[R] data.frame with a column containing an array

[Georg Kindermann]

Thanks!
 
No, to be consistent with what I get with a matrix I think it should be like:

x <- data.frame(id = DFA$id[1])
x$ar <- DFA$ar[1, , , drop = FALSE]

str(x)
#'data.frame': 1 obs. of 2 variables:
# $ id: int 1
# $ ar: int [1, 1:2, 1:2] 1 3 5 7

Georg
 
 

Gesendet: Dienstag, 09. Mai 2023 um 09:32 Uhr
Von: "Rui Barradas" <ruipbarradas using sapo.pt>
An: "Georg Kindermann" <Georg.Kindermann using gmx.at>, r-help using r-project.org
Betreff: Re: [R] data.frame with a column containing an array
Às 11:52 de 08/05/2023, Georg Kindermann escreveu:
> Dear list members,
>
> when I create a data.frame containing an array I had expected, that I get a similar result, when subsetting it, like having a matrix in a data.frame. But instead I get only the first element and not all values of the remaining dimensions. Differences are already when creating the data.frame, where I can use `I` in case of a matrix but for an array I am only able to insert it in a second step.
>
> DFA <- data.frame(id = 1:2)
> DFA[["ar"]] <- array(1:8, c(2,2,2))
>
> DFA[1,]
> # id ar
> #1 1 1
>
> DFM <- data.frame(id = 1:2, M = I(matrix(1:4, 2)))
>
> DFM[1,]
> # id M.1 M.2
> #1 1 1 3
>
> The same when trying to use merge, where only the first value is kept.
>
> merge(DFA, data.frame(id = 1))
> # id ar
> #1 1 1
>
> merge(DFM, data.frame(id = 1))
> # id M.1 M.2
> #1 1 1 3
>
> Is there a way to use an array in a data.frame like I can use a matrix in a data.frame?
>
> I am using R version 4.3.0.
>
> Kind regards,
> Georg
>
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Hello,

Are you looking for something like this?


DFA <- data.frame(id = 1:2)
DFA[["ar"]] <- array(1:8, c(2,2,2))

DFA$ar[1, , ]
#> [,1] [,2]
#> [1,] 1 5
#> [2,] 3 7


Hope this helps,

Rui Barradas