image titles do not render properly

Question

I am trying to run the example shiny app (I added the options(encoding = 'UTF-8')):

options(encoding = 'UTF-8')

library(shiny)

# Define UI for application that draws a histogram
ui <- fluidPage(
   
   # Application title
   titlePanel("Old Faithful Geyser Data"),
   
   # Sidebar with a slider input for number of bins 
   sidebarLayout(
      sidebarPanel(
         sliderInput("bins",
                     "Number of bins:",
                     min = 1,
                     max = 50,
                     value = 30)
      ),
      
      # Show a plot of the generated distribution
      mainPanel(
         plotOutput("distPlot")
      )
   )
)

# Define server logic required to draw a histogram
server <- function(input, output) {
   
   output$distPlot <- renderPlot({
      # generate bins based on input$bins from ui.R
      x    <- faithful[, 2] 
      bins <- seq(min(x), max(x), length.out = input$bins + 1)
      
      # draw the histogram with the specified number of bins
      hist(x, breaks = bins, col = 'darkgray', border = 'white')
   })
}

# Run the application 
shinyApp(ui = ui, server = server)

and the image has not encoded the names (titles).

UPDATE

I tried to use par(family ="Ubuntu Mono") in the R script and it works. But, it doesn't work in the shiny app (tried it inside render plot).

Does this happen only with Shiny output, or also in your regular graphics device if you just do `hist(faithful[, 2])` in your R session? — Mikko Marttila, Mar 17 '22 at 13:16
Ah in that case this looks like a similar issue: https://stackoverflow.com/q/59796585/4550695 — Mikko Marttila, Mar 17 '22 at 13:27
@MikkoMarttila:If I use `par(family ="Ubuntu Mono")` in the regular session, it works. But not in shiny app. — George, Mar 17 '22 at 14:11
Try setting that inside the `renderPlot()` function. `par()` needs to be called after the graphics device that renders the image has been opened. — Mikko Marttila, Mar 17 '22 at 14:20
That's strange. Would you update your question to show what exactly you are trying? — Mikko Marttila, Mar 17 '22 at 14:24
Sorry, I meant showing the code that you tried. If I put a `par(family = "serif")` first thing inside the expression in `renderPlot()`, the font in the output changes accordingly. I don't see why this would be any different. — Mikko Marttila, Mar 17 '22 at 14:50
@MikkoMarttila:Hmm.as I can see, yes it works but I am trying with ggplot (inside render plot) which doesn't work. But, I am not sure that is a permanent solution. Typing in every plot call the `par` — George, Mar 17 '22 at 14:56
Looks like you can also pass the option as a named argument to `renderPlot()`, so you could do `renderPlot({ ... }, family = "Ubuntu Mono")` and it should also work. That might be a bit more feasible. For a permanent solution I think you'd have to solve the font issue on your machine, which I have no idea how to do. — Mikko Marttila, Mar 17 '22 at 15:01
@MikkoMarttila:Yes! That works! In shiny. In normal session , If I use ggplot , how ca I set it globally? Because with `par` it doesn't work. — George, Mar 17 '22 at 15:07
Yeah, ggplot doesn't take font values from `par`. You'd need to add something like `theme(text = element_text(family = "Ubuntu Sans"))` to your plot. See more about changing fonts in ggplot here: https://stackoverflow.com/q/34522732/4550695 — Mikko Marttila, Mar 17 '22 at 15:11
@MikkoMarttila:Basically, this `theme_set(theme_gray(base_size = 20, base_family = 'Font Name' ))` for globally — George, Mar 17 '22 at 15:19

score 1 · Accepted Answer · answered Mar 17 '22 at 15:31

This looks like a font conflict. You could circumvent it by setting a custom font available on your system that does get rendered correctly.

For base graphics, use par(family = "serif") or renderPlot(..., family = "serif") in Shiny. For ggplot2 graphics, set theme(text = element_text(family = "serif")) for an individual plot, or use base_family in supported themes, e.g. theme_gray(base_family = "serif").

In all of the above, replace "serif" with the font you want to use. For example, you specifically mentioned "Ubuntu Mono" rendering correctly in your case.

image titles do not render properly

1 Answers1