gt() can affect results of operations that are based on random number generation

[seb09]

Hi, I recently experienced unexpected behavior of {gt} regarding operations that are based on random number generation. When I added a gt to an Rmd, I noticed a slight change of results of a machine learning model, indicating that gt() changes the seed of the random number generator.

library(gt)

set.seed(123)
sample(1:6, size = 1)
#> [1] 3

set.seed(123)
mtcars |> head(1) |> gt()

mpg	cyl	disp	hp	drat	wt	qsec	vs	am	gear	carb
21	6	160	110	3.9	2.62	16.46	0	1	4	4

sample(1:6, size = 1)
#> [1] 6

^{Created on 2024-11-03 with reprex v2.1.1}

Session info

sessioninfo::session_info()
#> ─ Session info ───────────────────────────────────────────────────────────────
#>  setting  value
#>  version  R version 4.4.1 (2024-06-14)
#>  os       macOS Sonoma 14.7
#>  system   aarch64, darwin20
#>  ui       X11
#>  language (EN)
#>  collate  en_US.UTF-8
#>  ctype    en_US.UTF-8
#>  tz       Europe/Berlin
#>  date     2024-11-03
#>  pandoc   3.2 @ /Applications/RStudio.app/Contents/Resources/app/quarto/bin/tools/aarch64/ (via rmarkdown)
#> 
#> ─ Packages ───────────────────────────────────────────────────────────────────
#>  package     * version date (UTC) lib source
#>  cli           3.6.3   2024-06-21 [1] CRAN (R 4.4.0)
#>  digest        0.6.37  2024-08-19 [1] CRAN (R 4.4.1)
#>  dplyr         1.1.4   2023-11-17 [1] CRAN (R 4.4.0)
#>  evaluate      1.0.1   2024-10-10 [1] CRAN (R 4.4.1)
#>  fansi         1.0.6   2023-12-08 [1] CRAN (R 4.4.0)
#>  fastmap       1.2.0   2024-05-15 [1] CRAN (R 4.4.0)
#>  fs            1.6.5   2024-10-30 [1] CRAN (R 4.4.1)
#>  generics      0.1.3   2022-07-05 [1] CRAN (R 4.4.0)
#>  glue          1.8.0   2024-09-30 [1] CRAN (R 4.4.1)
#>  gt          * 0.11.1  2024-10-04 [1] CRAN (R 4.4.1)
#>  htmltools     0.5.8.1 2024-04-04 [1] CRAN (R 4.4.0)
#>  knitr         1.48    2024-07-07 [1] CRAN (R 4.4.0)
#>  lifecycle     1.0.4   2023-11-07 [1] CRAN (R 4.4.0)
#>  magrittr      2.0.3   2022-03-30 [1] CRAN (R 4.4.0)
#>  pillar        1.9.0   2023-03-22 [1] CRAN (R 4.4.0)
#>  pkgconfig     2.0.3   2019-09-22 [1] CRAN (R 4.4.0)
#>  R6            2.5.1   2021-08-19 [1] CRAN (R 4.4.0)
#>  reprex        2.1.1   2024-07-06 [1] CRAN (R 4.4.0)
#>  rlang         1.1.4   2024-06-04 [1] CRAN (R 4.4.0)
#>  rmarkdown     2.28    2024-08-17 [1] CRAN (R 4.4.0)
#>  rstudioapi    0.17.1  2024-10-22 [1] CRAN (R 4.4.1)
#>  sass          0.4.9   2024-03-15 [1] CRAN (R 4.4.0)
#>  sessioninfo   1.2.2   2021-12-06 [1] CRAN (R 4.4.0)
#>  tibble        3.2.1   2023-03-20 [1] CRAN (R 4.4.0)
#>  tidyselect    1.2.1   2024-03-11 [1] CRAN (R 4.4.0)
#>  utf8          1.2.4   2023-10-22 [1] CRAN (R 4.4.0)
#>  vctrs         0.6.5   2023-12-01 [1] CRAN (R 4.4.0)
#>  withr         3.0.2   2024-10-28 [1] CRAN (R 4.4.1)
#>  xfun          0.48    2024-10-03 [1] CRAN (R 4.4.1)
#>  xml2          1.3.6   2023-12-04 [1] CRAN (R 4.4.0)
#>  yaml          2.3.10  2024-07-26 [1] CRAN (R 4.4.0)
#> 
#>  [1] /Users/<xxx>/Library/R/arm64/4.4/library
#>  [2] /Library/Frameworks/R.framework/Versions/4.4-arm64/Resources/library
#> 
#> ──────────────────────────────────────────────────────────────────────────────

This seems to be induced by the random_id() function.

I'd suggest to use withr::with_seed() together with a seed that is e.g. derived from the last digits of the users system time to avoid touching the system settings and potentially messing with the seeds that are set by the user.
(Thanks, @maike2011, for the idea)

[olivroy]

I am not sure, but if this is something important for you. As a workaround you can supply id directly in the gt call.

i.e.

mtcars |> gt(id = "xyz")

This way, random_id() will not be called.

See also r-lib/testthat#1736 (comment)

Also this https://r-pkgs.org/code.html#sec-code-onLoad-onAttach