plots on are rendered differentially depending on used libraries

Once in a while it is worth to update some libraries, even for working shiny-applications as new nad useful features are introduced. So I did it for my app and observed that the plots do look differentially now, more like as if they were created with plotly. For example the spacing in the font is different.

More importantly, the function to generate scientific labels on the y-axis isn't working correctly anymore.

I wanted to revise this function anyway, as I am not 100% happy with this (as the x in the middle isn't hardcoded but interpreted differentially, e.g. when saved as pdf it's not one piece of text but multiple) - now it seems I have to.

While working on a RepEx I noticed an even more strange behaviour! There is no difference when I only include the ggplot library, but when using the tidyverse.
local with tidyverse (quite identical to local with ggplot and on shinyapps with ggplot):

on shinyapps with tidyverse:

I assume it's the default-rendering engine for ggsave (it's ragg now?)
Obviously for the full app I need more functions from the tidyverse than just ggplot.
And I don't want to need to upload the app everytime I want to test something.

Any ideas how to make the local and shinyapps-version responding identically?
Or any idea how to fix the scientific axis issue?



# Define UI 
ui <- fluidPage(
    column(width = 4, plotOutput("Plot_ggplot")),
    column(width = 4, imageOutput("Plot_png") ),
    column(width = 4, imageOutput("Plot_jpg") )

# Define server logic 
server <- function(input, output) {
  # Function for exp. numbers on Y-Axis 
  nice_scientific <- function(l) {
    # turn in to character string in scientific notation
    l <- format(l, scientific = TRUE)
    l <- gsub("0e\\+00","0",l)
    # quote the part before the exponent to keep all the digits
    l <- gsub("^(.*)e", "'\\1'e", l)
    # turn the 'e+' into plotmath format
    l <- gsub("e\\+","e",l)
    l <- gsub("e", "%*%10^", l)
    # return this as an expression
  # Data
  PlotData = data.frame(Condition = c("A","B","C","D"),
                        Value = c(30000,500000,400000,200000))
  # Base Plot
  Plot = reactive({
  ggplot(PlotData, aes(x = Condition, y = Value)) + 
      geom_col(width = 0.8) +
      theme_minimal(base_size = 16) + 
      scale_y_continuous(labels = nice_scientific) 

  # PlotOutput
  output$Plot_ggplot = renderPlot({
      Plot() + labs(title = "Plot with ggplot") })
  # save plot as png
  output$Plot_png = renderImage({
      plot = Plot() + labs(title = "Plot as png"),
      bg = "white", dpi = 80, width=15, height = 13, units = "cm")

    # Return the filename for the download function 
    list(src = "Plot.png", contentType = 'image/png')
  }, deleteFile = FALSE)
  # save plot as jpg 
  output$Plot_jpg = renderImage({
           plot = Plot() + labs(title = "Plot as jpg"),
           bg = "white", dpi = 80, width=15, height = 13, units = "cm")

  # Return the filename for the download function 
    list(src = "Plot.jpg", contentType = 'image/jpg')
  }, deleteFile = FALSE)

# Run the application 
shinyApp(ui = ui, server = server)
R version 4.3.0 (2023-04-21 ucrt)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 11 x64 (build 22621)

Matrix products: default

[1] LC_COLLATE=German_Germany.utf8  LC_CTYPE=German_Germany.utf8    LC_MONETARY=German_Germany.utf8 LC_NUMERIC=C                   
[5] LC_TIME=German_Germany.utf8    

time zone: Europe/Berlin
tzcode source: internal

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
 [1] lubridate_1.9.2 forcats_1.0.0   stringr_1.5.0   dplyr_1.1.2     purrr_1.0.1     readr_2.1.4     tidyr_1.3.0     tibble_3.2.1   
 [9] ggplot2_3.4.2   tidyverse_2.0.0 shiny_1.7.4    

loaded via a namespace (and not attached):
 [1] writexl_1.4.2       tidyselect_1.2.0    vipor_0.4.5         farver_2.1.1        fastmap_1.1.1       tweenr_2.0.2       
 [7] promises_1.2.0.1    shinyjs_2.1.0       digest_0.6.31       timechange_0.2.0    mime_0.12           lifecycle_1.0.3    
[13] ellipsis_0.3.2      magrittr_2.0.3      compiler_4.3.0      sass_0.4.6          rlang_1.1.1         tools_4.3.0        
[19] igraph_1.4.3        utf8_1.2.3          yaml_2.3.7          knitr_1.43          labeling_0.4.2      rARPACK_0.11-0     
[25] plyr_1.8.8          mapproj_1.2.11      RColorBrewer_1.1-3  BiocParallel_1.34.2 withr_2.5.0         grid_4.3.0         
[31] polyclip_1.10-4     fansi_1.0.4         xtable_1.8-4        colorspace_2.1-0    extrafontdb_1.0     scales_1.2.1       
[37] MASS_7.3-60         pals_1.7            dichromat_2.0-0.1   cli_3.6.1           ellipse_0.4.5       rmarkdown_2.22     
[43] ragg_1.2.5          generics_0.1.3      rstudioapi_0.14     RSpectra_0.16-1     tzdb_0.4.0          reshape2_1.4.4     
[49] readxl_1.4.2        cachem_1.0.8        ggbeeswarm_0.7.2    ggforce_0.4.1       maps_3.4.1          parallel_4.3.0     
[55] cellranger_1.1.0    matrixStats_1.0.0   vctrs_0.6.2         Matrix_1.5-4        jsonlite_1.8.5      hms_1.1.3          
[61] ggrepel_0.9.3       beeswarm_0.4.0      systemfonts_1.0.4   jquerylib_0.1.4     glue_1.6.2          codetools_0.2-19   
[67] mixOmics_6.24.0     cowplot_1.1.1       stringi_1.7.12      gtable_0.3.3        later_1.3.1         extrafont_0.19     
[73] munsell_0.5.0       pillar_1.9.0        htmltools_0.5.5     R6_2.5.1            textshaping_0.3.6   evaluate_0.21      
[79] lattice_0.21-8      memoise_2.0.1       bslib_0.5.0         corpcor_1.6.10      httpuv_1.6.9        Rcpp_1.0.10        
[85] gridExtra_2.3       Rttf2pt1_1.3.12     xfun_0.39           pkgconfig_2.0.3    

Okay it is ragg!
Since ggplot 3.3.4. "ggsave() now uses ragg to render raster output if ragg is available."
So whenever I additionally load the library ragg, (or tidyverse or officeR) ragg is present and is used.
And somehow this uses a different font, in which the mathplot rendering of the multiplication symbol is different / not working correctly.
I can also reverse this effect by adding "device = png" to the ggsave function, to restore the local (windows) version in, at least for the saved plots.
But still I cannot predict the final outcome unless it was uploaded to shinyapps, as I don't have an ubuntu-linux here at hand.

Maybe always using ragg along with register_font() is an option?

Some related links: