Cannot plot contours in both CairoMakie and GLMakie

[tomchor]

When using CairoMakie to animate contours, I get the following error:

ERROR: LoadError: AssertionError: length(positions) == length(colors)

I posted this on slack a while ago but couldn't solve the issue, so I've decided to post here this time. I also remember someone online somewhere with the same issue as me and no solution, but I can't find that anymore.

Here's the MWE to reproduce this:

using CairoMakie

fig = Figure()
n = Observable(1)

ax = Axis(fig[1, 1])

N = 10
A = randn(N, N, N)
Aₙ = @lift A[:,:,$n]
contour!(ax, Aₙ)

frames = 1:N

record(fig, "mwe.mp4", frames, framerate=14) do frame
    @info "Plotting frame $frame..."
    n[] = frame
end

PS: The error doesn't happen in GLMakie, only usingo CairoMakie. Also for some reason the error seems to happen only in the second frame (i.e. the first frame plots fine), but when I manually try to plot (not animate) the first frame after the fact I get the same error:

julia> n=1
1

julia> current_figure() # hide
Error showing value of type Figure:
ERROR: AssertionError: length(positions) == length(colors)
...

• are you running newest version (version from docs) ?
• can you reproduce the bug with a fresh environment ? (]activate --temp; add Makie)
• What platform + GPU are you on?: up-to-date Manjaro with kernel 6.1.31-2, Julia 1.9.1 (from pre-compiled binaries), but I can reproduce this in all machines I've tried

Here's the full error output:

ERROR: LoadError: AssertionError: length(positions) == length(colors)
Stacktrace:
  [1] draw_multi(primitive::Lines{Tuple{Vector{Point{2, Float32}}}}, ctx::Cairo.CairoContext, positions::Vector{Vec{2, Float32}}, colors::Vector{ColorTypes.RGBA{Float32}}, linewidths::Vector{Float32}, dash::Nothing)
    @ CairoMakie ~/.julia/packages/CairoMakie/zPic1/src/primitives.jl:165
  [2] draw_multi(primitive::Lines{Tuple{Vector{Point{2, Float32}}}}, ctx::Cairo.CairoContext, positions::Vector{Vec{2, Float32}}, colors::Vector{ColorTypes.RGBA{Float32}}, linewidth::Float32, dash::Nothing)
    @ CairoMakie ~/.julia/packages/CairoMakie/zPic1/src/primitives.jl:153
  [3] draw_atomic(scene::Scene, screen::CairoMakie.Screen{CairoMakie.IMAGE}, primitive::Union{LineSegments, Lines})
    @ CairoMakie ~/.julia/packages/CairoMakie/zPic1/src/primitives.jl:63
  [4] draw_plot(scene::Scene, screen::CairoMakie.Screen{CairoMakie.IMAGE}, primitive::Lines{Tuple{Vector{Point{2, Float32}}}})
    @ CairoMakie ~/.julia/packages/CairoMakie/zPic1/src/infrastructure.jl:108
  [5] draw_plot(scene::Scene, screen::CairoMakie.Screen{CairoMakie.IMAGE}, primitive::Combined{Makie.contour, Tuple{StepRangeLen{Float32, Float64, Float64, Int64}, StepRangeLen{Float32, Float64, Float64, Int64}, Matrix{Float32}}})
    @ CairoMakie ~/.julia/packages/CairoMakie/zPic1/src/infrastructure.jl:113
  [6] cairo_draw(screen::CairoMakie.Screen{CairoMakie.IMAGE}, scene::Scene)
    @ CairoMakie ~/.julia/packages/CairoMakie/zPic1/src/infrastructure.jl:49
  [7] colorbuffer(screen::CairoMakie.Screen{CairoMakie.IMAGE})
    @ CairoMakie ~/.julia/packages/CairoMakie/zPic1/src/screen.jl:307
  [8] colorbuffer(screen::CairoMakie.Screen{CairoMakie.IMAGE}, format::Makie.ImageStorageFormat)
    @ Makie ~/.julia/packages/Makie/iECbF/src/display.jl:355
  [9] recordframe!(io::VideoStream)
    @ Makie ~/.julia/packages/Makie/iECbF/src/ffmpeg-util.jl:242
 [10] Record(func::var"#5#6", figlike::Figure, iter::UnitRange{Int64}; kw_args::Base.Pairs{Symbol, Any, Tuple{Symbol, Symbol}, NamedTuple{(:format, :framerate), Tuple{SubString{String}, Int64}}})
    @ Makie ~/.julia/packages/Makie/iECbF/src/recording.jl:168
 [11] record(func::Function, figlike::Figure, path::String, iter::UnitRange{Int64}; kw_args::Base.Pairs{Symbol, Int64, Tuple{Symbol}, NamedTuple{(:framerate,), Tuple{Int64}}})
    @ Makie ~/.julia/packages/Makie/iECbF/src/recording.jl:148
 [12] top-level scope
    @ ~/repos/twake/tilted_ridge_simulations/mwe.jl:15
 [13] include(fname::String)
    @ Base.MainInclude ./client.jl:478
 [14] top-level scope
    @ REPL[1]:1
in expression starting at /home/tomas/repos/twake/tilted_ridge_simulations/mwe.jl:15

[aquirosr]

Are you sure it works fine with GLMakie? I tried it and even though it generates the video, the contours that it shows are wrong in my case except in the first frame.

[tomchor]

I hadn't visually checked the output of GLMakie but I guess you're right. Here's what I get for GLMakie with a heatmap as a background:

using GLMakie

fig = Figure()
n = Observable(1)

ax = Axis(fig[1, 1])

N = 10
A = randn(N, N, N)
Aₙ = @lift A[:,:,$n]
heatmap!(ax, Aₙ)
contour!(ax, Aₙ)

frames = 1:N

record(fig, "mwe.mp4", frames, framerate=4) do frame
    @info "Plotting frame $frame..."
    n[] = frame
end

mwe.mp4

So it looks like the contour output doesn't really align with heatmap and doesn't even change in time.

I'm gonna change the title. This seems like kind of a serious bug, I'm surprised that this isn't being reported by anyone else.

[tomchor]

@SimonDanisch are we missing something here? I'm thinking it's weird @aquirosr and I are the only reporting this bug, so maybe the issue is on our end?

[jkrumbiegel]

Probably an uncaught regression, maybe related to the addition of contour labels (at least I think it has worked before). We don't yet test updating of observables for all plot types, which is how this must have gone through.

[aquirosr]

I've been doing some tests and this worked up to v0.19.4, included.

[ffreyer]

GLMakie works fine for me on master. Maybe the heatmap is making it hard to see changes?

[tomchor]

I only plotted the heatmap to make it easier to see what contour should be doing. Here the output of the same script but without the underlying heatmap. Looks wrong to me:

mwe.mp4

This was also done on master. @ffreyer are you running the same MWE I posted above?

[SimonDanisch]

Yeah, this is a bug... The line plot observable in contour doesn't update on line updates anymore, it only reacts to label updates ;) Will push a fix shortly!