import networkx as nx import numpy as np import matplotlib.pyplot as plt from scipy.linalg import eigh, sqrtm, inv Graph = nx.connected_watts_strogatz_graph(40,6,0.1) L = nx.laplacian_matrix(Graph).toarray() A = nx.adjacency_matrix(Graph).toarray() #D is the diagonal matrix of node degrees. D = L + A L_norm = nx.normalized_laplacian_matrix(Graph).toarray() val, vec = eigh(L_norm) fiedler = np.matmul(inv(sqrtm(D)),vec[:,1]) color_map = [] for vertex in fiedler: if vertex < 0: color_map.append("red") else: color_map.append("white") options = { "font_size": 15, "node_size": 550, "node_color": color_map, "linewidths": 1, "edgecolors": "black", "width": 2, "with_labels": True } pos = nx.spring_layout(Graph) plt.figure(figsize=(10,10)) nx.draw(Graph, pos, **options) plt.show()