Workaround to use stackedhist! with Makie logscale

Project.toml

@@ -1,14 +1,15 @@
 name = "FHist"
 uuid = "68837c9b-b678-4cd5-9925-8a54edc8f695"
-authors = ["Moelf <proton[at]jling.dev>", "Nick Amin <amin.nj[at]gmail.com>"]
 version = "0.11.17"
+authors = ["Moelf <proton[at]jling.dev>", "Nick Amin <amin.nj[at]gmail.com>"]
 
 [deps]
 BayesHistogram = "000d9b38-65fe-4c81-bdb9-69f01f102479"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 Measurements = "eff96d63-e80a-5855-80a2-b1b0885c5ab7"
 Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 StatsBase = "2913bbd2-ae8a-5f71-8c99-4fb6c76f3a91"
+StructArrays = "09ab397b-f2b6-538f-b94a-2f83cf4a842a"
 
 [weakdeps]
 CairoMakie = "13f3f980-e62b-5c42-98c6-ff1f3baf88f0"
@@ -34,17 +35,18 @@ Plots = "1.40"
 RecipesBase = "^1"
 Statistics = "1"
 StatsBase = "^0.33, 0.34"
+StructArrays = "0.7.2"
 Test = "1"
 julia = "^1.10"
 
 [extras]
+Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
 CairoMakie = "13f3f980-e62b-5c42-98c6-ff1f3baf88f0"
 HDF5 = "f67ccb44-e63f-5c2f-98bd-6dc0ccc4ba2f"
 Makie = "ee78f7c6-11fb-53f2-987a-cfe4a2b5a57a"
 Plots = "91a5bcdd-55d7-5caf-9e0b-520d859cae80"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
-Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
 
 [targets]
-test = ["Test", "HDF5", "Aqua"]
 docs = ["Test", "HDF5", "CairoMakie", "Plots"]
+test = ["Test", "HDF5", "Aqua"]

ext/FHistMakieExt.jl

@@ -1,6 +1,7 @@
 module FHistMakieExt
 using FHist, FHist.Measurements
 using Statistics
+using StructArrays
 isdefined(Base, :get_extension) ? (using Makie) : (using ..Makie)
 
 import FHist: stackedhist, stackedhist!
@@ -81,10 +82,66 @@ fig
         color=Makie.wong_colors(),
         labels=nothing,
         whiskerwidth=10,
-        gap=-0.01
+        gap=-0.01,
+        direction=:y
     )
 end
 
+function _smart_log_clamp(ys, ref=ys)
+    # x-scale log and !(in_y_direction) is equiavlent to y-scale log in_y_direction
+    # use the minimal non-zero y divided by 2 as lower bound for log scale
+    smart_fillto = minimum(y -> y<=0 ? oftype(y, Inf) : y, ref) / 2
+    return clamp.(ys, smart_fillto, Inf), smart_fillto
+end
+
+
+function stack_from_to_sorted(y)
+    to = cumsum(y)
+    from = [0.0; to[firstindex(to):end-1]]
+
+    (from = from, to = to)
+end
+
+function stack_from_to(i_stack, y)
+    # save current order
+    order = 1:length(y)
+    # sort by i_stack
+    perm = sortperm(i_stack)
+    # restore original order
+    inv_perm = sortperm(order[perm])
+
+    from, to = stack_from_to_sorted(view(y, perm))
+
+    (from = view(from, inv_perm), to = view(to, inv_perm))
+end
+
+function stack_grouped_from_to(i_stack, y, grp; log_clamp=false)
+    from = Array{Float64}(undef, length(y))
+    to   = Array{Float64}(undef, length(y))
+
+    groupby = StructArray((; grp...))
+    grps = StructArrays.finduniquesorted(groupby)
+    last_pos = map(grps) do (g, inds)
+        g => any(y[inds] .> 0) || all(y[inds] .== 0)
+    end |> Dict
+    is_pos = map(y, groupby) do v, g
+        last_pos[g] = iszero(v) ? last_pos[g] : v > 0
+    end
+
+    groupby = StructArray((; grp..., is_pos))
+    grps = StructArrays.finduniquesorted(groupby)
+    for (grp, inds) in grps
+        fromto = stack_from_to(i_stack[inds], y[inds])
+        from[inds] .= fromto.from
+        to[inds] .= fromto.to
+    end
+
+    if log_clamp
+        from, _ = _smart_log_clamp(from, to)
+    end
+    (from = from, to = to)
+end
+
 function Makie.plot!(input::StackedHist{<:Tuple{AbstractVector{<:Hist1D}}})
     hs = input[1][]
     Nhist = length(hs)
@@ -100,12 +157,29 @@ function Makie.plot!(input::StackedHist{<:Tuple{AbstractVector{<:Hist1D}}})
     totals = Measurements.value.(mes)
     errs = Measurements.uncertainty.(mes)
 
+    dir = input.direction[]
+    in_y_direction = get((y=true, x=false), dir) do
+        error("Invalid direction $dir. Options are :x and :y.")
+    end
+
+    transformation = input.transformation.transform_func[]
+    _logT = Union{typeof(log), typeof(log2), typeof(log10), Base.Fix1{typeof(log), <: Real}}
+    log_clamp = transformation isa Tuple && in_y_direction&& transformation[2] isa _logT || (!in_y_direction && transformation[1] isa _logT)
+
+    if log_clamp
+        ys, fillto = _smart_log_clamp(ys)
+    end
+
+    if length(hs) > 1
+        ys, fillto = stack_grouped_from_to(grp, ys, (x=xs,); log_clamp)
+    end
+
     c = input[:color][]
     length(c) < Nhist && throw("provided $(length(c)) colors, not enough for $Nhist histograms")
     Makie.barplot!(input, xs, ys;
-        stack=grp,
         color=c[grp],
         gap=input[:gap],
+        fillto
     )
 
     error_color = input[:error_color]