violin plot: airquality data

using CairoMakie, RDatasets, Colors, ColorSchemes

airquality = dataset("datasets", "airquality")
categories = ["Ozone", "Solar.R", "Wind", "Temp"]
colors = categorical_colors(:Set1, length(categories))

fig = Figure(size = (600, 400))
ax = Axis(fig[1, 1], xticks = (1:length(categories), categories))
for (indx, f) in enumerate(categories)
    datam = filter(x -> x !== missing, airquality[:, f])
    a = fill(indx, length(datam))
    violin!(ax, a, datam; width = 0.35, color = (colors[indx], 0.45),
        strokecolor = colors[indx], show_median = true, mediancolor = :black)
end
fig