找到两个2跳邻域图？

Question

我有感兴趣的节点，并且能够提取子图（下面的代码），但我相信 NetworkX

subgraph()

或

induced_subgraph()

只能提取节点的 1 跳邻域。

## Extract subgraph using nodes of interest (list)
G_S = induced_subgraph(G, S) # S is nodes of interest (list)

我查看了Ego Graph，但它只提取单个节点上的图。 如何提取 2 或 3 跳（甚至更多）子图？如果无法使用 NetworkX，graph-tool 是否有可以提取 k 跳子图的功能？

尝试 2 跳子图：

def extend_subgraph(G, S):
    # Start with the original set of nodes of interest
    extended_nodes = set(S)
    
    # Loop over each node in the current subgraph
    for node in S:
        # Get 1-hop neighbors of this node
        one_hop = set(nx.neighbors(G, node))
        
        # For each 1-hop neighbor, get its 1-hop neighbors
        for neighbor in one_hop:
            if neighbor not in extended_nodes:
                extended_nodes.add(neighbor)
                neighbors_of_neighbor = set(nx.neighbors(G, neighbor))
                
                # Add the 1-hop neighbors of the neighbor if they haven't been seen
                extended_nodes.update(neighbors_of_neighbor - extended_nodes)

    # Create a new subgraph with the extended set of nodes
    G_extended_subgraph = G.subgraph(extended_nodes)
    
    return G_extended_subgraph

G2 = extend_subgraph(G, S)

Answer 1

如果格式灵活，您可以使用 dgl 来表示您的图，并使用 khop_out_subgraph 函数提取所需的 k 跳子图。然后根据需要使用方法 to_networkx 转换回 networkx。