Function inverse_degree_power 

pub fn inverse_degree_power(graph: &Graph, k: f64) -> IgraphResult<f64>

Compute the inverse degree power index.

ID_k(G) = Σ_v 1/d(v)^k for d(v) > 0.

For k = 1 this equals the inverse degree index. Vertices with degree 0 are skipped.

Examples

use rust_igraph::{Graph, inverse_degree_power};

// K_3: d=(2,2,2), k=2 → 3·(1/4) = 0.75
let g = Graph::from_edges(&[(0,1),(1,2),(0,2)], false, Some(3)).unwrap();
assert!((inverse_degree_power(&g, 2.0).unwrap() - 0.75).abs() < 1e-10);