networkx.algorithms.swap.double_edge_swap

double_edge_swap(G, nswap=1, max_tries=100, seed=None)[source]

Swap two edges in the graph while keeping the node degrees fixed.

A double-edge swap removes two randomly chosen edges u-v and x-y and creates the new edges u-x and v-y:

u--v            u  v
       becomes  |  |
x--y            x  y

If either the edge u-x or v-y already exist no swap is performed and another attempt is made to find a suitable edge pair.

Parameters
Ggraph

An undirected graph

nswapinteger (optional, default=1)

Number of double-edge swaps to perform

max_triesinteger (optional)

Maximum number of attempts to swap edges

seedinteger, random_state, or None (default)

Indicator of random number generation state. See Randomness.

Returns
Ggraph

The graph after double edge swaps.

Notes

Does not enforce any connectivity constraints.

The graph G is modified in place.