Function sample_dirichlet 

pub fn sample_dirichlet(
    n: usize,
    alpha: &[f64],
    seed: u64,
) -> IgraphResult<Vec<Vec<f64>>>

Sample points from a Dirichlet distribution.

Generates n vectors drawn from a Dirichlet distribution with concentration parameters alpha. Each sample sums to 1.0. Uses the Gamma-based method: draw independent Gamma(alpha_i, 1) values and normalize.

Returns a Vec<Vec<f64>> where each inner Vec has alpha.len() elements summing to 1.0.

Errors

Returns InvalidArgument if:

• alpha.len() < 2
• Any element of alpha is non-positive.

Examples

use rust_igraph::sample_dirichlet;

let alpha = [1.0, 2.0, 3.0];
let samples = sample_dirichlet(5, &alpha, 42).unwrap();
assert_eq!(samples.len(), 5);
for s in &samples {
    assert_eq!(s.len(), 3);
    let sum: f64 = s.iter().sum();
    assert!((sum - 1.0).abs() < 1e-10);
    for &v in s {
        assert!(v >= 0.0);
    }
}