netket.graph.Graph

class netket.graph.Graph

Bases: AbstractGraph

A simple implementation of Graph based on an external graph library.

The underlying implementation is based on igraph and supports conversion to networkx, but this is an implementation detail and could be changed in the future.

Inheritance

__init__(edges, n_nodes=None)

Construct the a graph starting from a list of edges and optionally a given number of nodes.

Parameters:

• edges (Union[Sequence[tuple[int, int]], Sequence[tuple[int, int, int]]]) – list of (undirected) edges

• n_nodes (Optional[int]) – number of nodes. Can be used to specify the number vertices in the graph if not all vertices appear in an edge.

Attributes

edge_colors

Sequence of edge colors, in the order of the edges returned by self.edges.

n_edges

The number of edges in the graph.

n_nodes

The number of nodes (or vertices) in the graph

Methods

adjacency_list()

List containing the adjacency list of the graph where each node is represented by an integer in [0, n_nodes)

Return type:

list[list]

automorphisms()

Symmetry group containing the automorphisms of the graph

Return type:

PermutationGroup

distances()

List containing the distances between the nodes. The distance between unconnected nodes (no path exists between them) is set to -1

Return type:

list[list]

edges(color=None, *, return_color=False, filter_color=None)

Returns the sequence of edges of the graph.

Parameters:

• return_color (bool) – If True, return edges with added color information.

• filter_color (Optional[int]) – If set, return only edges of the given color.

Return type:

Union[Sequence[tuple[int, int]], Sequence[tuple[int, int, int]]]

Returns:

A sequence of edges as tuples (i, j) or, if return_color is passed, a sequence of tuples (i, j, c) with c indicating the color of the respective edge.

classmethod from_igraph(graph)

Creates a new Graph instance from an igraph.Graph instance.

Return type:

Graph

Parameters:

graph (Graph)

classmethod from_networkx(graph)

Creates a new Graph instance from a networkx graph.

Return type:

Graph

is_bipartite()

True if the graph is bipartite

Return type:

bool

is_connected()

True if the graph is connected

Return type:

bool

nodes()

Iterator over the nodes of the graph

Return type:

Sequence[int]

to_igraph()

Returns a copy of this graph as an igraph.Graph instance.

to_networkx()

Returns a copy of this graph as an igraph.Graph instance. This method requires networkx to be installed.