fn get_node_betweenness_starting_from_sources()

in src/dachshund/algorithms/betweenness.rs [17:47]

• 30 lines of code
• 9 McCabe index (conditional complexity)

    fn get_node_betweenness_starting_from_sources(
        &self,
        sources: &[NodeId],
        check_is_connected: bool,
        nodes_in_connected_component: Option<Vec<NodeId>>,
    ) -> Result<HashMap<NodeId, f64>, &'static str> {
        if self.count_nodes() == 0 {
            return Err("Graph is empty");
        }
        if check_is_connected && !self.get_is_connected().unwrap() {
            return Err("Graph should be connected to compute betweenness.");
        }
        let mut path_counts: HashMap<NodeId, f64> = HashMap::new();
        for node_id in self.get_ids_iter() {
            path_counts.insert(*node_id, 0.0);
        }

        for source in sources.iter() {
            let (dist, parents) = self.get_shortest_paths(*source, &nodes_in_connected_component);
            let shortest_paths = self.enumerate_shortest_paths(&dist, &parents, *source);
            for paths in shortest_paths.values() {
                let weight: f64 = 0.5 / paths.len() as f64;
                for path in paths {
                    for id in path.iter().skip(1).rev().skip(1) {
                        *path_counts.get_mut(id).unwrap() += weight;
                    }
                }
            }
        }
        Ok(path_counts)
    }