modgeosys-graph-algorithms 0.1.0

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modgeosys-graph-algorithms: Graph Algorithms

A repository for [hopefully] clean, readable, and easily-called implementations of some navigation, path planning, and obstacle avoidance algorithms I will be using in the near future, written in modern Python and/or Rust with Python bindings. I'll be adding more algorithm implementations over time.

Algorithms: Currently implemented + planned

• A* - Graph path search algorithm.
  • code-complete in both Python and Rust.
  • Needs a more thorough test suite.
• Prim's algorithm - Prim's Minimum Spanning Tree algorithm.
  • Planned.

Usage

A* (Python)

from modgeosys.graph.a_star import a_star
from modgeosys.graph.types import Node, Edge, Graph
from modgeosys.graph.distance import manhattan_distance, euclidean_distance

# Define a graph.
nodes = [Node(coordinates=(0.0, 0.0)),
         Node(coordinates=(0.0, 2.0)),
         Node(coordinates=(1.0, 0.0)),
         Node(coordinates=(2.0, 1.0)),
         Node(coordinates=(2.0, 3.0))]
edges = (Edge(weight=2.0, node_indices=frozenset((0, 1))),
         Edge(weight=1.0, node_indices=frozenset((0, 2))),
         Edge(weight=1.0, node_indices=frozenset((2, 3))),
         Edge(weight=3.0, node_indices=frozenset((1, 4))),
         Edge(weight=1.0, node_indices=frozenset((3, 4))))
graph = Graph(nodes=nodes, edges=edges)

# Call the A* function.
path = a_star(graph=graph, start_node_index=0, goal_node_index=4, heuristic_distance=manhattan_distance)

# Report the resulting path.
print(path)

A* (Rust)

use std::collections::HashSet;

use modgeosys_graph::a_star::a_star;
use modgeosys_graph::types::{Node, Edge, Graph};
use modgeosys_graph::distance::manhattan_distance;

fn main()
{
  // Define a graph.
  let nodes = vec![Node::new(vec![0.0, 0.0]),
                   Node::new(vec![0.0, 2.0]),
                   Node::new(vec![1.0, 0.0]),
                   Node::new(vec![2.0, 1.0]),
                   Node::new(vec![2.0, 3.0])];
  let edges = vec![Edge::new(2.0, HashSet::from([0, 1])),
                   Edge::new(1.0, HashSet::from([0, 2])),
                   Edge::new(1.0, HashSet::from([2, 3])),
                   Edge::new(3.0, HashSet::from([1, 4])),
                   Edge::new(1.0, HashSet::from([3, 4]))];
  let graph = Graph::new(nodes, edges);

  // Call the A* function.
  let path = a_star(&graph, 0, 4, manhattan_distance).unwrap();

  // Report the resulting path.
  println!("{:?}", path);
}