plots on shinyapps.io are rendered differentially depending on used libraries

Matthias · November 23, 2023, 10:55am

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?

Matthias · November 23, 2023, 10:57am

Repex:

#library(ggplot2)
library(tidyverse)
library(shiny)

# Define UI 
ui <- fluidPage(
    titlePanel("PlotRenderTest"),
    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
    parse(text=l)
  }
  
  # 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({
    ggsave("Plot.png",
      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({
    ggsave("Plot.jpg",
           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)

sessionInfo()
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


locale:
[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

Matthias · November 27, 2023, 8:39am

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 shinyapps.io, 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.

ismirsehregal · November 27, 2023, 10:01am

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

Some related links:

github.com/r-lib/ragg

Request: allow user to specify Symbol font

opened 04:23PM - 27 Aug 21 UTC

closed 11:13AM - 06 Oct 21 UTC

christyray

With the release of R 4.0.0, the default `x11()`, `png()`, `jpeg()`, `tiff()`, `…bmp()`, `svg()`, `cairo_pdf()`, and `cairo_ps()` devices accept a `symbolfamily` argument to let the user change the font used for symbols in an image ([source](https://developer.r-project.org/Blog/public/2020/04/17/changes-to-symbol-fonts-for-cairo-graphics-devices/index.html)). With Base R `png()`: ``` r library(ggplot2) library(ragg) library(scales) greek <- as.data.frame(c("alpha", "beta", "gamma")) names(greek) <- "greek" p <- ggplot(greek, aes(x = greek, y = 1)) + theme( plot.title = element_blank(), axis.title = element_blank(), axis.ticks = element_blank(), axis.text.x = element_text(family = "Fira Sans", size = 16), axis.text.y = element_blank() ) + scale_x_discrete(name = NULL, labels = label_parse()) ggsave( "greek_base.png", plot = p, device = png, width = 3, height = 1, dpi = 600, type = "cairo", symbolfamily = cairoSymbolFont("Fira Sans") ) ``` <sup>Created on 2021-08-27 by the [reprex package](https://reprex.tidyverse.org) (v2.0.1)</sup> This gives this plot, withe the "Fira Sans" font used: ![greek_base](https://user-images.githubusercontent.com/17527594/131157860-cf82742e-c20d-4230-b736-0a393f6c8e71.png) With `ragg::agg_png()`: ``` r library(ggplot2) library(ragg) library(scales) greek <- as.data.frame(c("alpha", "beta", "gamma")) names(greek) <- "greek" p <- ggplot(greek, aes(x = greek, y = 1)) + theme( plot.title = element_blank(), axis.title = element_blank(), axis.ticks = element_blank(), axis.text.x = element_text(family = "Fira Sans", size = 16), axis.text.y = element_blank() ) + scale_x_discrete(name = NULL, labels = label_parse()) ggsave( "greek_ragg.png", plot = p, device = ragg::agg_png, width = 3, height = 1, dpi = 600 ) ``` <sup>Created on 2021-08-27 by the [reprex package](https://reprex.tidyverse.org) (v2.0.1)</sup> Which gives this plot, using the system default "Symbol" font: ![greek_ragg](https://user-images.githubusercontent.com/17527594/131157077-07866522-3e2d-46f7-8b14-f5cec29e88cb.png) <details> <summary>Session Info</summary> ```r > sessionInfo() R version 4.1.1 (2021-08-10) Platform: x86_64-apple-darwin17.0 (64-bit) Running under: macOS Big Sur 11.5.2 Matrix products: default LAPACK: /Library/Frameworks/R.framework/Versions/4.1/Resources/lib/libRlapack.dylib locale: [1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8 attached base packages: [1] stats graphics grDevices utils datasets methods base other attached packages: [1] scales_1.1.1 ragg_1.1.3 ggplot2_3.3.5 loaded via a namespace (and not attached): [1] highr_0.9 pillar_1.6.2 compiler_4.1.1 tools_4.1.1 [5] digest_0.6.27 evaluate_0.14 lifecycle_1.0.0 tibble_3.1.4 [9] gtable_0.3.0 pkgconfig_2.0.3 rlang_0.4.11 reprex_2.0.1 [13] rstudioapi_0.13 cli_3.0.1 DBI_1.1.1 yaml_2.2.1 [17] xfun_0.25 fastmap_1.1.0 withr_2.4.2 dplyr_1.0.7 [21] knitr_1.33 fs_1.5.0 generics_0.1.0 vctrs_0.3.8 [25] systemfonts_1.0.2 grid_4.1.1 tidyselect_1.1.1 glue_1.4.2 [29] R6_2.5.1 textshaping_0.3.5 processx_3.5.2 fansi_0.5.0 [33] rmarkdown_2.10 clipr_0.7.1 callr_3.7.0 purrr_0.3.4 [37] magrittr_2.0.1 ps_1.6.0 ellipsis_0.3.2 htmltools_0.5.2 [41] assertthat_0.2.1 colorspace_2.0-2 labeling_0.4.2 utf8_1.2.2 [45] munsell_0.5.0 crayon_1.4.1 ``` </details> As far as I can tell, there isn't currently a way to specify the font to use for symbols with the `ragg` package. It would be helpful if there were because the default font does not match stylistically with many sans serif fonts.