# dgl.sampling.node2vec_random_walk¶

dgl.sampling.node2vec_random_walk(g, nodes, p, q, walk_length, prob=None, return_eids=False)[source]

Generate random walk traces from an array of starting nodes based on the node2vec model. Paper: node2vec: Scalable Feature Learning for Networks.

The returned traces all have length walk_length + 1, where the first node is the starting node itself.

Note that if a random walk stops in advance, DGL pads the trace with -1 to have the same length.

Parameters
• g (DGLGraph) –

The graph. Must be on CPU.

Note that node2vec only support homogeneous graph.

• nodes (Tensor) –

Node ID tensor from which the random walk traces starts.

The tensor must be on CPU, and must have the same dtype as the ID type of the graph.

• p (float) – Likelihood of immediately revisiting a node in the walk.

• q (float) – Control parameter to interpolate between breadth-first strategy and depth-first strategy.

• walk_length (int) – Length of random walks.

• prob (str, optional) –

The name of the edge feature tensor on the graph storing the (unnormalized) probabilities associated with each edge for choosing the next node.

The feature tensor must be non-negative and the sum of the probabilities must be positive for the outbound edges of all nodes (although they don’t have to sum up to one). The result will be undefined otherwise.

If omitted, DGL assumes that the neighbors are picked uniformly.

• return_eids (bool, optional) –

If True, additionally return the edge IDs traversed.

Default: False.

Returns

• traces (Tensor) – A 2-dimensional node ID tensor with shape (num_seeds, walk_length + 1).

• eids (Tensor, optional) – A 2-dimensional edge ID tensor with shape (num_seeds, length). Only returned if return_eids is True.

Examples

>>> g1 = dgl.graph(([0, 1, 1, 2, 3], [1, 2, 3, 0, 0]))
>>> dgl.sampling.node2vec_random_walk(g1, [0, 1, 2, 0], 1, 1, walk_length=4)
tensor([[0, 1, 3, 0, 1],
[1, 2, 0, 1, 3],
[2, 0, 1, 3, 0],
[0, 1, 2, 0, 1]])

>>> dgl.sampling.node2vec_random_walk(g1, [0, 1, 2, 0], 1, 1, walk_length=4, return_eids=True)
(tensor([[0, 1, 3, 0, 1],
[1, 2, 0, 1, 2],
[2, 0, 1, 2, 0],
[0, 1, 2, 0, 1]]),
tensor([[0, 2, 4, 0],
[1, 3, 0, 1],
[3, 0, 1, 3],
[0, 1, 3, 0]]))