instances.city_graph¶

instances.city_graph(city, G=None, k=None, seed=None, request_nodes=None)[source]¶

Generate an OSMnx graph of city.

PDP graph contains k request pairs and an s and t node selected randomly from original OSMnx graph through the seed parameter.

Parameters:

city (str) – The city to query road network from. ‘City, Country’.
k (int) – 2 k + 2 is the number of nodes in graph. If None, default is 3 request pairs.
seed (int) – Seed for random graph generator. System time taken as default. H will always be the same, provided same G or city graph, k, and seed parameters.
request_nodes (list) – k + 1 pairs of origin-destination elements to include from G in H. (s, t) pair is 0th term and (o_i, d_i) pairs are remaining origin-destination pairs.

Returns:

G (graph) – OSMnx generated input graph of city.
H (graph) – Request graph version of G.

Examples

Query a city’s graph and make request graph a subgraph on 3 random request pairs set by the input seed.

>>> G, H = city_graph('Manhattan, USA', k=3, seed=23451)

Can also supply OSMnx graph G as a parameter in the case certain modifications were made by the user.

>>> import osmnx as ox
>>> G = ox.graph_from_place('Cornell University, USA', network_type='drive')
>>> G, H = city_graph('Cornell University, USA', G=G, k=5)