2D density plots (#80)

docs/src/api.md

@@ -50,6 +50,15 @@ ridgeplot
 ridgeplot(boot)
 ```
 
+## Ridge 2D Plots
+
+```@docs
+ridge2d
+```
+
+```@example Coefplot
+ridge2d(boot)
+```
 
 ## Random effects and group-level predictions
 

src/MixedModelsMakie.jl

@@ -24,6 +24,8 @@ export RanefInfo,
        qqcaterpillar!,
        ranefinfo,
        ranefinfotable,
+       ridge2d,
+       ridge2d!,
        ridgeplot,
        ridgeplot!,
        shrinkageplot,
@@ -40,6 +42,7 @@ include("caterpillar.jl")
 include("coefplot.jl")
 include("profile.jl")
 include("ridge.jl")
+include("ridge2d.jl")
 include("xyplot.jl")
 include("recipes.jl")
 

src/ridge2d.jl

@@ -0,0 +1,40 @@
+function _ridge2d_panel!(ax::Axis, i::Int, j::Int, cnames::Vector{Symbol}, tbl)
+    x = Tables.getcolumn(tbl, cnames[j])
+    y = Tables.getcolumn(tbl, cnames[i])
+    dens = kde((x, y))
+    scatter!(ax, x, y; color=:black, alpha=0.2)
+    plt = contour!(ax, collect(dens.x), collect(dens.y), dens.density;
+                   color=:green, linewidth=3,
+                   labelsize=30, labels=false)   # reference points
+
+    return plt
+end
+
+"""
+    ridge2d!(f::Union{Makie.FigureLike,Makie.GridLayout}, bs::MixedModelBootstrap; 
+             ptype=:β)
+
+Plot pairwise bivariate scatter plots with overlain densities for a bootstrap sample.
+
+
+`ptype` specifies the set of parameters to examine, e.g. `:β`, `:σ`, `:ρ`.
+"""
+function ridge2d!(f::Union{Makie.FigureLike,Makie.GridLayout}, bs::MixedModelBootstrap;
+                  ptype=:β)
+    tbl = bs.tbl
+    cnames = [string(x) for x in propertynames(tbl)[2:end]]
+    filter!(startswith(string(ptype)), cnames)
+    isempty(cnames) &&
+        throw(ArgumentError("No parameters $ptype found."))
+    length(cnames) == 1 &&
+        throw(ArgumentError("Only 1 $ptype-paramater found: 2D plots require at least 2."))
+    splomaxes!(f, cnames, _ridge2d_panel!, Symbol.(cnames), tbl)
+    return f
+end
+
+"""$(@doc ridge2d!)"""
+function ridge2d(bs::MixedModelBootstrap, args...; kwargs...)
+    f = Figure(; resolution=(1000, 1000)) # use an aspect ratio of 1 for the whole figure
+
+    return ridge2d!(f, bs, args...; kwargs...)
+end

test/runtests.jl

@@ -36,8 +36,8 @@ m2 = fit(MixedModel,
                              (1 + spkr | item)),
          MixedModels.dataset(:kb07); progress)
 
-b1 = parametricbootstrap(MersenneTwister(42), 100, m1; hide_progress=!progress)
-
+b1 = parametricbootstrap(MersenneTwister(42), 500, m1; progress,
+                         optsum_overrides=(; ftol_rel=1e-6))
 g1 = fit(MixedModel,
          @formula(r2 ~ 1 + anger + gender + btype + situ +
                        (1 | subj) + (1 + gender | item)),
@@ -141,6 +141,15 @@ end
     save(joinpath(OUTDIR, "ridge_sleepstudy.png"), f)
 end
 
+@testset "ridge2d" begin
+    @test_throws(ArgumentError("No parameters x found."),
+                 ridge2d(b1; ptype=:x))
+    @test_throws(ArgumentError("Only 1 ρ-paramater found: 2D plots require at least 2."),
+                 ridge2d(b1; ptype=:ρ))
+    save(joinpath(OUTDIR, "ridge2d_beta.png"), ridge2d(b1))
+    save(joinpath(OUTDIR, "ridge2d_sigma.png"), ridge2d(b1; ptype=:σ))
+end
+
 @testset "shrinkageplot" begin
     f = shrinkageplot(m1)
     save(joinpath(OUTDIR, "shrinkage_sleepstudy.png"), f)