[BUG] Log scale axis labels not brace-wrapped in PGFPlotsX

[ivan-boikov]

Details

Log scale axis labels with a power of two symbols or more is broken

using Plots
pgfplotsx()
PGFPlotsX.latexengine!(PGFPlotsX.PDFLATEX) # doubt it's relevant, but just in case - I use it
plot(
    plot([1e-5, 1e10]; title="Automatic labels",
        yticks=[1e-5, 1e0, 1e10]),
    plot([1e-5, 1e10]; title="Manual labels",
        yticks=([1e-5, 1e0, 1e10], ["\$10^{-5}\$", "\$10^{0}\$", "\$10^{10}\$"])),
    legend=:none, yscale=:log10
)

Looking at the generated .tex

savefig("plot.tex")
open("plot.tex") do f
    for line in eachline(f)
        i0 = findfirst("yticklabels=", line)
        i1 = findfirst("ytick=", line)
        if !isnothing(i0)
            println(line[i0[1]:i1[1]-3])
        end
    end
end

yticklabels={{$10^-5$,$10^0$,$10^10$}}
yticklabels={{$10^{-5}$,$10^{0}$,$10^{10}$}}

we see that the power is not wrapped automatically.
The behavior changed between v1.38.1 and v1.38.2, so I suspect #4618 was almost there - the tests only covered single-digit powers.

Looks like it can be fixed here

Plots.jl/src/axes.jl

Line 115 in 5f29256

Dict{Symbol,Function}(:log10 => x -> "10^$x", :log2 => x -> "2^$x", :ln => x -> "e^$x")

by changing to

Dict{Symbol,Function}(:log10 => x -> "10^{$x}", :log2 => x -> "2^{$x}", :ln => x -> "e^{$x}")

though it's a low-level function and I am not confident enough to open a PR.

Backends

This bug occurs on ( insert x below )

Backend	yes	no	untested
gr (default)		x
pythonplot			x
plotlyjs			x
pgfplotsx	x
unicodeplots		x	x
inspectdr			x
gaston			x

Versions

Plots.jl version: v1.38.6
Backend version (]st -m <backend(s)>):

[28b8d3ca] GR v0.71.7
[8314cec4] PGFPlotsX v1.5.3
[b8865327] UnicodePlots v3.4.0

Output of versioninfo():

Julia Version 1.8.1
Commit afb6c60d69a (2022-09-06 15:09 UTC)
Platform Info:
  OS: Linux (x86_64-linux-gnu)
  CPU: 12 × AMD Ryzen 5 3600 6-Core Processor
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-13.0.1 (ORCJIT, znver2)
  Threads: 1 on 12 virtual cores

[ivan-boikov]

Actually, scratch that "fix", it changes font in GR to computer modern and who knows what mayhem it causes in other backends

[ivan-boikov]

Looking at it again, I think this would be a better fix: add

labelfunc(scale::Symbol, backend::PGFPlotsXBackend) = labelfunc_tex(scale)

to src/backends/pgfplotsx.jl

[t-bltg]

Ping @daschw for #4618.

though it's a low-level function and I am not confident enough to open a PR.

Nah, you should open a PR with added tests, it's the best way to get your issue fixed.
Anyone can start contributing (tips here: https://docs.juliaplots.org/stable/contributing) !