Tree layout algorithm for hierarchical node-link diagrams.
Implements the Reingold–Tilford "tidy" algorithm as refined by Buchheim, Jünger and
Leipert (linear time, threads and accumulated shifts), ported from d3-hierarchy's
tree: children of one parent are placed left to right with the gap given by
separation, every parent is centred over its children, and subtrees are shifted so
that nodes at the same depth never overlap while adjacent subtrees keep their
separation.
Examples
# Create hierarchy
data = %{
name: "root",
children: [
%{name: "A", children: [%{name: "A1"}, %{name: "A2"}]},
%{name: "B"}
]
}
root = Visualize.Layout.Hierarchy.new(data)
# Apply tree layout
tree = Visualize.Layout.Tree.new()
|> Visualize.Layout.Tree.size([400, 200])
positioned = Visualize.Layout.Tree.generate(tree, root)
# Each node now has x, y coordinates
Visualize.Layout.Hierarchy.each(positioned, fn node ->
IO.puts("#{node.data.name}: (#{node.x}, #{node.y})")
end)Summary
Functions
Generates the tree layout, positioning all nodes.
Creates a new tree layout
Sets the fixed node size.
Sets the separation function between nodes.
Sets the size of the layout.
Types
@type t() :: %Visualize.Layout.Tree{ node_size: {number(), number()} | nil, separation: (Visualize.Layout.Hierarchy.t(), Visualize.Layout.Hierarchy.t() -> number()) | nil, size: {number(), number()} | nil }
Functions
@spec generate(t(), Visualize.Layout.Hierarchy.t()) :: Visualize.Layout.Hierarchy.t()
Generates the tree layout, positioning all nodes.
Without size or node_size the coordinates are raw: x in separation units with
the root at 0, y the depth.
@spec new() :: t()
Creates a new tree layout
Sets the fixed node size.
Unlike size/2, this sets a fixed spacing between nodes rather than scaling to fit a container.
@spec separation(t(), (Visualize.Layout.Hierarchy.t(), Visualize.Layout.Hierarchy.t() -> number())) :: t()
Sets the separation function between nodes.
The function receives two nodes and returns the desired separation. Default is 1 for siblings, 2 for non-siblings.
Sets the size of the layout.
The tree will be scaled to fit within [width, height].