Function adjacency_spectral_embedding 

pub fn adjacency_spectral_embedding(
    graph: &Graph,
    no: usize,
    weights: Option<&[f64]>,
    which: SpectralWhich,
    scaled: bool,
    cvec: Option<&[f64]>,
) -> IgraphResult<AdjacencySpectralEmbeddingResult>

Compute the adjacency spectral embedding of an undirected graph.

Decomposes the (optionally augmented) adjacency matrix A + diag(cvec) into its top eigenpairs and returns the eigenvectors as vertex embeddings.

no: embedding dimension (number of eigenpairs to compute).

weights: optional edge weights. Must have length ecount if provided.

which: which eigenvalues to use. SpectralWhich::LargestAlgebraic is the default in igraph.

scaled: if true, multiply each eigenvector column by sqrt(|eigenvalue|), giving X = U D^(1/2).

cvec: optional diagonal augmentation vector. If Some(&[c]) (a single element), c is added to every diagonal entry. If Some(&[c0, c1, ..., cn-1]) (length = vcount), vertex i gets c_i added to its diagonal. Default is zero augmentation.

Edge directions are ignored (the graph is treated as undirected).

Examples

use rust_igraph::{Graph, adjacency_spectral_embedding, SpectralWhich};

let mut g = Graph::with_vertices(4);
g.add_edge(0, 1).unwrap();
g.add_edge(1, 2).unwrap();
g.add_edge(2, 3).unwrap();
g.add_edge(0, 3).unwrap();

let r = adjacency_spectral_embedding(&g, 2, None, SpectralWhich::LargestAlgebraic,
                                      false, None).unwrap();
assert_eq!(r.eigenvalues.len(), 2);
assert_eq!(r.embedding.len(), 4);
assert_eq!(r.embedding[0].len(), 2);