Graph

distance

pytrack.graph.distance.add_edge_lengths(G, precision=3)[source]

Method that adds the length of individual edges to the graph.

Parameters

  • G (networkx.MultiDiGraph) – Road network graph.

  • precision (float, optional, default: 3) – Number of decimal digits of the length of individual edges.

Returns

G – Street network graph.

Return type

networkx.MultiDiGraph

pytrack.graph.distance.enlarge_bbox(north, south, west, east, dist)[source]

Method that expands a bounding box by a specified distance.

Parameters

  • north (float) – Northern latitude of bounding box.

  • south (float) – Southern latitude of bounding box.

  • west (float) – Western longitude of bounding box.

  • east (float) – Eastern longitude of bounding box.

  • dist (float) – Distance in meters indicating how much to expand the bounding box.

Returns

north, south, west, east – North, south, west, east coordinates of the expanded bounding box

Return type

float

pytrack.graph.distance.get_bearing(lat1, lon1, lat2, lon2)[source]

Get bearing between two points.

Parameters

  • lat1 (float) – Latitude of the first point specified in decimal degrees

  • lon1 (float) – Longitude of the first point specified in decimal degrees

  • lat2 (float) – Latitude of the second point specified in decimal degrees

  • lon2 (float) – Longitude of the second point specified in decimal degrees

Returns

bearing – Bearing between two points.

Return type

float

pytrack.graph.distance.haversine_dist(lat1, lon1, lat2, lon2, earth_radius=6371009)[source]

Calculate the great circle distance between two points on the earth (specified in decimal degrees)

Parameters

  • lat1 (float) – Latitude of the first point specified in decimal degrees

  • lon1 (float) – Longitude of the first point specified in decimal degrees

  • lat2 (float) – Latitude of the second point specified in decimal degrees

  • lon2 (float) – Longitude of the second point specified in decimal degrees

  • earth_radius (float, optional, default: 6371009.0 meters) – Earth’s radius

Returns

dist – Distance in units of earth_radius

Return type

float

pytrack.graph.distance.interpolate_geom(geom, dist=1)[source]

Method that interpolates a geometry created using the shapely.geometry.LineString method.

Parameters

  • geom (shapely.geometry.LineString) – Geometry to be interpolated.

  • dist (float, optional, default: 1) – Distance between one node and the next.

Returns

geom – Interpolated geometry.

Return type

shapely.geometry

pytrack.graph.distance.interpolate_graph(G, dist=1)[source]

Method that creates a graph by interpolating the nodes of a graph.

Parameters

  • G (networkx.MultiDiGraph) – Road network graph.

  • dist (float, optional, default: 1) – Distance between one node and the next.

Returns

G – Street network graph.

Return type

networkx.MultiDiGraph

download

pytrack.graph.download.get_filters(network_type='drive')[source]

Get the filters with which to interrogate the OpenStreetMao API service.

Parameters

network_type (str, optional, default: 'drive') – Type of street network to obtain.

Returns

osm_filters – Filters identifying the type of road network to be obtained

Return type

str

pytrack.graph.download.osm_download(bbox, network_type='drive', custom_filter=None)[source]

Get the OpenStreetMap response.

Parameters

  • bbox (tuple) – bounding box within N, S, E, W coordinates.

  • network_type (str, optional, default: 'drive') – Type of street network to obtain.

  • custom_filter (str or None, optional, default: None) – Custom filter to be used instead of the predefined ones to query the Overpass API. An example of a custom filter is the following ‘[highway][!”footway”]’. For more information visit https://overpass-turbo.eu and https://taginfo.openstreetmap.org.

Returns

response – Response of the OpenStreetMao API service.

Return type

json

graph

pytrack.graph.graph.add_edges(G, paths, bidirectional=False, all_oneway=False)[source]

Add OSM edges to a networkx.MultiDiGraph.

Parameters

  • G (networkx.MultiDiGraph) – Street network graph.

  • paths (dict) – Dictionary of OSM paths.

  • bidirectional (bool, optional, default: False) – Indicates whether an edge is bidirectional.

  • all_oneway (bool, optional, default: False) – Indicates whether an edge is oneway.

pytrack.graph.graph.convert_edge(element)[source]

Convert an OSM edge into an edge to construct a street network graph.

Parameters

element (dict) – An OSM path.

Returns

path – Dictionary for an OSM path.

Return type

dict

pytrack.graph.graph.convert_node(element)[source]

Convert an OSM node into a node to construct a street network graph.

Parameters

element (dict) – An OSM node.

Returns

path – Dictionary for an OSM node.

Return type

dict

pytrack.graph.graph.create_graph(response_json)[source]

Method that creates a networkx.MultiDiGraph representing a network street graph.

Parameters

response_json (json) – Response of OpenStreetMap API service got with``osm_download``method.

Returns

G – Street network graph.

Return type

networkx.MultiDiGraph

pytrack.graph.graph.get_nodes_edges(response_json)[source]

Extract nodes and paths from the OpenStreetMap query response.

Parameters

response_json (json) – Response of OpenStreetMap API service got with``osm_download``method

Returns

  • nodes (dict) – Dictionary of OSM nodes.

  • paths (dict) – Dictionary of OSM paths.

pytrack.graph.graph.graph_from_bbox(north, south, west, east, simplify=True, network_type='drive', custom_filter=None, buffer_dist=0)[source]

Create a graph from OpenStreetMap within some bounding box.

Parameters

  • north (float) – Northern latitude of bounding box.

  • south (float) – southern latitude of bounding box.

  • west (float) – Western longitude of bounding box.

  • east (float) – Eastern longitude of bounding box.

  • simplify (bool, optional, default: True) – if True, simplify graph topology with the simplify_graph method.

  • network_type (str, optional, default: 'drive') – Type of street network to obtain.

  • custom_filter (str or None, optional, default: None) – Custom filter to be used instead of the predefined ones to query the Overpass API.

  • buffer_dist (float, optional, default: 0) – Distance in meters indicating how much to expand the bounding box.

Returns

G – Street network graph.

Return type

networkx.MultiDiGraph

utils

pytrack.graph.utils.get_unique_number(lon, lat)[source]

Assigns a unique identifier to a geographical coordinate. :param lon: Longitude of the point :type lon: float :param lat: Latitude of the point :type lat: float

Returns

val – Unique identifier.

Return type

float

pytrack.graph.utils.graph_to_gdfs(G, nodes=True, edges=True, node_geometry=True, edge_geometry=True)[source]

Convert a networkx.MultiDiGraph to node and/or edge pandas DataFrame.

Parameters

  • G (networkx.MultiDiGraph) – Street network graph.

  • nodes (bool, optional, default: True) – Whether to extract graph nodes.

  • edges (bool, optional, default: True) – Whether to extract graph edges.

  • node_geometry (bool, optional, default: True) – Whether to compute graph node geometries.

  • edge_geometry (bool, optional, default: True) – Whether to extract graph edge geometries.

Returns

  • gdf_nodes (pandas.DataFrame) – Dataframe collecting graph nodes.

  • gdf_edges (pandas.DataFrame) – Dataframe collecting graph edges