momepy.cyclomatic

momepy.cyclomatic(graph, radius=5, name='cyclomatic', distance=None)[source]

Calculates cyclomatic complexity for subgraph around each node if radius is set, or for whole graph, if radius=None.

Subgraph is generated around each node within set radius. If distance=None, radius will define topological distance, otherwise it uses values in distance attribute.

\[\alpha=e-v+1\]

where \(e\) is the number of edges in subgraph and \(v\) is the number of nodes in subgraph.

Adapted from [BSN12].

Parameters
graphnetworkx.Graph

Graph representing street network. Ideally generated from GeoDataFrame using momepy.gdf_to_nx()

radius: int

Include all neighbors of distance <= radius from n

namestr, optional

calculated attribute name

distancestr, optional

Use specified edge data key as distance. For example, setting distance=’weight’ will use the edge weight to measure the distance from the node n.

Returns
Graph

networkx.Graph if radius is set

float

cyclomatic complexity for graph if radius=None

Examples

>>> network_graph = mm.cyclomatic(network_graph, radius=3)