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comparison ch4ex4.py @ 23:74c9d126bd05

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Working on the SmallWorldGraph exercises.
author Brian Neal <bgneal@gmail.com>
date Wed, 02 Jan 2013 16:50:55 -0600
parents
children 5c2c4ce095ef
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22:84e183b40c63 23:74c9d126bd05
1 """This program performs item 4 in 4.4 exercise 4.
2
3 "Make a graph that replicates the line marked C(p)/C(0) in Figure 2 of the
4 paper. In other words, confirm that the clustering coefficient drops off slowly
5 for small values of p."
6
7 """
8 import random
9 import matplotlib.pyplot as pyplot
10
11 from Graph import Vertex
12 from SmallWorldGraph import SmallWorldGraph
13
14
15 title = 'C(p)/C(0)'
16
17 # compute C(0)
18 n = 1000
19 k = 10
20 vs = [Vertex(str(i)) for i in range(n)]
21 g = SmallWorldGraph(vs, k, 0.0)
22 c0 = g.clustering_coefficient()
23 print 'c0 =', c0
24
25 # compute data
26 p_vals = [0,
27 0.0001, 0.0002, 0.0004, 0.0006, 0.0008,
28 0.001, 0.002, 0.004, 0.006, 0.008,
29 0.01, 0.02, 0.04, 0.06, 0.08,
30 0.1, 0.2, 0.4, 0.6, 0.8,
31 1.0]
32
33 c_vals = []
34 for p in p_vals:
35 g = SmallWorldGraph(vs, k, p)
36 c_vals.append(g.clustering_coefficient() / c0)
37
38 # plot graph
39 pyplot.clf()
40 pyplot.xscale('log')
41 pyplot.yscale('log')
42 pyplot.title('')
43 pyplot.xlabel('p')
44 pyplot.ylabel('C(p)/C(0)')
45 pyplot.plot(p_vals, c_vals, label=title, color='green', linewidth=3)
46 pyplot.legend(loc=4)
47 pyplot.show()