Coerce Large List of Lists to Data Frame Keeping List Property

Question

I have a large list of lists full of IDs with the following properties

list1 <- c(145540,145560, 157247, 145566)
list2 <- c(166927, NA, NA, NA)
list3 <- c(145592, 145560, 145566, NA)
list <- list(list1, list2, list3)

Now I would like to coerce this large list to a data.frame while keeping the list properties of the nested lists. The desired output should look like this:

list1 list2 list3
145540 166927 145592
145560 NA 145560
157247 NA 145566
145566 NA NA

Thank you very much for your help.

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Please explain how you encountered the problem you're trying to solve, and any difficulties that have prevented you from solving it yourself. — cptwonton, Feb 05 '18 at 18:03
You don't have any nested lists there. You are working with three atomic vectors. Let's have a `dput()` of the desired result. Not sure what the final result is supposed to be, but `as.data.frame(list)` should be fine (but with ugly names). — Rich Scriven, Feb 05 '18 at 18:13

Felipe Alvarenga · Accepted Answer · 2018-02-05T18:24:13.403

0

Just rowbind together your lists of vectors (assuming you have just vectors as elements of your upper level list)

as.data.frame(sapply(list, rbind))
     V1   V2   V3
1 145540 166927 145592
2 145560     NA 145560
3 157247     NA 145566
4 145566     NA     NA

edited Feb 05 '18 at 18:24

answered Feb 05 '18 at 18:11

Felipe Alvarenga

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Thanks but this produces a matrix not a data frame. – quantmarketing Feb 05 '18 at 18:23
just change it to a data.frame – Felipe Alvarenga Feb 05 '18 at 18:23

score 0 · Answer 2 · answered Feb 06 '18 at 07:56

do.call(cbind.data.frame,list)
  c(145540, 145560, 157247, 145566) c(166927, NA, NA, NA)
1                            145540                166927
2                            145560                    NA
3                            157247                    NA
4                            145566                    NA
  c(145592, 145560, 145566, NA)
1                        145592
2                        145560
3                        145566
4                            NA
> Reduce(cbind.data.frame,list)
    init x[[i]] x[[i]]
1 145540 166927 145592
2 145560     NA 145560
3 157247     NA 145566
4 145566     NA     NA
> Reduce(cbind,list)
       init              
[1,] 145540 166927 145592
[2,] 145560     NA 145560
[3,] 157247     NA 145566
[4,] 145566     NA     NA

Then you can set the names.

Although on the other hand if the names were preset ie list <- list(list1=list1, list2=list2, list3=list3) then

do.call(cbind.data.frame,list)

   list1  list2  list3
1 145540 166927 145592
2 145560     NA 145560
3 157247     NA 145566
4 145566     NA     NA

Coerce Large List of Lists to Data Frame Keeping List Property

2 Answers2