric(names(lut[lut > 1]))

> lapply(mylist, function(x) x[!x %in% comm])
[[1]]
[1] 1 3

[[2]]
[1] 5 6 7

[[3]]
[1] 8 9

data

mylist <- list(1:4, c(2, 5:7), c(4, 2, 8, 9))

Answer 3

A tidyverse option for a list of lists.

library(tidyverse)

ls %>%
  enframe() %>%
  unnest(value) %>%
  mutate(dupes = if_else(duplicated(value) == T, as.integer(value), NA_integer_)) %>%
  filter(!value %in% dupes) %>%
  group_by(name) %>%
  mutate(X = list(value)) %>%
  ungroup() %>%
  distinct(X) %>%
  deframe()

# [[1]]
# [[1]][[1]]
# [1] 1
# 
# [[1]][[2]]
# [1] 3
# 
# 
# [[2]]
# [[2]][[1]]
# [1] 5
# 
# [[2]][[2]]
# [1] 6
# 
# [[2]][[3]]
# [1] 7
# 
# 
# [[3]]
# [[3]][[1]]
# [1] 8
# 
# [[3]][[2]]
# [1] 9

Data

ls <- list(list(1, 2, 3, 4), list(2, 5, 6, 7), list(4, 2, 8, 9))