navigable_small_world_graph

navigable_small_world_graph(n, p=1, q=1, r=2, dim=2, seed=None)

Returns a navigable small-world graph.

A navigable small-world graph is a directed grid with additional long-range connections that are chosen randomly.

[…] we begin with a set of nodes […] that are identified with the set of lattice points in an \(n \times n\) square, \(\{(i, j): i \in \{1, 2, \ldots, n\}, j \in \{1, 2, \ldots, n\}\}\), and we define the lattice distance between two nodes \((i, j)\) and \((k, l)\) to be the number of “lattice steps” separating them: \(d((i, j), (k, l)) = |k - i| + |l - j|\).

For a universal constant \(p >= 1\), the node \(u\) has a directed edge to every other node within lattice distance \(p\)—these are its local contacts. For universal constants \(q >= 0\) and \(r >= 0\) we also construct directed edges from \(u\) to \(q\) other nodes (the long-range contacts) using independent random trials; the \(i\) has endpoint \(v\) with probability proportional to \([d(u,v)]^{-r}\).

—[1]

Parameters

nint

The length of one side of the lattice; the number of nodes in the graph is therefore \(n^2\).

pint

The diameter of short range connections. Each node is joined with every other node within this lattice distance.

qint

The number of long-range connections for each node.

rfloat

Exponent for decaying probability of connections. The probability of connecting to a node at lattice distance \(d\) is \(1/d^r\).

dimint

Dimension of grid

seedinteger, random_state, or None (default)

Indicator of random number generation state. See Randomness.

References

1

J. Kleinberg. The small-world phenomenon: An algorithmic perspective. Proc. 32nd ACM Symposium on Theory of Computing, 2000.