Subgraph Networkx

Dear Group,

I have two questions, if I take a subseries of the matrix as in eigenvalue here, provided I have one graph of the full form in G, how may I show it, as if I do the nx.draw(G) it takes only the original graph.

import numpy import networkx as nx import matplotlib.pyplot as plt G=nx.Graph() G.add_edges_from([(1,2),(1,3),(1,3),(1,4),(1,5),(1,6),(1,7),(1,8)]) L =nx.laplacian(G) print L [[ 7. -1. -1. -1. -1. -1. -1. -1.] [-1. 1. 0. 0. 0. 0. 0. 0.] [-1. 0. 1. 0. 0. 0. 0. 0.] [-1. 0. 0. 1. 0. 0. 0. 0.] [-1. 0. 0. 0. 1. 0. 0. 0.] [-1. 0. 0. 0. 0. 1. 0. 0.] [-1. 0. 0. 0. 0. 0. 1. 0.] [-1. 0. 0. 0. 0. 0. 0. 1.]] print numpy.linalg.eigvals(L) [ 8.00000000e+00 2.22044605e-16 1.00000000e+00 1.00000000e+00 1.00000000e+00 1.00000000e+00 1.00000000e+00 1.00000000e+00]

for more than 1000 nodes it is coming too slow on Windows 7 machine with 3GB RAM.

If any one of the learned members can help.

Apology for any indentation error etc.

Thanking all in Advance,

Regards, Subhabrata Banerjee.