retworkx.vf2_mapping¶
- vf2_mapping(first, second, node_matcher=None, edge_matcher=None, id_order=True, subgraph=False, induced=True, call_limit=None)[source]¶
- vf2_mapping(first: retworkx.PyDiGraph, second, node_matcher=None, edge_matcher=None, id_order=True, subgraph=False, induced=True, call_limit=None)
- vf2_mapping(first: retworkx.PyGraph, second, node_matcher=None, edge_matcher=None, id_order=True, subgraph=False, induced=True, call_limit=None)
Return an iterator over all vf2 mappings between two graphs.
This funcion will run the vf2 algorithm used from
is_isomorphic()
andis_subgraph_isomorphic()
but instead of returning a boolean it will return an iterator over all possible mapping of node ids found fromfirst
tosecond
. If the graphs are not isomorphic then the iterator will be empty. A simple example that retrieves one mapping would be:graph_a = retworkx.generators.path_graph(3) graph_b = retworkx.generators.path_graph(2) vf2 = retworkx.vf2_mapping(graph_a, graph_b, subgraph=True) try: mapping = next(vf2) except StopIteration: pass
- Parameters
first – The first graph to find the mapping for
second – The second graph to find the mapping for
node_matcher – An optional python callable object that takes 2 positional arguments, one for each node data object in either graph. If the return of this function evaluates to True then the nodes passed to it are viewed as matching.
edge_matcher – A python callable object that takes 2 positional one for each edge data object. If the return of this function evaluates to True then the edges passed to it are viewed as matching.
id_order (bool) – If set to
False
this function will use a heuristic matching order based on [VF2] paper. Otherwise it will default to matching the nodes in order specified by their ids.subgraph (bool) – If set to
True
the function will return the subgraph isomorphic found between the graphs.induced (bool) – If set to
True
this function will check the existence of a node-induced subgraph of first isomorphic to second graph. Default:True
.call_limit (int) – An optional bound on the number of states that VF2 algorithm visits while searching for a solution. If it exceeds this limit, the algorithm will stop. Default:
None
.
- Returns
An iterator over dicitonaries of node indices from
first
to node indices insecond
representing the mapping found.- Return type
Iterable[NodeMap]