pub fn modularity_weighted_directed(
graph: &Graph,
membership: &[u32],
resolution: f64,
weights: &[f64],
) -> IgraphResult<Option<f64>>Expand description
Directed weighted modularity (Leicht-Newman, ALGO-CO-006c follow-up).
Combines the directed normalisation of modularity_directed
(split out-strength / in-strength) with the per-edge weighting of
modularity_weighted:
Q = (1 / W) Σ_{ij} (W_ij − γ s_out_i * s_in_j / W) δ(c_i, c_j)where W = Σ_e w_e, s_out_i = Σ_{j: i→j} w_{ij}, s_in_j = Σ_{i: i→j} w_{ij},
and W_ij is the weighted adjacency. Undirected graphs route to
modularity_weighted (matching python-igraph’s “directed flag
ignored on undirected” semantics).