"""Plot iso[49] at n=9, the counterexample to Conjecture 4.4.""" import sys import os sys.path.insert(0, '/Users/didericis/Code/math-research/papers/' 'level_resolutions_of_maximal_planar_graphs/experiments') import networkx as nx import matplotlib.pyplot as plt from triangulation_gen import enumerate_all_triangulations OUT_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__))) tris = enumerate_all_triangulations(9) G = tris[49] print(f'iso[49] degree sequence: {sorted([G.degree(v) for v in G.nodes()], reverse=True)}') print(f'iso[49] edges: {sorted(G.edges())}') # Use planar layout _, emb = nx.check_planarity(G) pos = nx.combinatorial_embedding_to_pos(emb) fig, ax = plt.subplots(figsize=(8, 7)) nx.draw_networkx_edges(G, pos, ax=ax, edge_color='#333', width=1.5) # Color vertices by degree degree_color = {4: '#3b82f6', 5: '#dc2626'} node_colors = [degree_color[G.degree(v)] for v in G.nodes()] nx.draw_networkx_nodes(G, pos, ax=ax, node_color=node_colors, node_size=600, edgecolors='black', linewidths=1.2) nx.draw_networkx_labels(G, pos, ax=ax, font_color='white', font_size=11, font_weight='bold') ax.set_aspect('equal'); ax.axis('off') ax.set_title('iso[49] at $n=9$: degree sequence (5,5,5,5,5,5,4,4,4).\n' 'NOT a valid derived level graph of any Even Level Graph.\n' 'Blue = degree 4, Red = degree 5.', fontsize=11) fig.tight_layout() out = os.path.join(OUT_DIR, 'fig_n9_counterexample.png') fig.savefig(out, dpi=180, bbox_inches='tight') plt.close(fig) print(f'wrote {out}')