diff options
Diffstat (limited to 'examples/geospatial')
| -rw-r--r-- | examples/geospatial/plot_osmnx.py | 46 |
1 files changed, 39 insertions, 7 deletions
diff --git a/examples/geospatial/plot_osmnx.py b/examples/geospatial/plot_osmnx.py index 1fedc352..86a51445 100644 --- a/examples/geospatial/plot_osmnx.py +++ b/examples/geospatial/plot_osmnx.py @@ -3,15 +3,47 @@ OSMnx ===== -This example shows how to read a shapefile with OSMnx -and convert it to a NetworkX graph.... +This example shows how to use OSMnx to download and model a street network +from OpenStreetMap, visualize centrality, and save the graph as a shapefile, +a GeoPackage, or GraphML. + +OSMnx is a Python package to retrieve, model, analyze, and visualize +OpenStreetMap street networks as NetworkX MultiDiGraph objects. It can also +retrieve any other spatial data from OSM as geopandas GeoDataFrames. See +https://osmnx.readthedocs.io/ for OSMnx documentation and usage. """ -import osmnx as ox import networkx as nx +import osmnx as ox + +ox.config(use_cache=True, log_console=True) + +# download street network data from OSM and construct a MultiDiGraph model +G = ox.graph_from_point((37.79, -122.41), dist=750, network_type="drive") + +# impute edge (driving) speeds and calculate edge traversal times +G = ox.add_edge_speeds(G) +G = ox.add_edge_travel_times(G) + +# you can convert MultiDiGraph to/from geopandas GeoDataFrames +gdf_nodes, gdf_edges = ox.graph_to_gdfs(G) +G = ox.graph_from_gdfs(gdf_nodes, gdf_edges, graph_attrs=G.graph) + +# convert MultiDiGraph to DiGraph to use nx.betweenness_centrality function +# choose between parallel edges by minimizing travel_time attribute value +D = ox.utils_graph.get_digraph(G, weight="travel_time") + +# calculate node betweenness centrality, weighted by travel time +bc = nx.betweenness_centrality(D, weight="travel_time", normalized=True) +nx.set_node_attributes(G, values=bc, name="bc") -# %% -# TODO +# plot the graph, coloring nodes by betweenness centrality +nc = ox.plot.get_node_colors_by_attr(G, "bc", cmap="plasma") +fig, ax = ox.plot_graph( + G, bgcolor="k", node_color=nc, node_size=50, edge_linewidth=2, edge_color="#333333" +) -G = ox.graph_from_point((37.79, -122.41), dist=750, network_type="all") -ox.plot_graph(G) +# save graph to shapefile, geopackage, or graphml +ox.save_graph_shapefile(G, filepath="./graph_shapefile/") +ox.save_graph_geopackage(G, filepath="./graph.gpkg") +ox.save_graphml(G, filepath="./graph.graphml") |