Return the disjoint union of all graphs.
This operation forces distinct integer node labels starting with 0 for the first graph in the list and numbering consecutively.
| Parameters : | graphs : list
|
|---|---|
| Returns : | U : A graph with the same type as the first graph in list |
Notes
It is recommended that the graphs be either all directed or all undirected.
Graph, edge, and node attributes are propagated to the union graph. If a graph attribute is present in multiple graphs, then the value from the last graph in the list with that attribute is used.