Function hrg_sample 

pub fn hrg_sample(hrg: &HrgTree, seed: u64) -> IgraphResult<Graph>

Sample a random graph from a hierarchical random graph model.

For each pair of leaf vertices (i, j), an undirected edge is added with probability equal to the connection probability at their lowest common ancestor in the dendrogram.

seed initialises the internal PRNG. Same (hrg, seed) always produces the same graph.

Example

use rust_igraph::{HrgTree, hrg_sample};

let mut hrg = HrgTree::new(4);
hrg.left[0] = -2;  hrg.right[0] = -3;  hrg.prob[0] = 0.5;
hrg.left[1] = 0;   hrg.right[1] = 1;   hrg.prob[1] = 1.0;
hrg.left[2] = 2;   hrg.right[2] = 3;   hrg.prob[2] = 1.0;
hrg.vertices = vec![4, 2, 2];
hrg.edges = vec![6, 2, 2];

let g = hrg_sample(&hrg, 42).unwrap();
assert_eq!(g.vcount(), 4);
// With prob=1.0 within subtrees, leaves 0-1 and 2-3 are always connected