flip (#3732)

* flip

* docs, changelog

* pr link

* in-place

* update docstring

* add refimg test

* allow vector label_offsets and consider offset in label positions

* test combinations of attributes

* update test name

---------

Co-authored-by: ffreyer <frederic481994@hotmail.de>

CHANGELOG.md

@@ -9,6 +9,7 @@
 - Added `scale` attribute to `violin` [#3352](https://github.com/MakieOrg/Makie.jl/pull/3352).
 - Use label formatter in barplot [#3718](https://github.com/MakieOrg/Makie.jl/pull/3718).
 - Fix the incorrect shading with non uniform markerscale in meshscatter [#3722](https://github.com/MakieOrg/Makie.jl/pull/3722)
+- Add `scale_to=:flip` option to `hist`, which flips the direction of the bars [#3732](https://github.com/MakieOrg/Makie.jl/pull/3732)
 - Fixed an issue with the texture atlas not updating in WGLMakie after display, causing new symbols to not show up [#3737](https://github.com/MakieOrg/Makie.jl/pull/3737)
 
 ## [0.20.8] - 2024-02-22

ReferenceTests/src/tests/examples2d.jl

@@ -1068,6 +1068,40 @@ end
     f
 end
 
+@reference_test "Histogram" begin
+    data = sin.(1:1000)
+
+    fig = Figure(size = (900, 900))
+    hist(fig[1, 1], data)
+    hist(fig[1, 2], data, bins = 30, color = :orange)
+    a, p = hist(fig[1, 3], data, bins = 10, color = :transparent, strokecolor = :red, strokewidth = 4.0)
+    a.xgridcolor[] = RGBAf(0,0,0,1); a.ygridcolor[] = RGBAf(0,0,0,1)
+
+    hist(fig[2, 1], data, normalization = :pdf, direction = :x)
+    hist(fig[2, 2], data, normalization = :density, color = 1:15)
+    hist(fig[2, 3], data, normalization = :probability, scale_to = :flip)
+
+    hist(fig[3, 1], data, offset = 20.0)
+    hlines!(0.0, color = :black, linewidth = 3)
+    hist(fig[3, 2], data, fillto = 1.0, scale_to = -5.0, direction = :x)
+    vlines!(0.0, color = :black, linewidth = 3)
+    hist(fig[3, 3], data, bar_labels = :y, label_size = 10, bins = 10)
+
+    hist(
+        fig[4, 1], data, scale_to = :flip, offset = 20,
+        bar_labels = :x, label_size = 12, label_color = :green
+    )
+    hlines!(0.0, color = :black, linewidth = 3)
+    i12 = mod1.(1:10, 2)
+    hist(fig[4, 2], data, scale_to = :flip, bins = 10, direction = :x,
+        bar_labels = :x, label_size = [14, 10][i12],
+        label_color = [:yellow, :blue][i12], label_offset = [-30, 10][i12]
+    )
+    hist(fig[4, 3], data, weights = 1.0 ./ (2.0 .+ data))
+
+    fig
+end
+
 @reference_test "Stephist" begin
     stephist(RNG.rand(10000))
     current_figure()
@@ -1406,7 +1440,7 @@ end
 end
 
 @reference_test "Violin plots differently scaled" begin
-    fig = Figure() 
+    fig = Figure()
     xs = vcat([fill(i, i * 1000) for i in 1:4]...)
     ys = vcat(RNG.randn(6000), RNG.randn(4000) * 2)
     for (i, scale) in enumerate([:area, :count, :width])

docs/reference/plots/hist.md

@@ -41,7 +41,8 @@ hist(data, normalization = :pdf, bar_labels = :values,
 
 With `scale_to`, and `offset`, one can put multiple histograms into the same plot.
 Note, that offset automatically sets fillto, to move the whole barplot.
-Also, one can use a negative `scale_to` amount to flip the histogram.
+Also, one can use a negative `scale_to` amount to flip the histogram,
+or `scale_to=:flip` to flip the direction of the bars without changing their height.
 
 \begin{examplefigure}{}
 ```julia

src/basic_recipes/barplot.jl

@@ -198,18 +198,18 @@ function text_attributes(values, in_y_direction, flip_labels_at, color_over_back
 
         if isflipped
             # plot text inside bar
-            push!(offsets, swap(0, -label_offset))
+            push!(offsets, swap(0, -sv_getindex(label_offset, i)))
             push!(text_colors, geti(color_over_bar, i))
         else
             # plot text next to bar
-            push!(offsets, swap(0, label_offset))
+            push!(offsets, swap(0, sv_getindex(label_offset, i)))
             push!(text_colors, geti(color_over_background, i))
         end
     end
     return aligns, offsets, text_colors
 end
 
-function barplot_labels(xpositions, ypositions, bar_labels, in_y_direction, flip_labels_at,
+function barplot_labels(xpositions, ypositions, offset, bar_labels, in_y_direction, flip_labels_at,
                         color_over_background, color_over_bar, label_formatter, label_offset, label_rotation,
                         label_align)
     if bar_labels isa Symbol && bar_labels in (:x, :y)
@@ -225,8 +225,8 @@ function barplot_labels(xpositions, ypositions, bar_labels, in_y_direction, flip
         if length(bar_labels) == length(xpositions)
             attributes = text_attributes(ypositions, in_y_direction, flip_labels_at, color_over_background,
                                          color_over_bar, label_offset, label_rotation, label_align)
-            label_pos = map(xpositions, ypositions, bar_labels) do x, y, l
-                return (string(label_formatter(l)), in_y_direction ? Point2f(x, y) : Point2f(y, x))
+            label_pos = broadcast(xpositions, ypositions, offset, bar_labels) do x, y, off, l
+                return (string(label_formatter(l)), in_y_direction ? Point2f(x, y+off) : Point2f(y, x+off))
             end
             return (label_pos, attributes...)
         else
@@ -296,7 +296,7 @@ function Makie.plot!(p::BarPlot)
         if !isnothing(bar_labels)
             oback = color_over_background === automatic ? label_color : color_over_background
             obar = color_over_bar === automatic ? label_color : color_over_bar
-            label_args = barplot_labels(x̂, y, bar_labels, in_y_direction,
+            label_args = barplot_labels(x̂, y, offset, bar_labels, in_y_direction,
                                         flip_labels_at, to_color(oback), to_color(obar),
                                         label_formatter, label_offset, label_rotation, label_align)
             labels[], label_aligns[], label_offsets[], label_colors[] = label_args

src/stats/hist.jl

@@ -13,7 +13,9 @@ function _hist_center_weights(values, edges, normalization, scale_to, wgts)
     h_norm = StatsBase.normalize(h; mode = normalization)
     weights = h_norm.weights
     centers = edges[1:end-1] .+ (diff(edges) ./ 2)
-    if !isnothing(scale_to)
+    if scale_to === :flip
+        weights .= -weights
+    elseif !isnothing(scale_to)
         max = maximum(weights)
         weights .= weights ./ max .* scale_to
     end
@@ -106,14 +108,18 @@ The following attributes can move the histogram around,
 which comes in handy when placing multiple histograms into one plot:
 * `offset = 0.0`: adds an offset to every value
 * `fillto = 0.0`: defines where the bar starts
-* `scale_to = nothing`: allows to scale all values to a certain height
-* `flip = false`: flips all values
+* `scale_to = nothing`: allows to scale all values to a certain height. This
+can also be set to `:flip` to flip the direction of histogram bars without
+scaling them to a common height.
 
 Color can either be:
 * a vector of `bins` colors
 * a single color
 * `:values`, to color the bars with the values from the histogram
 
+You can also draw a histogram in x-direction rather than y-direction by setting
+`direction = :x`.
+
 ## Attributes
 $(ATTRIBUTES)
 """