CODEWITHSUNDEEP
arraysrtidyversetibble
Kim
Kim

Reputation: 4298

Cannot convert tibble to array in R?

I was trying to convert a very simple 1x4 tibble to an array:

library(tidyverse)
temp <- tibble(x=0,y=1,z=1,w=1)
array(temp)

It gives me the following error messages:

Error in mapply(FUN = f, ..., SIMPLIFY = FALSE) : zero-length inputs cannot be mixed with those of non-zero length In addition: Warning messages: 1: In is.na(x) : is.na() applied to non-(list or vector) of type 'NULL' 2: In is.na(x) : is.na() applied to non-(list or vector) of type 'NULL'

Within the array function it seems like dim(data) <- dim part is the problem... I did figure out a solution, which is to turn the tibble into a dataframe:

array(as.data.frame(temp))

But I'm not quite sure why I have to go through an extra step. Could somebody tell me what I'm missing?

Upvotes: 4

Views: 4282

Answers (1)

Kim
Kim

Reputation: 4298

As of tibble version 1.4.2, this behavior can no longer be reproduced. For future references, I leave the following record: 

> library(tidyverse)
> versions::installed.versions("tibble")
[1] "1.4.2"
> temp <- tibble(x=0,y=1,z=1,w=1)

> array(temp)
# A tibble: 1 x 4
  <dbl> <dbl> <dbl> <dbl>
1    0.    1.    1.    1.
> array(as.data.frame(temp))
1 0 1 1 1
> simplify2array(temp)
x y z w 
0 1 1 1

> dim(array(temp))
[1] 1 4
> dim(as.data.frame(array(temp)))
[1] 1 4
> dim(simplify2array(temp))
NULL

> class(array(temp))
[1] "tbl_df"     "tbl"        "data.frame"
> class(as.data.frame(array(temp)))
[1] "data.frame"
> class(simplify2array(temp))
[1] "numeric"

> as.array(temp)
Error in `dimnames<-.data.frame`(`*tmp*`, value = list(n)) : 
  invalid 'dimnames' given for data frame

I could use simplify2array to create 3D arrays such as follows, but unfortunately I do not quite remember what I was going for at the time when I asked this question.

simplify2array(by(temp, temp$x, as.matrix))

Upvotes: 4

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