Proposed fix for Latex sub/super-scripts in legends

[t-bltg]

Fixes #3558:

1. Fix height computation by retaining the maximum legend height, for each serie;
2. Allow changing the height factor via the extra_kwargs mecanism.

Discussion:
Change [1.] does modify some reference images, but I think the fix is justified. Only applying [2.] allows fixing the OP issue, without changing the default legend sizes.

MWE

using LaTeXStrings
using Random; Random.seed!(1234)
using Plots; gr()

main() = begin
  y1, y2 = rand(100), rand(100)
  histogram(
    y1, ylims=(0, 50), label=L"\left\Vert\beta_{1}^{2}-\beta_{2}^{2}\right\Vert",
    extra_kwargs=Dict(:subplot=>Dict(:legend_hfactor=>1.25))
  )
  histogram!(y2, label=L"\left\Vert\beta_{2}^{2}-\beta_{3}^{2}\right\Vert", legendfontsize=10)
  png("foo")
end

main()

With PR

Without using extra_kwargs:

Using :legend_hfactor=>1.25:

Without PR

Default behavior modification (example # 23)

With PR

Without PR

[daschw]

Looks great!

[t-bltg]

@ptoche, is this approach ok for you ?

[ptoche]

This looks great, thanks for putting this together! :-)

[lmiq]

I get still the same issue:

(jl_4g90hf) pkg> status GR
      Status `/tmp/jl_4g90hf/Project.toml`
  [28b8d3ca] GR v0.61.0

[t-bltg]

You can use legend_hfactor > 1 to fine tune the spacing.

[lmiq]

That does not seem to have any effect on my plot. Am I doing something wrong?

Or isn't this released yet as of 0.61.0?

[t-bltg]

Please see the working example at #3598 (comment).

extra_kwargs are explained here.

This alternative also works:

using LaTeXStrings
using Random; Random.seed!(1234)
using Plots; gr()

main() = begin
  y1, y2 = rand(100), rand(100)
  histogram(y1, ylims=(0, 50), label=L"\left\Vert\beta_{1}^{2}-\beta_{2}^{2}\right\Vert")
  histogram!(
    y2, label=L"\left\Vert\beta_{2}^{2}-\beta_{3}^{2}\right\Vert", legendfontsize=10,
    legend_hfactor=1.25, extra_kwargs=:subplot
  )
  png("foo")
end

main()

[lmiq]

Ok, thanks, so this MWE works:

julia> plot(rand(10),label=L"2\pi")

julia> plot!(rand(10),label=L"2\pi",legend_hfactor=1.5,extra_kwargs=:subplot)

The extra arguments have to be in the same plot! command as the second plot, otherwise it does not do anything (meaning, running plot!(legend_hfactor=1.5,extra_kwargs=:subplot) it not the way it works.