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barbell_graph

barbell_graph(m1, m2, create_using=None)

Return the Barbell Graph: two complete graphs connected by a path.

For m1 > 1 and m2 >= 0.

Two identical complete graphs K_{m1} form the left and right bells, and are connected by a path P_{m2}.

The 2*m1+m2 nodes are numbered

0,…,m1-1 for the left barbell, m1,…,m1+m2-1 for the path, and m1+m2,…,2*m1+m2-1 for the right barbell.

The 3 subgraphs are joined via the edges (m1-1,m1) and (m1+m2-1,m1+m2). If m2=0, this is merely two complete graphs joined together.

This graph is an extremal example in David Aldous and Jim Fill’s etext on Random Walks on Graphs.