stat_dodge

docs/src/gallery/geometries.md

@@ -50,6 +50,36 @@ hstack(p1, p2a, p2b)
 
 See [`Scale.color_discrete_manual`](@ref) for more information.
 
+## [`Geom.barerror`](@ref)
+
+```@example
+using Compose, DataFrames, Gadfly, RDatasets, Statistics
+set_default_plot_size(21cm, 8cm)
+salaries = dataset("car","Salaries")
+salaries.Salary /= 1000.0
+salaries.Discipline = ["Discipline $(x)" for x in salaries.Discipline]
+df = by(salaries, [:Rank,:Discipline], :Salary=>mean, :Salary=>std)
+[df[i] = df.Salary_mean.+j*df.Salary_std for (i,j) in zip([:ymin, :ymax], [-1, 1.0])]
+df[:label] = string.(round.(Int, df.Salary_mean))
+
+p1 = plot(df, x=:Discipline, y=:Salary_mean, color=:Rank, 
+    Scale.x_discrete(levels=["Discipline A", "Discipline B"]),
+    ymin=:ymin, ymax=:ymax, Geom.barerror,
+    Geom.bar(position=:dodge), 
+    Scale.color_discrete(levels=["Prof", "AssocProf", "AsstProf"]),
+    Guide.colorkey(title="", pos=[0.76w, -0.38h]),
+    Theme(bar_spacing=0mm, stroke_color=c->"black")
+)
+p2 = plot(df, y=:Discipline, x=:Salary_mean, color=:Rank, 
+    Coord.cartesian(yflip=true), Scale.y_discrete,
+    xmin=:ymin, xmax=:ymax, Geom.barerror(axis=:y),
+    Geom.bar(position=:dodge, orientation=:horizontal), 
+    Scale.color_discrete(levels=["Prof", "AssocProf", "AsstProf"]),
+    Guide.yticks(orientation=:vertical), Guide.ylabel(nothing),
+    Theme(bar_spacing=0mm, stroke_color=c->"gray")
+)
+hstack(p1,p2)
+```
 
 ## [`Geom.beeswarm`](@ref)
 

docs/src/gallery/statistics.md

@@ -35,6 +35,33 @@ p2 = plot(vcat(Db...), x=:x, color=:u,
 hstack(p1,p2)
 ```
 
+## [`Stat.dodge`](@ref)
+
+```@example
+using DataFrames, Gadfly, RDatasets, Statistics
+set_default_plot_size(21cm, 8cm)
+salaries = dataset("car","Salaries")
+salaries.Salary /= 1000.0
+salaries.Discipline = ["Discipline $(x)" for x in salaries.Discipline]
+df = by(salaries, [:Rank,:Discipline], :Salary=>mean, :Salary=>std)
+[df[i] = df.Salary_mean.+j*df.Salary_std for (i,j) in zip([:ymin, :ymax], [-1, 1.0])]
+df[:label] = string.(round.(Int, df.Salary_mean))
+
+p1 = plot(df, x=:Discipline, y=:Salary_mean, color=:Rank, 
+    Scale.x_discrete(levels=["Discipline A", "Discipline B"]),
+    label=:label, Geom.label(position=:centered), Stat.dodge(position=:stack),
+    Geom.bar(position=:stack)
+)
+p2 = plot(df, y=:Discipline, x=:Salary_mean, color=:Rank, 
+    Coord.cartesian(yflip=true), Scale.y_discrete,
+    label=:label, Geom.label(position=:right), Stat.dodge(axis=:y),
+    Geom.bar(position=:dodge, orientation=:horizontal), 
+    Scale.color_discrete(levels=["Prof", "AssocProf", "AsstProf"]),
+    Guide.yticks(orientation=:vertical), Guide.ylabel(nothing)
+)
+hstack(p1, p2)
+```
+
 ## [`Stat.qq`](@ref)
 
 ```@example

src/geom/bar.jl

@@ -170,7 +170,7 @@ function render_dodged_bar(geom::BarGeometry,
                                     orientation::Symbol)
     # preserve factor orders of pooled data arrays
     if isa(aes.color, IndirectArray)
-        idxs = sortperm(aes.color.index, rev=true)
+        idxs = sortperm(aes.color.index, rev=false)
     else
         idxs = 1:length(aes.color)
     end

src/geom/errorbar.jl

@@ -1,7 +1,9 @@
 struct ErrorBarGeometry <: Gadfly.GeometryElement
+    default_statistic::Gadfly.StatisticElement
     tag::Symbol
 end
-ErrorBarGeometry(; tag=empty_tag) = ErrorBarGeometry(tag)
+ErrorBarGeometry(default_statistic=Gadfly.Stat.identity(); tag=empty_tag) = 
+    ErrorBarGeometry(default_statistic, tag)
 
 
 struct XErrorBarGeometry <: Gadfly.GeometryElement
@@ -42,9 +44,22 @@ color them with `color`.
 """
 const yerrorbar = YErrorBarGeometry
 
+
+"""
+    Geom.barerror(;position=:dodge, axis=:x)  
+
+Draw barplot errorbars at `xmin` to `xmax` or `ymin` to `ymax`. Optionally color them with `color`.
+Particularly for use with dodged bar plots.  This geometry is equivalent to [`Geom.errorbar`](@ref) with [`Stat.dodge`](@ref).
+See the latter for more information.
+"""
+barerror(; position::Symbol=:dodge, axis::Symbol=:x) =  ErrorBarGeometry(Stat.dodge(position=position, axis=axis))
+
+
 element_aesthetics(::ErrorBarGeometry) = [:x, :y, :xmin, :xmax, :ymin, :ymax]
 element_aesthetics(::XErrorBarGeometry) = [:y, :xmin, :xmax]
 element_aesthetics(::YErrorBarGeometry) = [:x, :ymin, :ymax]
+default_statistic(geom::ErrorBarGeometry) = geom.default_statistic
+
 
 # Generate a form for the errorbar geometry.
 #

src/statistics.jl

@@ -2019,6 +2019,57 @@ function apply_statistic(stat::EllipseStatistic,
     aes.y = ellipse_y
     linestyle_scale = get(scales, :linestyle, Scale.linestyle_discrete())
     Scale.apply_scale(linestyle_scale, [aes], Gadfly.Data(linestyle = aes.linestyle))
+end
+
+
+struct DodgeStatistic <: Gadfly.StatisticElement
+    position::Symbol
+    axis::Symbol
+end
+DodgeStatistic(; position::Symbol=:dodge, axis::Symbol=:x) = DodgeStatistic(position, axis)
+
+input_aesthetics(stat::DodgeStatistic) = [:x, :y]
+output_aesthetics(stat::DodgeStatistic) = [:x, :y]
+default_scales(stat::DodgeStatistic) = [Gadfly.Scale.x_continuous(), Gadfly.Scale.y_continuous()]
+
+"""
+    Stat.dodge[(; position=:dodge, axis=:x)]
+
+Transform the points in $(aes2str(input_aesthetics(dodge()))) into set of dodged or stacked points
+ in $(aes2str(output_aesthetics(dodge()))).  `position` is `:dodge` or `:stack`.
+`axis` is `:x` or `:y`. Used by [`Geom.barerror`](@ref Gadfly.Geom.barerror).
+"""
+const dodge = DodgeStatistic
+
+
+function apply_statistic(stat::DodgeStatistic,
+                            scales::Dict{Symbol, Gadfly.ScaleElement},
+                            coord::Gadfly.CoordinateElement,
+                            aes::Gadfly.Aesthetics)
+
+    othervar = (stat.axis == :x) ? :y : :x
+    vals = getfield(aes, stat.axis)
+    nbars = length(unique(aes.color))
+
+    if stat.position==:dodge
+        offset = range(-0.5+0.5/nbars, 0.5, step=1/nbars)
+        dodge = getindex(offset, aes.color.index)
+        setfield!(aes, stat.axis, vals.+dodge)
+    elseif stat.position==:stack
+        ovals = getfield(aes, othervar)
+        idxs = isa(aes.color, IndirectArray) ? sortperm(aes.color.index, rev=true) : 1:length(aes.color)
+        idxs2 = sortperm(idxs)
+        m1 = reshape(idxs, :, nbars)
+        m2 = cumsum(ovals[m1], dims=2) .- 0.5*ovals[m1]    
+        setfield!(aes, othervar, m2[idxs2])
+    else
+        error("position can be :dodge (default) or :stack")
     end
+end
+
+
+
+
+
 
 end # module Stat

test/testscripts/stat_dodge.jl

@@ -0,0 +1,25 @@
+using Compose, DataFrames, Gadfly, RDatasets, Statistics
+set_default_plot_size(21cm, 8cm)
+
+salaries = dataset("car","Salaries")
+salaries.Salary /= 1000.0
+salaries.Discipline = ["Discipline $(x)" for x in salaries.Discipline]
+df = by(salaries, [:Rank,:Discipline], :Salary=>mean, :Salary=>std)
+[df[i] = df.Salary_mean.+j*df.Salary_std for (i,j) in zip([:ymin, :ymax], [-1, 1.0])]
+df[:label] = string.(round.(Int, df.Salary_mean))
+
+p1 = plot(df, x=:Discipline, y=:Salary_mean, color=:Rank, 
+Scale.x_discrete(levels=["Discipline A", "Discipline B"]),
+ymin=:ymin, ymax=:ymax, Geom.barerror,
+Geom.bar(position=:dodge), 
+Scale.color_discrete(levels=["Prof", "AssocProf", "AsstProf"]),
+Guide.colorkey(title="", pos=[0.76w, -0.38h]),
+Theme(bar_spacing=0mm, stroke_color=c->"black")
+)
+p2 = plot(df, x=:Salary_mean, y=:Discipline, color=:Rank, 
+    Scale.y_discrete(levels=["Discipline A", "Discipline B"]),
+    label=:label, Geom.label(position=:centered), Stat.dodge(position=:stack, axis=:y),
+    Geom.bar(position=:stack, orientation=:horizontal),
+    Guide.yticks(orientation=:vertical), Guide.ylabel(nothing)
+)
+hstack(p1, p2)