Plotting symbols fails in PDF

Question

I have the following code to create a plot. On the x- and y-axes there are symbols that appear on the screen, in a JPEG when I save my plot in that format, but not when I save the plot as a PDF.

Is there alternative symbol to my \u2030 that will print in my PDF or another solution to my problem? See examples below of the correct (JPEG format) and the incorrect (PDF) plots .

plot(c(-1,1), c(-1,1), bty = "n", type= "n", las = 1, cex.lab = 1.5, cex.axis = 1.25, main = NULL, 
ylab=expression(paste("Correlation Coefficient (r) for ", delta ^{15},"N"," \u0028","\u2030","\u0029")), 
xlab=expression(paste("Correlation Coefficient (r) for ", delta ^{13},"C"," \u0028","\u2030","\u0029")))
axis(1, at = seq(-1.0, 1.0, by = 0.1), labels = F, pos = 0, cex.axis = 0.05, tcl = 0.25)
axis(2, at = seq(-1.0, 1.0, by = 0.1), labels = F, pos = 0, cex.axis = 0.05, tcl = 0.25)

Answer 1

The problem is that your default font does not have "‰" (which I would speak as "per mil") as the glyph that is produced with \u0028. You need to change to a font that does have that glyph:

?pdfFonts

This is what I get with my setup where there is no problem (at least as I understand ti.)

> str(pdfFonts("sans"))
List of 1
 $ sans:List of 3
  ..$ family  : chr "Helvetica"
  ..$ metrics : chr [1:5] "Helvetica.afm" "Helvetica-Bold.afm" "Helvetica-Oblique.afm" "Helvetica-BoldOblique.afm" ...
  ..$ encoding: chr "default"
  ..- attr(*, "class")= chr "Type1Font"

Answer 2

You probably have to change the encoding. On my mac this gets me the ‰ sign:

pdf('test.pdf',encoding="MacRoman")
plot.new()
text(0,labels="\u2030")
dev.off()

Look in the ‘enc’ directory of package grDevices for available encodings and try them out.

Answer 3

I had the same problem to save in PDF form with MAC. I am saving with ggsave and MacRoman.

ggsave("Name_of_your_file.pdf", #choose your own name
   encoding="MacRoman",
   width = 20, #size that you want
   height = 20, #size that you want
   units = "cm")

It will save your file where you saved your R file.

Answer 4

Depending on whether or not your system has the needed true font files [hint: install the showtext package and use View(font_files()] you should be able to get available unicode characters into pdf files by

1. Exporting first to a temporary file, say "temp.png"
2. Exporting to the pdf file using pdf() or cairo_pdf(), say "UnicodeToPDF.pdf"
3. Combine the use of grid.arrange (from gridExtra), rasterGrob (from grid), and readPNG (from png) to insert the temp.png file into the UnicodeToPDF.pdf file
4. Removing the "temp.png" file

#--- A function to install missing packages and load them all
myfxLoadPackages = function (PACKAGES) {
  lapply(PACKAGES, FUN = function(x) {
    if (suppressWarnings(!require(x, character.only = TRUE))) {
      install.packages(x, dependencies = TRUE, repos = "https://cran.rstudio.com/")
    }
  })
  lapply(PACKAGES, FUN = function(x) library(x, character.only = TRUE))
}

packages = c("gridExtra","grid","png")
myfxLoadPackages(packages)

#--- The trick to get unicode characters being printed on pdf files:
#--- 1. Create a temporary file, say "temp.png"
#--- 2. Create the pdf file using pdf() or cairo_pdf(), say "UnicodeToPDF.pdf"
#--- 3. Combine the use of grid.arrange (from gridExtra), rasterGrob (from grid), and readPNG (from png) to insert the
#       temp.png file into the UnicodeToPDF.pdf file
Corrvalues = data.frame(X=seq(-0.8,0.8,0.2),
                        Y=seq(-0.8,0.8,0.2),
                        PCH=-c(10122:10130)) #--- This is equivalent to using unicode characters 10122-10130 (note the use of -)
#--- Refer to http://xahlee.info/comp/unicode_index.html to see more unicode character integers

png("temp.png", width=11, height=11, units="in", res=300)
par(mar=c(4,5,3,1) + 0.1)
plot(c(-1,1), c(-1,1), bty = "n", type= "n", las = 1, cex.lab = 1.5, cex.axis = 1.25, main = NULL, 
     ylab=expression(paste("Correlation Coefficient (r) for ", delta ^{15},"N"," \u0028","\u2030","\u0029")), 
     xlab=expression(paste("Correlation Coefficient (r) for ", delta ^{13},"C"," \u0028","\u2030","\u0029")))
axis(1, at = seq(-1.0, 1.0, by = 0.1), labels = F, pos = 0, cex.axis = 0.05, tcl = 0.25)
axis(2, at = seq(-1.0, 1.0, by = 0.1), labels = F, pos = 0, cex.axis = 0.05, tcl = 0.25)
points(Corrvalues$X,Corrvalues$X,pch=Corrvalues$PCH,cex=2.75,col="#FF7F00")
dev.off()

pdf("UnicodeToPDF.pdf", width=11, height=11)
grid.arrange(
  rasterGrob(
    readPNG(
      "temp.png",
      native=F
    )
  )
)
dev.off()

file.remove("temp.png")

The following image has been added to follow up on Konrad Rudolph's comments.