Makie: categorical x variables

HenriDeh · November 10, 2021, 2:45pm

Hi,

I recently moved from Plots to Makie and I am trying to make a box plot where each box aggregates data w.r.t. a real variable x.
However the three categories are not evenly spaced. You can see a MWE here which produces a pretty ugly plot.

julia> data = (y = rand(90), x = [fill(80,30); fill(320,30);  fill(1280,30)]);

julia> boxplot(data.x, data.y)

In Plots, I used to convert the x variables to strings so that it would treat them as categories.

julia> boxplot(string.(data.x), data.y)

This does not work in Makie. I checked the roadmap for Makie and nothing concerning such a problem seems to be planned. So I’m guessing there’s already a solution that I don’t know about.
Could anybody tell me how to get three evenly spaced boxes of the same width ?
I know that I could convert the x variables to 1 2 and 3 but 1) that’s annoying to do and 2) it would not give the correct x labels on this axis.

lazarusA · November 10, 2021, 4:17pm

In makie, now you only need to take care of the ticks positions. See this example with a lot of options to customise your plot:

github.com

lazarusA/100daysOfMakie/blob/main/src/boxplot.jl

using CairoMakie, Random, Distributions
Random.seed!(13)
n = 3000
colors = to_colormap(:spring, 8)[3:end]

set_theme!(theme_dark())
fig = Figure(resolution = (600, 400))
ax = Axis(fig[1,1]; palette = (; patchcolor = colors), 
    xticks = (1:7, ["cat 1", "A", "B", "C", "D", "E", "F"]), 
    yticks = ([-5], ["cat 2"]), yticklabelrotation = π/2)
boxplot!(ax, fill(-5,n), rand(Normal(0, 0.5), n); orientation=:horizontal, 
    whiskerwidth = 1, width = 2, color = (:orange, 0.95), 
    whiskercolor = :red, mediancolor = :yellow, markersize = 8, 
    strokecolor = :black, strokewidth = 1, label = "horizontal")
boxplot!(ax, fill(1,n), rand(Normal(1,  3), n); whiskerwidth = 1, 
    width = 0.5, color = :dodgerblue, whiskercolor = :dodgerblue, 
    mediancolor = :white, markersize = 5, strokecolor = :white, 
    strokewidth = 1, label = "vertical")
for i in 2:7
    boxplot!(ax, fill(i,n), rand(Normal(rand(-2:5), 2*rand() + 0.3), n);

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HenriDeh · November 10, 2021, 4:43pm

Okay so it seems that the way to go is to do multiple boxplot! calls instead of a single one.

Thanks for the example (and the other ones, I hope you’ll find the time to finish the 100 days of plotting )