Function edge_degree_ratio_sum 

pub fn edge_degree_ratio_sum(graph: &Graph) -> IgraphResult<f64>

Compute the edge degree ratio sum.

Σ_{(u,v)∈E} min(d(u),d(v)) / max(d(u),d(v))

Each edge contributes a value in (0, 1]. Equals m for regular graphs. Self-loops and edges with a degree-0 endpoint are skipped. Returns 0.0 for edgeless graphs.

Examples

use rust_igraph::{Graph, edge_degree_ratio_sum};

// K_3: 3 edges, all (2,2) → 3·1.0 = 3.0
let g = Graph::from_edges(&[(0,1),(1,2),(0,2)], false, Some(3)).unwrap();
assert!((edge_degree_ratio_sum(&g).unwrap() - 3.0).abs() < 1e-10);