Rendering a Dot Representation of a Graph in Quarto Using Petgraph and Petgraph-evcxr

In this post I want to quickly showcase the use of the Petgraph and Petgraph-evcxr packages. Petgraph is a popular graph data structures and algorithms crate available for Rust. Petgraph-evcxr is a tool that makes it possible to easily visualize graphs created using Petgraph within Jupyter notebooks. This in turn allows us to visualize such graphs within Quarto.

Thus we need to include them as dependencies.

extern crate petgraph;
use petgraph::graph::Graph;
use petgraph_evcxr::draw_graph;

fn main() {
    let mut g: Graph<&str, &str> = Graph::new();
    let rock = g.add_node("Rock");
    let paper = g.add_node("Paper");
    let scissors = g.add_node("Scissors");

    g.add_edge(rock, scissors, "beats");
    g.add_edge(paper, rock, "beats");
    g.add_edge(scissors, paper, "beats");

    draw_graph(&g);
}

The output would be a graph visualization in the Jupyter/evcxr context. For this static post conversion, the code is shown; evcxr-specific rendering is not available in this environment.

Mermaid is an easy alternative

One should be aware of the fact that it is easy to produce similar diagrams with Mermaid.

flowchart TD

Rock -->|Beats| Scissors
Paper -->|Beats| Rock
Scissors -->|Beats| Paper

flowchart TD

Rock -->|Beats| Scissors
Paper -->|Beats| Rock
Scissors -->|Beats| Paper

Perhaps a small advantage of using Petgraph here is that you can programmatically generate the properties of the diagram, as other tools such as networkx would let us do. Above I just wanted to show that we ‘can’ produce such diagrams starting with Rust.