Uncertainty ribbon plot

docs/src/examples.md

@@ -607,3 +607,15 @@ julia> plot(sin, [x ± 0.1 for x in 1:0.2:10], size = (1200, 800))
 ```
 
 ![image](plot-example.png)
+
+Displaying errors as a ribbon plot is also supported, but only for the y-axis uncertainty (a limitation inherited from `Plots.jl` due to how `ribbon` implements a `fillrange`).
+
+```julia
+julia> x = range(0, 6, 301)
+
+julia> y = measurement.(cospi.(x), (5 .+ 2sinpi.(5x))/10)
+
+julia> plot(x, y, uncertainty_plot = :ribbon, color = :red)
+```
+
+![image](plot-example-ribbon.png)

ext/MeasurementsRecipesBaseExt.jl

@@ -24,8 +24,21 @@ else
     using ..RecipesBase
 end
 
-@recipe function f(y::AbstractArray{<:Measurement})
-    yerror := uncertainty.(y)
+unrecognised_uncertainty_plot_message = """
+    Unrecognized value for `uncertainty_plot` keyword.
+    Expecting either of `:bar` (default), `:ribbon`, or `:none`.
+    """
+
+@recipe function f(y::AbstractArray{<:Measurement}; uncertainty_plot = :bar)
+	if uncertainty_plot == :ribbon
+		ribbon := uncertainty.(y)
+	elseif uncertainty_plot == :bar
+		yerror := uncertainty.(y)
+    elseif uncertainty_plot == :none
+
+	else
+		error(unrecognised_uncertainty_plot_message)
+	end
     value.(y)
 end
 
@@ -47,9 +60,17 @@ end
     value.(x), y
 end
 
-@recipe function f(x::AbstractArray, y::AbstractArray{<:Measurement})
-    yerror := uncertainty.(y)
-    x, value.(y)
+@recipe function f(x::AbstractArray, y::AbstractArray{<:Measurement}; uncertainty_plot = :bar)
+	if uncertainty_plot == :ribbon
+		ribbon := uncertainty.(y)
+	elseif uncertainty_plot == :bar
+		yerror := uncertainty.(y)
+    elseif uncertainty_plot == :none
+
+	else
+		error(unrecognised_uncertainty_plot_message)
+	end
+	x, value.(y)
 end
 
 end

test/plots.jl

@@ -25,3 +25,11 @@ rec = RecipesBase.apply_recipe(Dict{Symbol, Any}(), x, value.(y))
 rec = RecipesBase.apply_recipe(Dict{Symbol, Any}(), value.(x), y)
 @test getfield(rec[1], 1) == Dict{Symbol, Any}(:yerror => uncertainty.(y))
 @test rec[1].args == (value.(x), value.(y))
+
+rec = RecipesBase.apply_recipe(Dict{Symbol, Any}(), value.(y); uncertainty_plot = :ribbon)
+@test getfield(rec[1], 1) == Dict{Symbol, Any}(:ribbon => uncertainty.(y))
+@test rec[1].args == (value.(x), value.(y))
+
+rec = RecipesBase.apply_recipe(Dict{Symbol, Any}(), x, value.(y); uncertainty_plot = :ribbon)
+@test getfield(rec[1], 1) == Dict{Symbol, Any}(:ribbon => uncertainty.(y))
+@test rec[1].args == (value.(x), value.(y))