contracted_nodes(G, u, v, self_loops=True, copy=True)
Node contraction identifies the two nodes as a single node incident to any edge that was incident to the original two nodes.
For multigraphs, the edge keys for the realigned edges may not be the same as the edge keys for the old edges. This is natural because edge keys are unique only within each pair of nodes.
For non-multigraphs where u and v are adjacent to a third node :None:None:`w`, the edge (v, :None:None:`w`) will be contracted into the edge (u, :None:None:`w`) with its attributes stored into a "contraction" attribute.
This function is also available as :None:None:`identified_nodes`.
The graph whose nodes will be contracted.
Must be nodes in G.
If this is True, any edges joining u and v in G become self-loops on the new node in the returned graph.
If this is True (default True), make a copy of G and return that instead of directly changing G.
If Copy is True, A new graph object of the same type as G (leaving G unmodified) with u and v identified in a single node. The right node v will be merged into the node u, so only u will appear in the returned graph. If copy is False, Modifies G with u and v identified in a single node. The right node v will be merged into the node u, so only u will appear in the returned graph.
Returns the graph that results from contracting u and v.
Contracting two nonadjacent nodes of the cycle graph on four nodes :None:None:`C_4` yields the path graph (ignoring parallel edges):
>>> G = nx.cycle_graph(4)
... M = nx.contracted_nodes(G, 1, 3)
... P3 = nx.path_graph(3)
... nx.is_isomorphic(M, P3) True
>>> G = nx.MultiGraph(P3)
... M = nx.contracted_nodes(G, 0, 2)
... M.edges MultiEdgeView([(0, 1, 0), (0, 1, 1)])
>>> G = nx.Graph([(1, 2), (2, 2)])
... H = nx.contracted_nodes(G, 1, 2, self_loops=False)
... list(H.nodes()) [1]
>>> list(H.edges()) [(1, 1)]See :
The following pages refer to to this document either explicitly or contain code examples using this.
networkx.algorithms.minors.contraction.contracted_nodes
networkx.algorithms.minors.contraction.contracted_edge
Hover to see nodes names; edges to Self not shown, Caped at 50 nodes.
Using a canvas is more power efficient and can get hundred of nodes ; but does not allow hyperlinks; , arrows or text (beyond on hover)
SVG is more flexible but power hungry; and does not scale well to 50 + nodes.
All aboves nodes referred to, (or are referred from) current nodes; Edges from Self to other have been omitted (or all nodes would be connected to the central node "self" which is not useful). Nodes are colored by the library they belong to, and scaled with the number of references pointing them