python实现小世界网络生成

import matplotlib.pyplot as plt
import random as rd
import numpy as np
plt.rcParams['font.sans-serif'] = ['SimHei'] # 中文字体设置
plt.rcParams['axes.unicode_minus']=False
#小世界项目
def dian(N,K,P):
  global ls
  tim=[]
  for i in range(N):
    for j in range(1,K+1):
      ls[i]=ls.get(i,set())
      ls[i].add((i+j)%N)
      ls[i].add((i-j)%N)
      ls[(i-j)%N]=ls.get((i-j)%N,set())
      ls[(i-j)%N].add(i)
      ls[(i+j)%N]=ls.get((i+j)%N,set())
      ls[(i+j)%N].add(i)
  for i in range(N):
    for j in list(ls[i]):
      if rd.random()<=P:
        aa=ls[i].pop()
        a=set(range(N))
        a.discard(i)
        a=a^ls[i]
        for i in range(rd.randint(1,len(a)-1)):
          aa=a.pop()
        ls[aa].discard(i)
        b=a.pop()
        ls[i].add(b)
        ls[b].add(i)
  for i in range(N):
    tim.append(len(ls[i])*40-N)
  new=[]
  for i in range(len(ls)):
    l=[]
    l.append(i)
    l+=list(ls[i])
    new.append(l)
  return new,tim
def hua(L,S):
  x=np.linspace(0,100,len(L))
  y=np.sqrt(np.abs(10000-(x-50)**2))
  plt.scatter(x,y,s=S,edgecolor='k',alpha=0.7)
  for i in range(len(L)):
    plt.text(x[i]-0.13,y[i]-0.015,str(S[i]//40+1))
    for j in L[i]:
      plt.plot(list((x[i],x[j])),list((y[i],y[j]))\
           ,color='gray',linewidth=1,alpha=0.7)
  plt.title('小世界网络初步')
  plt.xticks([])
  plt.yticks([])
  plt.axis('off')
  plt.savefig('niu.png')
ls={}
l,k=dian(20,3,0.5) #不要超过40哦~
hua(l,k)