Split Violin Plot

Mix.install([
  {:plotly_ex, "~> 0.3"},
  {:kino, "~> 0.18"}
])

Section

side: "positive" draws the KDE on the right side of the centre line only. side: "negative" draws only the left side. violinmode: "overlay" layers both traces on the same axis so the two halves form a single split violin for each category.

alias Plotly.{Figure, Violin}

:rand.seed(:exsss, {1, 2, 3})

gen = fn n, shift ->
  for _ <- 1..n do
    (for _ <- 1..12, do: :rand.uniform()) |> Enum.sum() |> Kernel.-(6.0 - shift)
  end
end

Figure.new()
|> Figure.add_trace(
  Violin.new(
    y: gen.(80, 0.0),
    name: "Male",
    side: "negative",
    line: %{color: "blue"},
    meanline: %{visible: true}
  )
)
|> Figure.add_trace(
  Violin.new(
    y: gen.(80, 0.5),
    name: "Female",
    side: "positive",
    line: %{color: "orchid"},
    meanline: %{visible: true}
  )
)
|> Figure.update_layout(
  title: "Split Violin Plot",
  violinmode: "overlay"
)
|> Plotly.show()