#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Example using the NetworkX ego_graph() function to return the main egonet of
the largest hub in a Barabási-Albert network.
"""
# Author: Drew Conway (drew.conway@nyu.edu)
from operator import itemgetter
import networkx as nx
import matplotlib.pyplot as plt
if __name__ == '__main__':
# Create a BA model graph
n=1000
m=2
G=nx.generators.barabasi_albert_graph(n,m)
# find node with largest degree
node_and_degree=G.degree()
(largest_hub,degree)=sorted(node_and_degree.items(),key=itemgetter(1))[-1]
# Create ego graph of main hub
hub_ego=nx.ego_graph(G,largest_hub)
# Draw graph
pos=nx.spring_layout(hub_ego)
nx.draw(hub_ego,pos,node_color='b',node_size=50,with_labels=False)
# Draw ego as large and red
nx.draw_networkx_nodes(hub_ego,pos,nodelist=[largest_hub],node_size=300,node_color='r')
plt.savefig('ego_graph.png')
plt.show()
