Networkx的「generalized_laplacian（）」不再工作了嗎？

Question

這個例子（從Networkx手冊http://networkx.github.io/documentation/latest/examples/advanced/eigenvalues.html）：

#!/usr/bin/env python 
""" 
Create an G{n,m} random graph and compute the eigenvalues. 

Requires numpy or LinearAlgebra package from Numeric Python. 

Uses optional pylab plotting to produce histogram of eigenvalues. 

""" 
__author__ = """Aric Hagberg (hagberg@lanl.gov)""" 
__credits__ = """""" 
# Copyright (C) 2004-2006 by 
# Aric Hagberg <hagberg@lanl.gov> 
# Dan Schult <dschult@colgate.edu> 
# Pieter Swart <swart@lanl.gov> 
# All rights reserved. 
# BSD license. 

from networkx import * 
try: 
    import numpy.linalg 
    eigenvalues=numpy.linalg.eigvals 
except ImportError: 
    raise ImportError("numpy can not be imported.") 

try: 
    from pylab import * 
except: 
    pass 

n=1000 # 1000 nodes 
m=5000 # 5000 edges 

G=gnm_random_graph(n,m) 

L=generalized_laplacian(G) 
e=eigenvalues(L) 
print("Largest eigenvalue:", max(e)) 
print("Smallest eigenvalue:", min(e)) 
# plot with matplotlib if we have it 
# shows "semicircle" distribution of eigenvalues 
try: 
    hist(e,bins=100) # histogram with 100 bins 
    xlim(0,2) # eigenvalues between 0 and 2 
    show() 
except: 
    pass 

引發與networkx的最新版本以下錯誤：

Traceback (most recent call last): 
    File "Untitled 2.py", line 36, in <module> 
    L=generalized_laplacian(G) 
NameError: name 'generalized_laplacian' is not defined 

我應該怎麼去讓它工作？

Answer 1

這個例子肯定與newe斷了r版本的NetworkX。 這是一個工程：

import networkx as nx 
import numpy.linalg 
import matplotlib.pyplot as plt 

n = 1000 # 1000 nodes 
m = 5000 # 5000 edges 
G = nx.gnm_random_graph(n,m) 

L = nx.normalized_laplacian_matrix(G) 
e = numpy.linalg.eigvals(L.A) 
print("Largest eigenvalue:", max(e)) 
print("Smallest eigenvalue:", min(e)) 
plt.hist(e,bins=100) # histogram with 100 bins 
plt.xlim(0,2) # eigenvalues between 0 and 2 
plt.show() 

Answer 2

我覺得在this commit移除該名稱：

Deprecate non-"matrix" names in laplacian. 

Use laplacian_matrix, directed_laplacian_matrix, and normalized_laplacian_matrix only and deprecate other name aliases. 

從networkx/linalg/laplacianmatrix.py更改的行包括

-combinatorial_laplacian=laplacian_matrix 
-generalized_laplacian=normalized_laplacian_matrix 
-normalized_laplacian=normalized_laplacian_matrix 
-laplacian=laplacian_matrix 

所以我認爲你可以使用normalized_laplacian_matrix代替：

>>> normalized_laplacian_matrix(G) 
<1000x1000 sparse matrix of type '<type 'numpy.float64'>' 
    with 11000 stored elements in Compressed Sparse Row format>