Gif plot fails with BoundsError

New to Julia
1

Hi,

I’m trying to run this simple example from the Plots library but it fails with BoundsError:

using Plots

plotlyjs()

# define the Lorenz attractor
mutable struct Lorenz
    dt; σ; ρ; β; x; y; z
end

function step!(l::Lorenz)
    dx = l.σ*(l.y - l.x)       ; l.x += l.dt * dx
    dy = l.x*(l.ρ - l.z) - l.y ; l.y += l.dt * dy
    dz = l.x*l.y - l.β*l.z     ; l.z += l.dt * dz
end

attractor = Lorenz((dt = 0.02, σ = 10., ρ = 28., β = 8//3, x = 1., y = 1., z = 1.)...)


# initialize a 3D plot with 1 empty series
plt = plot3d(1, xlim=(-25,25), ylim=(-25,25), zlim=(0,50),
                title = "Lorenz Attractor", marker = 2)

# build an animated gif by pushing new points to the plot, saving every 10th frame
@gif for i=1:1500
    step!(attractor)
    push!(plt, attractor.x, attractor.y, attractor.z)
end every 10

and output:

ERROR: LoadError: BoundsError: attempt to access 0-element Array{PlotlyBase.GenericTrace{Dict{Symbol,Any}},1} at index [1]
Stacktrace:
 [1] getindex at ./array.jl:729 [inlined]
 [2] #restyle!#125 at /home/milton/.julia/packages/PlotlyBase/4sp9a/src/api.jl:151 [inlined]
 [3] restyle!(::PlotlyBase.Plot{PlotlyBase.GenericTrace{Dict{Symbol,Any}}}, ::Int64, ::Dict{Symbol,Any}) at /home/milton/.julia/packages/PlotlyBase/4sp9a/src/api.jl:151
 [4] #restyle!#5(::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}, ::Function, ::PlotlyJS.SyncPlot, ::Int64, ::Dict{Symbol,Any}) at /home/milton/.julia/packages/PlotlyJS/CEJyh/src/display.jl:177
 [5] restyle! at /home/milton/.julia/packages/PlotlyJS/CEJyh/src/display.jl:177 [inlined]
 [6] _series_updated(::Plots.Plot{Plots.PlotlyJSBackend}, ::Plots.Series) at /home/milton/.julia/packages/Plots/47Tik/src/backends/plotlyjs.jl:32
 [7] setxyz!(::Plots.Plot{Plots.PlotlyJSBackend}, ::Tuple{Array{Float64,1},Array{Float64,1},Array{Float64,1}}, ::Int64) at /home/milton/.julia/packages/Plots/47Tik/src/utils.jl:877
 [8] push!(::Plots.Plot{Plots.PlotlyJSBackend}, ::Int64, ::Float64, ::Float64, ::Float64) at /home/milton/.julia/packages/Plots/47Tik/src/utils.jl:991
 [9] push!(::Plots.Plot{Plots.PlotlyJSBackend}, ::Float64, ::Float64, ::Float64) at /home/milton/.julia/packages/Plots/47Tik/src/utils.jl:956
 [10] macro expansion at /home/milton/Code/Random Stuff/tutorials/julia/lorenz.jl:26 [inlined]
 [11] top-level scope at /home/milton/.julia/packages/Plots/47Tik/src/animation.jl:163 [inlined]
 [12] top-level scope at ./none:0
 [13] include at ./boot.jl:326 [inlined]
 [14] include_relative(::Module, ::String) at ./loading.jl:1038
 [15] include(::Module, ::String) at ./sysimg.jl:29
 [16] include(::String) at ./client.jl:403
 [17] top-level scope at none:0
in expression starting at /home/milton/Code/Random Stuff/tutorials/julia/lorenz.jl:24

I don’t know what is the problem. I am new to Julia and I was expecting this to work as is (since it’s an example).

2

Looks like an issue with the plotlyjs backend. What happens if you run the code without that call (which is not part of the example)?

1 Like
3

The reason I was using plotly is that when I use the default (I think its gr), I got this error:

/home/milton/.julia/packages/GR/KGODl/src/../deps/gr/bin/gksqt: error while loading shared libraries: libQt5Widgets.so.5: cannot open shared object file: No such file or directory
connect: Connection refused
GKS: can't connect to GKS socket application
Did you start 'gksqt'?

I found this issue on the Plots page:

https://github.com/JuliaPlots/Plots.jl/issues/1649

I now managed to solve it by installing the qt5widgets library. Still, seems like a weird issue with the plotlyjs library. Should it be reported to them?

Thanks for the help by the way.

4

It’s probably an issue with Plots’ plotlyjs backend. It would be helpful if you could open an issue on Plots, also reporting your ]status of Plots and PlotlyJS and your versioninfo(). Thanks!

5

Okay, opened a new issue referencing error 489 which is similar but on windows and using a previous version of Julia.