theme(aspect.ratio=value) fails for integer values

[GabrielHoffman]

I found a problem with ggplot2() using theme(aspect.ratio=value). Plotting fails if value is an integer

Here is the code to reproduce the bug:

library(ggplot2)

# set the aspect.ratio
ratio = nrow(sleep)

# the ratio is an "integer"
is(ratio)
#> [1] "integer"             "double"              "numeric"            
#> [4] "vector"              "data.frameRowLabels"

# Fails
ggplot(sleep, aes(group, ID, fill=extra)) +
    geom_tile() +
    theme(aspect.ratio=ratio)
#> Error in `mapply()`:
#> ! The `aspect.ratio` theme element must be a <numeric> object.
#> Backtrace:
#>      ▆
#>   1. ├─base::tryCatch(...)
#>   2. │ └─base (local) tryCatchList(expr, classes, parentenv, handlers)
#>   3. │   ├─base (local) tryCatchOne(...)
#>   4. │   │ └─base (local) doTryCatch(return(expr), name, parentenv, handler)
#>   5. │   └─base (local) tryCatchList(expr, names[-nh], parentenv, handlers[-nh])
#>   6. │     └─base (local) tryCatchOne(expr, names, parentenv, handlers[[1L]])
#>   7. │       └─base (local) doTryCatch(return(expr), name, parentenv, handler)
#>   8. ├─base::withCallingHandlers(...)
#>   9. ├─base::saveRDS(...)
#>  10. ├─base::do.call(...)
#>  11. ├─base (local) `<fn>`(...)
#>  12. └─global `<fn>`(input = base::quote("milky-cub_reprex.R"))
#>  13.   └─rmarkdown::render(input, quiet = TRUE, envir = globalenv(), encoding = "UTF-8")
#>  14.     └─knitr::knit(knit_input, knit_output, envir = envir, quiet = quiet)
#>  15.       └─knitr:::process_file(text, output)
#>  16.         ├─base::withCallingHandlers(...)
#>  17.         ├─base::withCallingHandlers(...)
#>  18.         ├─knitr:::process_group(group)
#>  19.         └─knitr:::process_group.block(group)
#>  20.           └─knitr:::call_block(x)
#>  21.             └─knitr:::block_exec(params)
#>  22.               └─knitr:::eng_r(options)
#>  23.                 ├─knitr:::in_input_dir(...)
#>  24.                 │ └─knitr:::in_dir(input_dir(), expr)
#>  25.                 └─knitr (local) evaluate(...)
#>  26.                   └─evaluate::evaluate(...)
#>  27.                     └─evaluate:::evaluate_call(...)
#>  28.                       ├─evaluate (local) handle(...)
#>  29.                       │ └─base::try(f, silent = TRUE)
#>  30.                       │   └─base::tryCatch(...)
#>  31.                       │     └─base (local) tryCatchList(expr, classes, parentenv, handlers)
#>  32.                       │       └─base (local) tryCatchOne(expr, names, parentenv, handlers[[1L]])
#>  33.                       │         └─base (local) doTryCatch(return(expr), name, parentenv, handler)
#>  34.                       ├─base::withCallingHandlers(...)
#>  35.                       ├─base::withVisible(value_fun(ev$value, ev$visible))
#>  36.                       └─knitr (local) value_fun(ev$value, ev$visible)
#>  37.                         └─knitr (local) fun(x, options = options)
#>  38.                           ├─base::withVisible(knit_print(x, ...))
#>  39.                           ├─knitr::knit_print(x, ...)
#>  40.                           └─knitr:::knit_print.default(x, ...)
#>  41.                             └─evaluate (local) normal_print(x)
#>  42.                               ├─base::print(x)
#>  43.                               └─ggplot2:::print.ggplot(x)
#>  44.                                 ├─ggplot2::ggplot_gtable(data)
#>  45.                                 └─ggplot2:::ggplot_gtable.ggplot_built(data)
#>  46.                                   └─ggplot2:::plot_theme(plot)
#>  47.                                     └─base::mapply(validate_element, theme, names(theme), MoreArgs = list(element_tree = get_element_tree()))
#>  48.                                       └─ggplot2 (local) `<fn>`(dots[[1L]][[5L]], dots[[2L]][[5L]], element_tree = `<named list>`)
#>  49.                                         └─cli::cli_abort(...)
#>  50.                                           └─rlang::abort(...)

# Success after casting ratio to be "numeric"
ggplot(sleep, aes(group, ID, fill=extra)) +
    geom_tile() +
    theme(aspect.ratio=as.numeric(ratio))

sessionInfo()
#> R version 4.3.0 (2023-04-21)
#> Platform: x86_64-apple-darwin22.4.0 (64-bit)
#> Running under: macOS Ventura 13.4
#> 
#> Matrix products: default
#> BLAS:   /Users/gabrielhoffman/prog/R-4.3.0/lib/libRblas.dylib 
#> LAPACK: /usr/local/Cellar/r/4.3.0_1/lib/R/lib/libRlapack.dylib;  LAPACK version 3.11.0
#> 
#> locale:
#> [1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8
#> 
#> time zone: America/New_York
#> tzcode source: internal
#> 
#> attached base packages:
#> [1] stats     graphics  grDevices utils     datasets  methods   base     
#> 
#> other attached packages:
#> [1] ggplot2_3.4.2
#> 
#> loaded via a namespace (and not attached):
#>  [1] vctrs_0.6.3      cli_3.6.1        knitr_1.43       rlang_1.1.1     
#>  [5] xfun_0.39        generics_0.1.3   labeling_0.4.2   glue_1.6.2      
#>  [9] colorspace_2.1-0 htmltools_0.5.5  scales_1.2.1     fansi_1.0.4     
#> [13] rmarkdown_2.22   grid_4.3.0       evaluate_0.21    munsell_0.5.0   
#> [17] tibble_3.2.1     fastmap_1.1.1    yaml_2.3.7       lifecycle_1.0.3 
#> [21] compiler_4.3.0   dplyr_1.1.2      fs_1.6.2         pkgconfig_2.0.3 
#> [25] farver_2.1.1     digest_0.6.31    R6_2.5.1         tidyselect_1.2.0
#> [29] reprex_2.0.2     utf8_1.2.3       pillar_1.9.0     magrittr_2.0.3  
#> [33] tools_4.3.0      withr_2.5.0      gtable_0.3.3

[teunbrand]

Thanks for the report!
This seems to apply more broadly to all theme elements that allow numeric input, e.g.:

library(ggplot2)

ggplot(mpg, aes(displ, hwy, colour = cty)) +
  geom_point() +
  theme(legend.position = c(1L, 1L))
#> Error in `mapply()`:
#> ! The `legend.position` theme element must be a <character/numeric>
#>   object.

^{Created on 2023-07-27 with reprex v2.0.2}