Function reciprocity_ratio 

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

Compute the reciprocity ratio of the graph.

For directed graphs, the fraction of directed edges (u,v) for which the reverse edge (v,u) also exists. For undirected graphs, returns 1.0 (every edge is trivially reciprocal). Returns 0.0 for graphs with no edges.

Examples

use rust_igraph::{Graph, reciprocity_ratio};

// Undirected triangle → all reciprocal → 1.0
let g = Graph::from_edges(&[(0,1),(1,2),(0,2)], false, Some(3)).unwrap();
assert!((reciprocity_ratio(&g).unwrap() - 1.0).abs() < 1e-10);