spherical_to_cartesian.py

# see https://en.wikipedia.org/wiki/Spherical_coordinate_system
def spherical_to_cartesian(lat, lon, radius):
    
    latitude = math.radians(lat)
    longitude = math.radians(lon)

    x = radius * math.sin(latitude) * math.cos(longitude)
    y = radius * math.sin(latitude) * math.sin(longitude)
    z = radius * math.cos(latitude)
    return x, y, z

''' example from the geojson dataset:

"type": "FeatureCollection",
"crs": { "type": "name", "properties": { "name": "urn:ogc:def:crs:OGC:1.3:CRS84" } },
                                                                                
"features": [
{ "type": "Feature", "properties": { "osm_id": "4245316", "code": 5115, "fclass": "tertiary", "name": "Corso Vittorio Emanuele II", "ref": null, "oneway": "F", "maxspeed": 50, "layer": "0", "bridge": "F", "tunnel": "F" }, "geometry": { "type": "MultiLineString", "coordinates": [ [ [ 12.4664084, 41.8995935 ], [ 12.4662495, 41.8997611 ] ] ] } },
'''