CODEWITHSUNDEEP
r
Lllewellyn
Lllewellyn

Reputation: 21

Extracting vector from embedded list in R

This feels like it should be easy, but I can't work it out. I have a list of lists, in the same form as below (but much, much, longer ...)

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

I want to extract a vector of the "y" values, ie c(4,8,6). Do you know how to do this? I have tried searching to no avail.

Thanks

Upvotes: 2

Views: 375

Answers (2)

Maurits Evers
Maurits Evers

Reputation: 50728

Or using purrr:

library(purrr)
map_dbl(mylist, "y")
#[1] 4 8 6

Upvotes: 3

jdobres
jdobres

Reputation: 11957

What you want is to iterate over each item of mylist and retrieve only the "y" values. Easy with sapply:

sapply(mylist, '[[', 'y')

[1] 4 8 6

Upvotes: 2

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