yog - v4.0.0

yog/io/dot

DOT (Graphviz) format export for visualizing graphs.

This module exports graphs to the DOT language, which is the native format for Graphviz - a powerful open-source graph visualization tool. The exported files can be rendered to PNG, SVG, PDF, and other formats using the dot, neato, circo, or other Graphviz layout engines.

Quick Start

import yog/io/dot

// Export with default styling
let dot_string = dot.to_string(my_graph)

// Write to file and render with Graphviz CLI
// $ dot -Tpng output.dot -o graph.png

Customization

Use DotOptions to customize:

Rendering Options

EngineBest For
dotHierarchical layouts (DAGs, trees)
neatoSpring-based layouts (undirected)
circoCircular layouts
fdpForce-directed layouts
sfdpLarge graphs

References

Types

DotOptions

</>

Options for customizing DOT (Graphviz) diagram rendering.

pub type DotOptions {
  DotOptions(
    node_label: fn(Int, String) -> String,
    edge_label: fn(String) -> String,
    highlighted_nodes: option.Option(List(Int)),
    highlighted_edges: option.Option(List(#(Int, Int))),
    node_shape: String,
    highlight_color: String,
  )
}

Constructors 

  • DotOptions(
  node_label: fn(Int, String) -> String,
  edge_label: fn(String) -> String,
  highlighted_nodes: option.Option(List(Int)),
  highlighted_edges: option.Option(List(#(Int, Int))),
  node_shape: String,
  highlight_color: String,
)

    Arguments

    node_label

    Function to convert node ID and data to a display label

    edge_label

    Function to convert edge weight to a display label

    highlighted_nodes

    Optional list of node IDs to highlight

    highlighted_edges

    Optional list of edges to highlight as (from, to) pairs

    node_shape

    Node shape (e.g., “circle”, “box”, “ellipse”)

    highlight_color

    Highlight color for nodes/edges

Values

default_dot_options

</> 
pub fn default_dot_options() -> DotOptions

Creates default DOT options with simple labeling.

path_to_dot_options

</> 
pub fn path_to_dot_options(
  path: utils.Path(e),
  base_options: DotOptions,
) -> DotOptions

Converts a shortest path result to highlighted DOT options.

Example

let path = pathfinding.shortest_path(
  in: graph,
  from: 1,
  to: 5,
  with_zero: "0",
  with_add: string_add, // Assume these exist or map to int/float
  with_compare: string_compare,
)

case path {
  Some(p) -> {
    let options = dot.path_to_dot_options(p, default_dot_options())
    let diagram = dot.to_dot(graph, options)
    io.println(diagram)
  }
  None -> io.println("No path found")
}

to_dot

</> 
pub fn to_dot(
  graph: model.Graph(String, String),
  options: DotOptions,
) -> String

Converts a graph to DOT (Graphviz) syntax.

The graph’s node data and edge data must be convertible to strings. Use the options to customize labels and highlighting.

Time Complexity: O(V + E)

Example

let graph =
  model.new(Directed)
  |> model.add_node(1, "Start")
  |> model.add_node(2, "Process")
  |> model.add_edge(from: 1, to: 2, with: "5")

let diagram = dot.to_dot(graph, default_dot_options())
// io.println(diagram)

This output can be processed by Graphviz tools (e.g., dot -Tpng -o graph.png):

digraph G {
  node [shape=ellipse];
  1 [label="Start"];
  2 [label="Process"];
  1 -> 2 [label="5"];
}
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