shapely_err.py

from shapely.geometry import LineString
import random


def get_coord_rand(prev=None):
    delta_lat = random.uniform(-0.1, 0.1)
    delta_lon = random.uniform(-0.1, 0.1)
    if delta_lat == 0.0 and delta_lon == 0.0:
        return get_coord_rand(prev)

    if prev is None:
        lat = random.uniform(-90.0, 90.0)
        lon = random.uniform(-180.0, 180.0)
        prev = (lon, lat)
    return (round(prev[0] + delta_lon, 6), round(prev[1] + delta_lat, 6))


def get_coord_static(prev=None):
    delta_lat = 1.0
    delta_lon = 0

    if prev is None:
        prev = (1, 1)
    return (round(prev[0] + delta_lon, 6), round(prev[1] + delta_lat, 6))


def find_noncrossing(prev_point, line_so_far, cord_gen):
    new_point = cord_gen(prev_point)
    new_segment = LineString([prev_point, new_point])
    intersects = line_so_far.intersects(new_segment)

    if not intersects:
        return new_point
    return find_noncrossing(prev_point, line_so_far, cord_gen)


def get_coord_no_cross(coords, cord_gen):

    prev_point = coords[-1] if len(coords) > 0 else None

    if len(coords) <= 2:
        return cord_gen(prev_point)

    line_so_far = LineString(coords[:-1])
    res = find_noncrossing(prev_point, line_so_far, cord_gen)
    line_so_far = None
    return res


def get_coords(num_coords, cord_gen):
    coords = []
    for i in range(0, num_coords):
        coords.append(get_coord_no_cross(coords, cord_gen))
    return coords

get_coords(100, get_coord_rand)  # ValueError: Prepared geometries cannot be operated on

get_coords(100, get_coord_static)  # ok!

get_coords(10, get_coord_rand)  # ok!

get_coords(10, get_coord_static)  # ok!