Gaston 2.0 not working in Plots.jl

[ay111]

The code below generates error

using Plots
gaston()

x = range(0, 0.5, length = 100)
y = sin.(2*pi*10*x)
plot(x, y)

Output on Julia REPL
┌ Warning: `Gaston` 2.0.0 is not compatible with this version of `Plots`. The declared compatibility is 1.
└ @ Plots C:\Users\HP\.julia\packages\Plots\iPlTg\src\backends.jl:55


ERROR: UndefVarError: `newfigure` not defined in `Gaston`
Suggestion: check for spelling errors or missing imports.
Stacktrace:
  [1] _create_backend_figure(plt::Plots.Plot{Plots.GastonBackend})
    @ Plots C:\Users\HP\.julia\packages\Plots\iPlTg\src\backends\gaston.jl:8
  [2] #invokelatest#2
    @ .\essentials.jl:1055 [inlined]
  [3] invokelatest
    @ .\essentials.jl:1052 [inlined]
  [4] _plot_setup(plt::Plots.Plot{Plots.GastonBackend}, plotattributes::Dict{Symbol, Any}, kw_list::Vector{Dict{Symbol, Any}})
    @ Plots C:\Users\HP\.julia\packages\Plots\iPlTg\src\pipeline.jl:205
  [5] plot_setup!(plt::Plots.Plot{Plots.GastonBackend}, plotattributes::Dict{Symbol, Any}, kw_list::Vector{Dict{Symbol, Any}})
    @ Plots C:\Users\HP\.julia\packages\Plots\iPlTg\src\pipeline.jl:148
  [6] recipe_pipeline!(plt::Any, plotattributes::Any, args::Any)
    @ RecipesPipeline C:\Users\HP\.julia\packages\RecipesPipeline\BGM3l\src\RecipesPipeline.jl:89
  [7] _plot!(plt::Plots.Plot, plotattributes::Any, args::Any)
    @ Plots C:\Users\HP\.julia\packages\Plots\iPlTg\src\plot.jl:223
  [8] plot(::Any, ::Vararg{Any}; kw...)
    @ Plots C:\Users\HP\.julia\packages\Plots\iPlTg\src\plot.jl:102
  [9] plot(::Any, ::Any)
    @ Plots C:\Users\HP\.julia\packages\Plots\iPlTg\src\plot.jl:93
 [10] top-level scope
    @ REPL[5]:1

[mbaz]

Correct; Gaston v2.0 is a breaking release and its Plots.jl backend has not been updated yet. The backend is maintained by @t-bltg, who may have time to update it in the next few weeks/months.

For the time being I recommend staying on v1.

[t-bltg]

@mbaz, I've started working on porting https://github.com/JuliaPlots/Plots.jl/blob/v2/PlotsBase/ext/GastonExt.jl to Gaston v2 (I'm the original author of this file).

However, the internal structure of Gaston changed in v2, and for example SubPlots and Layout disappeared ...

I have difficulties porting the code since https://mbaz.github.io/Gaston.jl/v2/migrate.html doesn't cover all of our use cases in Plots.

I think you are the most aware of what changed, so could you have a look at our code and propose replacements ?

[mbaz]

I'd like to try provide the information you need, and then update migrate.html once I have a clearer idea of what is missing. There's a layout example in Plots.jl tutorial here. The way to produce this plot in Gaston is like this:

f = Figure(multiplot = "layout 3,1", autolayout = false)
plot(f[1], x, y1)
plot(f[2], x, y2)
plot(f[3], x, y3)

Internally, what is going on is this. The object f has the following fields:

• autolayout, defaults to true, but in this case we need to set it to false. When autolayout is true, Gaston creates a layout as described here.
• multiplot, which is a string used with gnuplot's set multiplot command.
• gp_proc and handle which we can ignore for now (these are set automatically when a Figure is instantiated).
• axes is the important one here. It is a vector of Axis; each element corresponds to a subplot. Each subplot can have its own configuration (grid, title, ticks, etc) and a set of curves (each curve is of type Plot).

So, the same figure as above could be built programatically as follows:

• Create the first plot p1 with data x and y1.
• Create the first axis a1 and insert p1.
• Repeat for the next two subplots.
• Create a vector A with elements a1, a2 and a3.
• Create a figure, set its multiplot field and set its field axes to A.

Is this useful? I will try to study your current port and come up with ideas on how to migrate it, but unfortunately time is scarce at the moment (and for at least two more weeks).

[mbaz]

Here's a concrete way to build the plot from the Plots.jl tutorial, also showing how to set curve and axes properties:

f = Figure(multiplot = "layout 3,1", autolayout = false)
p1 = Gaston.Plot(x, y1, "lc 'red'")
a1 = Gaston.Axis(p1)
p2 = Gaston.Plot(x, y2, "w p ps 2")
a2 = Gaston.Axis("set grid", p2)
p3 = Gaston.Plot(x, y3)
a3 = Gaston.Axis("set title 'p3'", p3)
push!(f, a1, a2, a3)  # push all axes to f.axes

The functions parse_settings and parse_plotline are useful to convert key-value pairs into a string that gnuplot understands.

[t-bltg]

Thanks for the hints.

Using Base.retry_load_extensions(), I manage to precompile using Gaston, but it currently deadlocks in Plots => fixed !

You can follow the changes in JuliaPlots/Plots.jl#5632.

[t-bltg]

@ay111 the backport PR to Plots v1 is on the way : JuliaPlots/Plots.jl#5633.

If CI passes I'll release a version of Plots this afternoon.

EDIT: JuliaRegistries/General#147605