NetworkX nx.add_edges_from() 如何添加单向边？答案

【问题标题】：NetwrokX nx.add_edges_from() how to add a one way edge?NetworkX nx.add_edges_from() 如何添加单向边？
【发布时间】：2021-08-02 20:03:05
【问题描述】：

我正在尝试构建分销网络图。在过去，我使用 add_edges_from() 能够在 1 步中导入所有图形。我有几个单向边缘，但是当我导入其中一些时，它们正在反向导入。有没有办法指导 jupyter 使边缘成为单向边缘。具体来说： RIC -> MAR, VB->RIC, VB->WDC, AND RIC-> NCA & NCA-> VB 应该是不同容量的2路。

import networkx as nx
D = nx.Graph()
edges= [('CD', 'MAR', {'capacity': 200}), 
        ('CD', 'RIC', {'capacity': 200}), 
        ('CD', 'NCA',{'capacity': 150}), 
        ('RIC', 'NCA', {'capacity': 145}), 
        ('NCA', 'RIC', {'capacity': 125}), 
        ('RIC', 'MAR', {'capacity': 100}), 
        ('RIC', 'WDC', {'capacity': 230}), 
        ('NCA', 'WDC', {'capacity': 100}), 
        ('VB', 'RIC', {'capacity': 275}), 
        ('MAR', 'WDC', {'capacity': 150}), 
        ('NCA', 'VB', {'capacity': 200}), 
        ('VB', 'NCA', {'capacity': 175}), 
        ('VB', 'WDC', {'capacity': 50})]
D.add_edges_from(edges)
print('Number of Nodes:',D.number_of_nodes())
print('Nodes:', list (D.nodes))
print( 'Number of Edges',D.number_of_edges())
for i in range(len(D.edges)):
    print('Edge:',list(D.edges)[i] ,list(D.edges.values())[i])
maxflow=nx.maximum_flow(D,'CD','WDC')
print('Flow from each node (From Node: {Node reciveing: Flow})')
for key in maxflow[1]:
    print(key, ' : ', maxflow[1][key])

感谢您的帮助！

【问题讨论】：

标签： networking graph jupyter-notebook networkx

【解决方案1】：

使用nx.DiGraph，有向图而不是nx.Graph，无向图。

import networkx as nx
D = nx.DiGraph()
edges= [('CD', 'MAR', {'capacity': 200}), 
        ('CD', 'RIC', {'capacity': 200}), 
        ('CD', 'NCA',{'capacity': 150}), 
        ('RIC', 'NCA', {'capacity': 145}), 
        ('NCA', 'RIC', {'capacity': 125}), 
        ('RIC', 'MAR', {'capacity': 100}), 
        ('RIC', 'WDC', {'capacity': 230}), 
        ('NCA', 'WDC', {'capacity': 100}), 
        ('VB', 'RIC', {'capacity': 275}), 
        ('MAR', 'WDC', {'capacity': 150}), 
        ('NCA', 'VB', {'capacity': 200}), 
        ('VB', 'NCA', {'capacity': 175}), 
        ('VB', 'WDC', {'capacity': 50})]
D.add_edges_from(edges)
nx.draw_networkx(D)

输出：

【讨论】：