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Note

This documents the development version of NetworkX. Documentation for the current release can be found here.

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networkx.linalg.laplacianmatrix.normalized_laplacian_matrix¶

normalized_laplacian_matrix(G, nodelist=None, weight='weight')[source]¶

Returns the normalized Laplacian matrix of G.

The normalized graph Laplacian is the matrix

\[N = D^{-1/2} L D^{-1/2}\]

where L is the graph Laplacian and D is the diagonal matrix of node degrees.

Parameters

G (graph) – A NetworkX graph
nodelist (list, optional) – The rows and columns are ordered according to the nodes in nodelist. If nodelist is None, then the ordering is produced by G.nodes().
weight (string or None, optional (default=’weight’)) – The edge data key used to compute each value in the matrix. If None, then each edge has weight 1.

Returns

N – The normalized Laplacian matrix of G.

Return type

Scipy sparse matrix

Notes

For MultiGraph/MultiDiGraph, the edges weights are summed. See to_numpy_array for other options.

If the Graph contains selfloops, D is defined as diag(sum(A,1)), where A is the adjacency matrix 2.