Saving to PDF Using Palatino Roman Doesn't Show Negative Signs with Plots.jl

[ggarza]

As stated in the topic title, saving a plot to a pdf when using the fontfamily “Palatino Roman” doesn’t show negative signs.

Here’s a MWE:

using Plots
f(x) = x^2-3
pl = plot(f, -3, 3, fontfamily="Palatino Roman")
savefig(pl, "plot.png")
savefig(pl, "plot.pdf")

and these are the resulting plots:
First the plot as a png:

And now a screenshot of the plot as a pdf (a screenshot because I can’t upload pdfs):

I am using Plots v1.16.8

[ggarza]

I’m posting here instead of submitting an issue because I don’t want to spam Github by submitting an issue that’s known. I searched but couldn’t find any issue similar. I also don’t know if I should submit an issue for Plots.jl or one of the backends.

[stevengj]

What backend are you using?

It looks like the backend has text rendering that doesn’t support fallback fonts, and Palatino Roman is missing a glyph for the minus sign (U+2212).

[ggarza]

I believe it’s GR (or the default). I created a new environment with Plots.jl as the only package added.

I’ve uploaded the Project.toml and Manifest.toml files here: Manifest.toml · GitHub

[stevengj]

@ggarza

I believe it’s GR (or the default).

GR doesn’t support fallback fonts last I heard, which means that it won’t render any Unicode characters that aren’t present in your font, and hence you need to use a font with sufficient Unicode coverage. See also the discussion in Error with unicode labels in GR backend · Issue #791 · JuliaPlots/Plots.jl · GitHub

[ggarza]

Thank you, @stevengj

In case anyone runs into this thread, there is a another issue submitted here: Error about savefig · Issue #2938 · JuliaPlots/Plots.jl · GitHub

[jheinen]

GR can not embed fonts into the PDF output. You will have to provide a “Palatino” font with the corresponding UTF-8 glyphs (using the GKS_FONT_DIRS environment) and use GR’s internal text renderer (using GR.settextfontprec(..., GR.TEXT_PRECISION_OUTLINE)). I can try to provide an example next week …

[jheinen]

ENV["GKS_FONT_DIRS"] = pwd()

using GR

beginprint("font-ex.pdf")

settextalign(GR.TEXT_HALIGN_CENTER, GR.TEXT_VALIGN_HALF)

font = loadfont("Rockness.ttf")
settextfontprec(font, GR.TEXT_PRECISION_OUTLINE)
setcharheight(0.06)

text(0.5, 0.5, "The quick brown fox jumps over the lazy dog")

font = loadfont("Palatino-Roman.ttf")
settextfontprec(font, GR.TEXT_PRECISION_OUTLINE)
setcharheight(0.03)

text(0.5, 0.4, "– The quick brown fox jumps over the lazy dog –")

updatews()

endprint()

[jheinen]

You will find the above fonts here.