`geom_sf` can't deal with NA-containing `linewidth`

[zhenglukai]

An error occurs when I attempt to plot parcellated map data with geom_sf():

! mixture of missing and non-missing values for fontsize

It seems that the bug reported in #3483 still exists for the argument linewidth.

Here is the code to reproduce the bug:

library(tidyverse)
library(ggseg); library(ggsegSchaefer)
data("schaefer17_100")
df = data.frame(
  region = unique(schaefer17_100$data$region)[-1],
  val = 1:100,
  ln_thk = c(rep(.6, 6), rep(.3, 94))
)

## works fine when `linewidth` is a constant
df %>%
  brain_join(schaefer17_100) %>% 
  ggplot() +
  geom_sf(aes(#linewidth = I(ln_thk),
              fill = val), 
          linewidth = .3
          ) +
  scale_size_identity()
#> merging atlas and data by 'region'

## lines below create error
df %>%
  brain_join(schaefer17_100) %>% 
  ggplot() +
  geom_sf(aes(linewidth = I(ln_thk),
              fill = val), 
          #linewidth = .3
          ) +
  scale_size_identity()
#> merging atlas and data by 'region'
#> Error in `geom_sf()`:
#> ! Problem while converting geom to grob.
#> ℹ Error occurred in the 1st layer.
#> Caused by error in `checkNA()`:
#> ! mixture of missing and non-missing values for fontsize

#> 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("pure-tayra_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. │       ├─knitr:::process_group(group)
#>  18. │       └─knitr:::process_group.block(group)
#>  19. │         └─knitr:::call_block(x)
#>  20. │           └─knitr:::block_exec(params)
#>  21. │             └─knitr:::eng_r(options)
#>  22. │               ├─knitr:::in_input_dir(...)
#>  23. │               │ └─knitr:::in_dir(input_dir(), expr)
#>  24. │               └─knitr (local) evaluate(...)
#>  25. │                 └─evaluate::evaluate(...)
#>  26. │                   └─evaluate:::evaluate_call(...)
#>  27. │                     ├─evaluate (local) handle(...)
#>  28. │                     │ └─base::try(f, silent = TRUE)
#>  29. │                     │   └─base::tryCatch(...)
#>  30. │                     │     └─base (local) tryCatchList(expr, classes, parentenv, handlers)
#>  31. │                     │       └─base (local) tryCatchOne(expr, names, parentenv, handlers[[1L]])
#>  32. │                     │         └─base (local) doTryCatch(return(expr), name, parentenv, handler)
#>  33. │                     ├─base::withCallingHandlers(...)
#>  34. │                     ├─base::withVisible(value_fun(ev$value, ev$visible))
#>  35. │                     └─knitr (local) value_fun(ev$value, ev$visible)
#>  36. │                       └─knitr (local) fun(x, options = options)
#>  37. │                         ├─base::withVisible(knit_print(x, ...))
#>  38. │                         ├─knitr::knit_print(x, ...)
#>  39. │                         └─knitr:::knit_print.default(x, ...)
#>  40. │                           └─evaluate (local) normal_print(x)
#>  41. │                             ├─base::print(x)
#>  42. │                             └─ggplot2:::print.ggplot(x)
#>  43. │                               ├─ggplot2::ggplot_gtable(data)
#>  44. │                               └─ggplot2:::ggplot_gtable.ggplot_built(data)
#>  45. │                                 └─ggplot2:::by_layer(...)
#>  46. │                                   ├─rlang::try_fetch(...)
#>  47. │                                   │ ├─base::tryCatch(...)
#>  48. │                                   │ │ └─base (local) tryCatchList(expr, classes, parentenv, handlers)
#>  49. │                                   │ │   └─base (local) tryCatchOne(expr, names, parentenv, handlers[[1L]])
#>  50. │                                   │ │     └─base (local) doTryCatch(return(expr), name, parentenv, handler)
#>  51. │                                   │ └─base::withCallingHandlers(...)
#>  52. │                                   └─ggplot2 (local) f(l = layers[[i]], d = data[[i]])
#>  53. │                                     └─l$draw_geom(d, layout)
#>  54. │                                       └─ggplot2 (local) draw_geom(..., self = self)
#>  55. │                                         └─self$geom$draw_layer(...)
#>  56. │                                           └─ggplot2 (local) draw_layer(..., self = self)
#>  57. │                                             └─base::lapply(...)
#>  58. │                                               └─ggplot2 (local) FUN(X[[i]], ...)
#>  59. │                                                 ├─rlang::inject(self$draw_panel(data, panel_params, coord, !!!params))
#>  60. │                                                 └─self$draw_panel(data, panel_params, coord, na.rm = FALSE, legend = "polygon")
#>  61. │                                                   └─ggplot2 (local) draw_panel(..., self = self)
#>  62. │                                                     └─ggplot2:::sf_grob(...)
#>  63. │                                                       └─grid::gpar(...)
#>  64. │                                                         └─grid:::validGP(list(...))
#>  65. │                                                           └─grid (local) checkNA("fontsize")
#>  66. │                                                             └─base::stop(...)
#>  67. └─base::.handleSimpleError(...)
#>  68.   └─rlang (local) h(simpleError(msg, call))
#>  69.     └─handlers[[1L]](cnd)
#>  70.       └─cli::cli_abort(...)
#>  71.         └─rlang::abort(...)

^{Created on 2023-02-24 with reprex v2.0.2}

[yutannihilation]

Thanks, confirmed. Here's the minimal version.

library(ggplot2)

pts <- sf::st_sf(
  geometry = sf::st_sfc(
    sf::st_linestring(matrix(0:3, nrow = 2)),
    sf::st_linestring(matrix(2:5, nrow = 2))
  ),
  linewidth = c(1, NA)
)

# works fine because size doesn't work :)
ggplot(pts) + geom_sf(aes(size = linewidth))

# error
ggplot(pts) + geom_sf(aes(linewidth = linewidth))
#> Error in `geom_sf()`:
#> ! Problem while converting geom to grob.
#> ℹ Error occurred in the 1st layer.
#> Caused by error in `checkNA()`:
#> ! mixture of missing and non-missing values for fontsize

Looking at the fix I added on #3491, it seems the problem is linewidth is no longer non_missing_aes because GeomPath$non_missing_aes doesn't include linewidth. We should probably call GeomPath$handle_na() to handle the missing values correctly.

ggplot2/R/geom-sf.R

Line 175 in 9e9b49b

remove[is_line] <- detect_missing(x, c(GeomPath$required_aes, GeomPath$non_missing_aes))[is_line]