Partition layout for adjacency diagrams.

Creates icicle diagrams (rectangular) or sunburst diagrams (radial) where the area of each node is proportional to its value.

Unlike treemaps which show leaf nodes, partition layouts show the full hierarchy with each level getting equal vertical/radial space.

Examples

data = %{
  name: "root",
  children: [
    %{name: "A", value: 100},
    %{name: "B", children: [
      %{name: "B1", value: 50},
      %{name: "B2", value: 75}
    ]}
  ]
}

root = Visualize.Layout.Hierarchy.new(data)
  |> Visualize.Layout.Hierarchy.sum(fn d -> d[:value] || 0 end)

# Rectangular partition (icicle diagram)
partition = Visualize.Layout.Partition.new()
  |> Visualize.Layout.Partition.size([400, 300])

positioned = Visualize.Layout.Partition.generate(partition, root)
# Each node has x0, y0, x1, y1

# Radial partition (sunburst)
partition = Visualize.Layout.Partition.new()
  |> Visualize.Layout.Partition.size([2 * :math.pi(), 200])

positioned = Visualize.Layout.Partition.generate(partition, root)
# x0/x1 are angles, y0/y1 are radii