Python 网络 x : edge contraction

Question

我有一个 NetworkX图形。我想知道怎么做edge contraction多个节点之间。

例如，如果我想收缩 X、Y 和 Z:

         _ node A _
       _/    |     \_
node X --- node Y --- node Z

会变成

           node A 
             |     
           node XYZ (or whatever X/Y/Z)

图形创建不是问题。有用。我想通过合并具有相同“含义”的节点来减少图形:我称之为“end lvl”(节点名称长度等于 7)并且链接在一起的节点。

我在NetworkX中找到了压缩功能，所以我尝试使用它:

# edge contraction for same nodes
# for each node, get the links to other nodes "end lvl"
# if there is such a link, it means that these node are
# the sames
#
# copy graph
I = G
for n,d in G.nodes(data=True):
    if n in I.nodes():
        if len(n) == 7:
            # list of nodes adjacent to n : filter only "end lvl" nodes
            neighbors = [ node for node in I.neighbors(n) if len(node) == 7 ]
            nodes_to_merges = neighbors.append(n)
            I = nx.condensation(I,scc=nodes_to_merges)

当我转换为 JSON 时得到的是:

{"directed": true, "graph": [], "nodes": [{"id": 0}], "links": [], "multigraph": false}

如您所见，存在问题...

对函数的引用是here .

Answer 1

怎么样:

add_node(XYZ)
add_edge(XYZ, A)
for edge incident on (X, Y, Z):
    v = nodes in edge not in (X, Y, Z, A)
    if v:
       remove_edge(edge)
       add_edge(v, XYZ)
for node in (X, Y, Z):
    remove_node(node)