python实现小世界网络生成

import matplotlib.pyplot as pltimport random as rdimport numpy as npplt.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,timdef 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)