I have the following nested list called l (dput below):
> l
$A
$A$`1`
[1] 1 2 3
$A$`2`
[1] 3 2 1
$B
$B$`1`
[1] 2 2 2
$B$`2`
[1] 3 4 3
I would like to convert this to a grouped dataframe where A and B are the first group column and 1 and 2 are the subgroups with respective values. The desired output should look like this:
group subgroup values
1 A 1 1
2 A 1 2
3 A 1 3
4 A 2 3
5 A 2 2
6 A 2 1
7 B 1 2
8 B 1 2
9 B 1 2
10 B 2 3
11 B 2 4
12 B 2 3
As you can see A and B are the main group and 1 and 2 are the subgroups. Using purrr::flatten(l) or unnest doesn't work. So I was wondering if anyone knows how to convert a nested list to a grouped row dataframe?
dput of l:
l <- list(A = list(`1` = c(1, 2, 3), `2` = c(3, 2, 1)), B = list(`1` = c(2,
2, 2), `2` = c(3, 4, 3)))
Using stack and rowbind with id:
data.table::rbindlist(lapply(l, stack), idcol = "id")
# id values ind
# 1: A 1 1
# 2: A 2 1
# 3: A 3 1
# 4: A 3 2
# 5: A 2 2
# 6: A 1 2
# 7: B 2 1
# 8: B 2 1
# 9: B 2 1
# 10: B 3 2
# 11: B 4 2
# 12: B 3 2