momepy.gamma(graph, radius=5, name='gamma', distance=None, verbose=True)[source]#

Calculates connectivity gamma index for subgraph around each node if radius is set, or for whole graph, if radius=None. A subgraph is generated around each node within set radius. If distance=None, radius will define topological distance, otherwise it uses values in distance attribute.


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

Adapted from [Dibble et al., 2017].


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

radius: int

Include all neighbors of distance <= radius from n.

namestr, optional

The 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.

verbosebool (default True)

If True, shows progress bars in loops and indication of steps.


A networkx.Graph object if radius is set.


The gamma index for the graph if radius=None.


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