Normalized Histogram

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

Section

histnorm normalises the y-axis:

• "" (default) — raw counts
• "probability" — each bar is count / total (sums to 1)
• "percent" — each bar is (count / total) × 100 (sums to 100)
• "density" — count / (bin width × total) — useful for comparing distributions of different sizes
• "probability density" — density that integrates to 1

alias Plotly.{Figure, Histogram}

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

x = for _ <- 1..500 do
  (for _ <- 1..12, do: :rand.uniform()) |> Enum.sum() |> Kernel.-(6.0)
end

for norm <- ["", "probability", "percent", "density"] do
  label = if norm == "", do: "count (default)", else: norm

  Figure.new()
  |> Figure.add_trace(Histogram.new(x: x, histnorm: (if norm == "", do: nil, else: norm)))
  |> Figure.update_layout(title: "histnorm: \"#{label}\"")
  |> Plotly.show()
end
|> Kino.Layout.grid(columns: 2)