Issue with x11() and font in R

Question

I am having problems changing font in R. For some reasons, it seems that R can not find the font I am asking (any of them, actually). I double-checked that the fonts are indeed installed on my system (Linux Mint 20.3). It looks like to be related to x11() , but it appears to be supported on my machine.

Any ideas appreciated.

capabilities()
#>        jpeg         png        tiff       tcltk         X11        aqua 
#>        TRUE        TRUE        TRUE       FALSE        TRUE       FALSE 
#>    http/ftp     sockets      libxml        fifo      cledit       iconv 
#>        TRUE        TRUE        TRUE        TRUE       FALSE        TRUE 
#>         NLS       Rprof     profmem       cairo         ICU long.double 
#>        TRUE        TRUE       FALSE        TRUE        TRUE        TRUE 
#>     libcurl 
#>        TRUE

library(ggplot2)

ggplot() +
  labs(x = quote(delta)) +
  theme(text = element_text(family = "Roboto"))
#> Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)): font family not
#> found in X11 font database

#> Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)): font family not
#> found in X11 font database

#> Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)): font family not
#> found in X11 font database

#> Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)): font family not
#> found in X11 font database

#> Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)): font family not
#> found in X11 font database

#> Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)): font family not
#> found in X11 font database

#> Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)): font family not
#> found in X11 font database

#> Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)): font family not
#> found in X11 font database

#> Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)): font family not
#> found in X11 font database

#> Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)): font family not
#> found in X11 font database

#> Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)): font family not
#> found in X11 font database

#> Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)): font family not
#> found in X11 font database

#> Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)): font family not
#> found in X11 font database

#> Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)): font family not
#> found in X11 font database
#> Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
#> family not found in X11 font database

#> Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
#> family not found in X11 font database

#> Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
#> family not found in X11 font database

#> Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
#> family not found in X11 font database

#> Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
#> family not found in X11 font database

#> Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
#> family not found in X11 font database

#> Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
#> family not found in X11 font database

#> Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
#> family not found in X11 font database

#> Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
#> family not found in X11 font database

#> Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
#> family not found in X11 font database

#> Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
#> family not found in X11 font database

#> Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
#> family not found in X11 font database

#> Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
#> family not found in X11 font database

#> Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
#> family not found in X11 font database
#> Warning in grid.Call.graphics(C_text, as.graphicsAnnot(x$label), x$x, x$y, :
#> font family not found in X11 font database

#> Warning in grid.Call.graphics(C_text, as.graphicsAnnot(x$label), x$x, x$y, :
#> font family not found in X11 font database

#> Warning in grid.Call.graphics(C_text, as.graphicsAnnot(x$label), x$x, x$y, :
#> font family not found in X11 font database

#> Warning in grid.Call.graphics(C_text, as.graphicsAnnot(x$label), x$x, x$y, :
#> font family not found in X11 font database

#> Warning in grid.Call.graphics(C_text, as.graphicsAnnot(x$label), x$x, x$y, :
#> font family not found in X11 font database

^{Created on 2022-01-18 by the reprex package (v2.0.1)}

Answer 1

Here's what I did after following my own (slightly misspelled) advice:

?X11Fonts

The followed the example and executed its code:

if(capabilities()[["X11"]]) withAutoprint({
X11Fonts()
X11Fonts("mono")
utopia <- X11Font("-*-utopia-*-*-*-*-*-*-*-*-*-*-*-*")
X11Fonts(utopia = utopia)
})

No error and "utopia" was there in the listed fonts the next time I ran X11Fonts() , so I tried with "Roboto" (in an Ubuntu 18.04 box).

 Roboto <- X11Font("-*-roboto-*-*-*-*-*-*-*-*-*-*-*-*")
 X11Fonts(Roboto = Roboto)
#-------------------
> X11Fonts()
$serif
[1] "-*-times-%s-%s-*-*-%d-*-*-*-*-*-*-*"

$sans
[1] "-*-helvetica-%s-%s-*-*-%d-*-*-*-*-*-*-*"


#---snipped

$Roboto
[1] "-*-roboto-%s-%s-*-*-%d-*-*-*-*-*-*-*"

Looks like Roboto is now mine. (I have no idea what it looks like.)

After executing:

 library(ggplot2)

ggplot() +
  labs(x = quote(delta)) +
  theme(text = element_text(family = "Roboto"))

.... I now see an unmarkerked plot area with a Greek lowercase delta as the label in an x11 window, which will disappear after I execute dev.off() .