calculate_od_raw.py

calculateOD_gdf(G, origins, destinations, fail_value=-1, weight='time', calculate_snap=False, wgs84='epsg:4326')¶

Description:

Calculate Origin destination matrix from GeoDataframes

Parameters:

• G (networkx graph): describes the road network. Often extracted using OSMNX

• origins (geopandas dataframe): source locations for calculating access

• destinations (geopandas dataframe): destination locations for calculating access

• fail_value (optional):

• weight (optional):

• calculate_snap (boolean, optional): variable to add snapping distance to travel time, default is false

• wgs84 (CRS dictionary, optional): CRS of road network to which the GDFs are projected

Returns:

• numpy array: 2d OD matrix with columns as index of origins and rows as index of destinations

calculateOD_csv(G, originCSV, destinationCSV='', oLat='Lat', oLon='Lon', dLat='Lat', dLon='Lon', crs='epsg:4326', fail_value=-1, weight='time', calculate_snap=False)¶

Description:

Calculate OD matrix from csv files of points

Parameters:

• G: describes the road network. Often extracted using OSMNX

• originCSV:

• destinationCSV (optional):

• oLat (str, optional): Origin latitude field

• oLon (str, optional): Origin longitude field

• dLat (str, optional): Destination latitude field

• dLon (str, optional): Destination longitude field

• crs (str, optional): crs of input origins and destinations, defaults to ‘epsg:4326’

• fail_value (optional):

• weight (str, optional): variable in G used to define edge impedance, defaults to ‘time’

• calculate_snap (bool, optional): variable to add snapping distance to travel time, default is false

Returns:

• numpy array: 2d OD matrix with columns as index of origins and rows as index of destinations

calculate_gravity(od, oWeight=[], dWeight=[], decayVals=[0.01, 0.005, 0.001, 0.0007701635, 0.0003850818, 0.0001925409, 9.62704e-05, 3.85082e-05, 1e-05])¶

Description:

Calculate gravity model values for origin-destination (OD) matrix.

Parameters:

• od (numpy.ndarray): Origin-destination matrix.

• oWeight (list, optional): List of weights for each origin. Defaults to an empty list.

• dWeight (list, optional): List of weights for each destination. Defaults to an empty list.

• decayVals (list, optional): List of decay values for market access. Defaults to a predefined list.

Returns:

• pandas.DataFrame: DataFrame containing gravity model values for each origin-destination pair.