Grouped Violin Plot

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

Section

Multiple Violin traces with the same categorical x: values group side-by-side. layout.violinmode: "group" places them next to each other (default is "overlay").

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.(50, 0.0) ++ gen.(50, 0.0),
    x: List.duplicate("Mon", 50) ++ List.duplicate("Tue", 50),
    name: "Group A",
    box: %{visible: true},
    meanline: %{visible: true}
  )
)
|> Figure.add_trace(
  Violin.new(
    y: gen.(50, 1.0) ++ gen.(50, 1.0),
    x: List.duplicate("Mon", 50) ++ List.duplicate("Tue", 50),
    name: "Group B",
    box: %{visible: true},
    meanline: %{visible: true}
  )
)
|> Figure.update_layout(
  title: "Grouped Violin Plot",
  violinmode: "group"
)
|> Plotly.show()