corner plot issue

[yebai]

The following example errors. It seems the issue is from upper stream packages instead of MCMCChains.

Note that the corner plot works fine when the number of variables is smaller than 3.

julia> val = rand(500, 4, 3);

julia> chn = Chains(val, [:a, :b, :c, :d]);

julia> corner(chn)


ERROR: The sum of widths must be 1!
Stacktrace:
  [1] error(s::String)
    @ Base ./error.jl:35
  [2] Plots.GridLayout(::Int64, ::Vararg{…}; parent::Plots.RootLayout, widths::Vector{…}, heights::Vector{…}, kw::@Kwargs{})
    @ Plots ~/.julia/packages/Plots/ju9dp/src/layouts.jl:232
  [3] grid(::Int64, ::Vararg{Int64}; kw::@Kwargs{widths::Vector{Float64}, heights::Vector{Float64}})
    @ Plots ~/.julia/packages/Plots/ju9dp/src/layouts.jl:209
  [4] macro expansion
    @ ~/.julia/packages/StatsPlots/cStOe/src/cornerplot.jl:29 [inlined]
  [5] apply_recipe(plotattributes::AbstractDict{Symbol, Any}, cp::StatsPlots.CornerPlot)
    @ StatsPlots ~/.julia/packages/RecipesBase/BRe07/src/RecipesBase.jl:300
  [6] _process_userrecipes!(plt::Any, plotattributes::Any, args::Any)
    @ RecipesPipeline ~/.julia/packages/RecipesPipeline/BGM3l/src/user_recipe.jl:38
  [7] recipe_pipeline!(plt::Any, plotattributes::Any, args::Any)
    @ RecipesPipeline ~/.julia/packages/RecipesPipeline/BGM3l/src/RecipesPipeline.jl:72
  [8] _plot!(plt::Plots.Plot, plotattributes::Any, args::Any)
    @ Plots ~/.julia/packages/Plots/ju9dp/src/plot.jl:223
  [9] #plot#188
    @ ~/.julia/packages/Plots/ju9dp/src/plot.jl:102 [inlined]
 [10] plot
    @ ~/.julia/packages/Plots/ju9dp/src/plot.jl:93 [inlined]
 [11] corner(args::Chains{Float64, AxisArrays.AxisArray{…}, Missing, @NamedTuple{…}, @NamedTuple{}})
    @ MCMCChains ~/.julia/packages/RecipesBase/BRe07/src/RecipesBase.jl:427
 [12] top-level scope
    @ REPL[53]:1
Some type information was truncated. Use `show(err)` to see complete types.