use weavatrix_graph::{
Direction, EdgeEndpoints, NodeIndex, Topology, betweenness_centrality, closeness_centrality,
cycle_basis, eigenvector_centrality, k_core_numbers, katz_centrality,
label_propagation_communities,
};
fn topology(node_count: usize, edges: &[(u32, u32)]) -> Topology {
Topology::try_from_edges(
node_count,
edges.iter().map(|&(source, target)| {
EdgeEndpoints::new(NodeIndex::new(source), NodeIndex::new(target))
}),
)
.unwrap()
}
fn score(scores: &[(NodeIndex, f64)], node: u32) -> f64 {
scores
.iter()
.find(|(candidate, _)| *candidate == NodeIndex::new(node))
.unwrap()
.1
}
#[test]
fn path_centralities_rank_the_bridge_node_highest() {
let graph = topology(3, &[(0, 1), (1, 0), (1, 2), (2, 1)]);
let betweenness = betweenness_centrality(&graph, Direction::Both, true);
let closeness = closeness_centrality(&graph, Direction::Both);
assert!(score(&betweenness, 1) > score(&betweenness, 0));
assert!(score(&closeness, 1) > score(&closeness, 0));
assert!((score(&betweenness, 0) - score(&betweenness, 2)).abs() < f64::EPSILON);
}
#[test]
fn spectral_centralities_converge_and_rank_a_star_center_first() {
let graph = topology(
5,
&[
(0, 1),
(1, 0),
(0, 2),
(2, 0),
(0, 3),
(3, 0),
(0, 4),
(4, 0),
],
);
let eigenvector = eigenvector_centrality(&graph, 1_000, 1e-10).unwrap();
let katz = katz_centrality(&graph, 0.1, 1.0, 1_000, 1e-10).unwrap();
assert!(eigenvector.converged());
assert!(katz.converged());
assert!(score(eigenvector.scores(), 0) > score(eigenvector.scores(), 1));
assert!(score(katz.scores(), 0) > score(katz.scores(), 1));
}
#[test]
fn core_cycle_and_community_analysis_are_deterministic() {
let graph = topology(6, &[(0, 1), (1, 2), (2, 0), (3, 4), (4, 5), (5, 3)]);
let cores = k_core_numbers(&graph);
assert!(cores.iter().all(|(_, core)| *core == 2));
assert_eq!(cycle_basis(&graph).len(), 2);
let communities = label_propagation_communities(&graph, 100);
assert!(communities.converged());
assert_eq!(communities.groups().len(), 2);
}