[R] flatten a list to a "true" list

[Christian Hoffmann]

Hi,

I want to flatten a list:

"flatten"(list(a=1,b=2),list(c=3,d=4)) -> L <- list(a=1,b=2,c=3,d=4)

which is

 > L
$a
[1] 1

$b
[1] 2

$c
[1] 3

$d
[1] 4

 > L[1]
$a
[1] 1

 > L[[1]]
[1] 1

What I used so far is

M <- unlist(c(list(a=1,b=2),list(c=3,d=4))), but this gives

 > M
a b c d
1 2 3 4
 > M[1]
a
1
 > M[[1]]
[1] 1

This shows that L has named "components", but L is a named vector.

What would be the functions

L <- F1(M)
M <- F2(L)

like?

Generally:

Flatten a tree down to level "n", where level 0 is the root.

I searched the net under "flatten", but it showed only unlist.

Thanks for help
Christian

-- 
Dr. Christian W. Hoffmann,
Swiss Federal Research Institute WSL
Mathematics + Statistical Computing
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christian.hoffmann at wsl.ch
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