def test_radius_too_small(self):
"""
Tests the function factor_polygon_into_circles for a radius of 10 m.
"""
coord = ((0.0, -0.01), (0.0, 0.01),
(0.025, 0.01), (0.05, -0.01), (0.0, -0.01))
radius_km = 0.01
with self.assertRaises(ValueError):
polygon = Polygon(coord)
shapes.factor_polygon_into_circles(polygon, radius_km)
def factor_by_radius_km(self, radius_km):
"""
Takes a Location and a radius in kilometers. Returns a list of Locations
representing circles of the specified radius that together cover the
area of the original Location.
"""
assert self.shape != 'Other', 'Shape must be Point, Polygon, or ' + \
'Muiltpolygon'
polygon = self.bbox
points = shapes.factor_polygon_into_circles(polygon, radius_km)
radius = units.km_to_meters(radius_km)
return [self._create_radius(point, radius) for point in points]
def _process_parameters(self, coord, radius_m):
"""
Helper function to process test parameters through
the factor_polygon_into_circles function.
"""
radius_km = units.meters_to_km(radius_m)
polygon = Polygon(coord)
points = shapes.factor_polygon_into_circles(polygon, radius_km)
# take the generated points and turn them into "circles" (polygons)
radius_in_deg = units.convert_meters_to_degrees(radius_m)
circles = [Point(point).buffer(radius_in_deg) for point in points]
# convert the list of circles into a multipolyon and merge them
merged_circles = MultiPolygon(circles).cascaded_union
# make sure the merged circles have no holes and completely cover
# the original polygon
self.assertTrue(merged_circles.num_interior_rings == 0,
'The merged circles had %s holes but should have none'
% merged_circles.num_interior_rings)
self.assertTrue(merged_circles.prepared.covers(polygon),
'The merged circles do not cover the polygon')