In summarise draws, a function that returns a character changes all columns to character

[n-kall]

If a summary function that returns a character is used in summarise_draws, it makes all columns <chr> which messes up formatting.

example_draws() |>
   summarise_draws(x, char_fun = \(x) "word", mean)

Returns

# A tibble: 10 × 3
   variable char_fun      mean
   <chr>    <chr>         <chr>
 1 mu       word          4.1799990610081
 2 tau      word          4.16356885610418
 3 theta[1] word          6.74893947963962
 4 theta[2] word          5.25331634990726
 5 theta[3] word          3.04393475572924
 6 theta[4] word          4.85842854299997
 7 theta[5] word          3.22258991784476
 8 theta[6] word          3.98696993634695
 9 theta[7] word          6.5030995214442
10 theta[8] word          4.56520199862817

This could be fixed by using type.convert(out, as.is = TRUE) on the output tibble in summarise_draws_helper

[mjskay]

This suggests to me that the output is being bound into a matrix (which requires a single type) and then converted to a data frame later, which it should probably not be. Rather than potentially round-tripping through a string (with the possibility for information loss) I would suggest binding results together into a data frame directly, which should be more efficient anyway.

[n-kall]

This suggests to me that the output is being bound into a matrix

Yes, this is indeed the case

[paul-buerkner]

I agree. that would make sense

n-kall @.***> schrieb am Do., 14. März 2024, 18:52:

This suggests to me that the output is being bound into a matrix

Yes, this is indeed the case

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[n-kall]

It seems this is also caused by the behaviour of unlist, which results in a vector, and when performed on a list with different types inside, will convert them all to the same (in this case character). This unlisting is done to handle summary functions that return multiple elements (e.g. quantile2).

However, I don't know of a base R equivalent to purrr::flatten which would do what we want in this case (returning a list, but without nesting).