xgi.stats.dinodestats

Node statistics.

This module is part of the stats package, and it defines node-level statistics. That is, each function defined in this module is assumed to define a node-quantity mapping. Each callable defined here is accessible via a Network object, or a NodeView object. For more details, see the tutorial.

Examples

>>> import xgi
>>> H = xgi.DiHypergraph([[{1, 2}, {5, 6}], [{4}, {1, 3}]])
>>> H.degree()
{1: 2, 2: 1, 5: 1, 6: 1, 4: 1, 3: 1}
>>> H.nodes.degree.asdict()
{1: 2, 2: 1, 5: 1, 6: 1, 4: 1, 3: 1}

Functions

xgi.stats.dinodestats.attrs(net, bunch, attr=None, missing=None)[source]

Access node attributes.

Parameters:

  • net (xgi.Hypergraph) – The network.

  • bunch (Iterable) – Nodes in net.

  • attr (str | None (default)) – If None, return all attributes. Otherwise, return a single attribute with name attr.

  • missing (Any) – Value to impute in case a node does not have an attribute with name attr. Default is None.

Returns:

If attr is None, return a nested dict of the form {node: {“attr”: val}}. Otherwise, return a simple dict of the form {node: val}.

Return type:

dict

Notes

When requesting all attributes (i.e. when attr is None), no value is imputed.

Examples

>>> import xgi
>>> H = xgi.DiHypergraph()
>>> H.add_nodes_from([
...         (1, {"color": "red", "name": "horse"}),
...         (2, {"color": "blue", "name": "pony"}),
...         (3, {"color": "yellow", "name": "zebra"}),
...         (4, {"color": "red", "name": "orangutan", "age": 20}),
...         (5, {"color": "blue", "name": "fish", "age": 2}),
...     ])

Access all attributes as different types.

>>> H.nodes.attrs.asdict() 
{1: {'color': 'red', 'name': 'horse'},
 2: {'color': 'blue', 'name': 'pony'},
 3: {'color': 'yellow', 'name': 'zebra'},
 4: {'color': 'red', 'name': 'orangutan', 'age': 20},
 5: {'color': 'blue', 'name': 'fish', 'age': 2}}
>>> H.nodes.attrs.asnumpy() 
array([{'color': 'red', 'name': 'horse'},
       {'color': 'blue', 'name': 'pony'},
       {'color': 'yellow', 'name': 'zebra'},
       {'color': 'red', 'name': 'orangutan', 'age': 20},
       {'color': 'blue', 'name': 'fish', 'age': 2}],
      dtype=object)

Access a single attribute as different types.

>>> H.nodes.attrs('color').asdict()
{1: 'red', 2: 'blue', 3: 'yellow', 4: 'red', 5: 'blue'}
>>> H.nodes.attrs('color').aslist()
['red', 'blue', 'yellow', 'red', 'blue']

By default, None is imputed when a node does not have the requested attribute.

>>> H.nodes.attrs('age').asdict()
{1: None, 2: None, 3: None, 4: 20, 5: 2}

Use missing to change the imputed value.

>>> H.nodes.attrs('age', missing=100).asdict()
{1: 100, 2: 100, 3: 100, 4: 20, 5: 2}
xgi.stats.dinodestats.degree(net, bunch, order=None, weight=None)[source]

Node degree.

The degree of a node is the number of edges it belongs to, regardless of whether it is in the head or the tail.

Parameters:

  • net (xgi.Hypergraph) – The network.

  • bunch (Iterable) – Nodes in net.

  • order (int | None) – If not None (default), only count the edges of the given order.

  • weight (str | None) – If not None, specifies the name of the edge attribute that determines the weight of each edge.

Return type:

dict

Examples

>>> import xgi
>>> H = xgi.DiHypergraph([[{1, 2}, {5, 6}], [{4}, {1, 3}]])
>>> H.nodes.degree.asdict()
{1: 2, 2: 1, 5: 1, 6: 1, 4: 1, 3: 1}
xgi.stats.dinodestats.in_degree(net, bunch, order=None, weight=None)[source]

Node in-degree.

The in-degree of a node is the number of edges for which the node is in the head (it is a receiver).

Parameters:

  • net (xgi.Hypergraph) – The network.

  • bunch (Iterable) – Nodes in net.

  • order (int | None) – If not None (default), only count the edges of the given order.

  • weight (str | None) – If not None, specifies the name of the edge attribute that determines the weight of each edge.

Return type:

dict

Examples

>>> import xgi
>>> H = xgi.DiHypergraph([[{1, 2}, {5, 6}], [{4}, {1, 3}]])
>>> H.nodes.in_degree.asdict()
{1: 1, 2: 1, 5: 0, 6: 0, 4: 1, 3: 0}
xgi.stats.dinodestats.out_degree(net, bunch, order=None, weight=None)[source]

Node out-degree.

The out-degree of a node is the number of edges for which the node is in the tail (it is a sender).

Parameters:

  • net (xgi.Hypergraph) – The network.

  • bunch (Iterable) – Nodes in net.

  • order (int | None) – If not None (default), only count the edges of the given order.

  • weight (str | None) – If not None, specifies the name of the edge attribute that determines the weight of each edge.

Return type:

dict

Examples

>>> import xgi
>>> H = xgi.DiHypergraph([[{1, 2}, {5, 6}], [{4}, {1, 3}]])
>>> H.nodes.out_degree.asdict()
{1: 1, 2: 0, 5: 1, 6: 1, 4: 0, 3: 1}