def test_bounding_circle(self):
def circle_num_points(num_seg):
# num_seg is the number of segments per quarter circle.
return (4 * num_seg) + 1
expected_areas = (169, 136) if postgis else (171, 126)
qs = Country.objects.annotate(
circle=functions.BoundingCircle('mpoly')).order_by('name')
self.assertAlmostEqual(qs[0].circle.area, expected_areas[0], 0)
self.assertAlmostEqual(qs[1].circle.area, expected_areas[1], 0)
if postgis:
# By default num_seg=48.
self.assertEqual(qs[0].circle.num_points, circle_num_points(48))
self.assertEqual(qs[1].circle.num_points, circle_num_points(48))
qs = Country.objects.annotate(circle=functions.BoundingCircle(
'mpoly', num_seg=12)).order_by('name')
if postgis:
self.assertGreater(qs[0].circle.area, 168.4, 0)
self.assertLess(qs[0].circle.area, 169.5, 0)
self.assertAlmostEqual(qs[1].circle.area, 136, 0)
self.assertEqual(qs[0].circle.num_points, circle_num_points(12))
self.assertEqual(qs[1].circle.num_points, circle_num_points(12))
else:
self.assertAlmostEqual(qs[0].circle.area, expected_areas[0], 0)
self.assertAlmostEqual(qs[1].circle.area, expected_areas[1], 0)
def test_bounding_circle(self):
def circle_num_points(num_seg):
# num_seg is the number of segments per quarter circle.
return (4 * num_seg) + 1
expected_areas = (169, 136) if connection.ops.postgis else (171, 126)
qs = Country.objects.annotate(
circle=functions.BoundingCircle("mpoly")).order_by("name")
self.assertAlmostEqual(qs[0].circle.area, expected_areas[0], 0)
self.assertAlmostEqual(qs[1].circle.area, expected_areas[1], 0)
if connection.ops.postgis:
# By default num_seg=48.
self.assertEqual(qs[0].circle.num_points, circle_num_points(48))
self.assertEqual(qs[1].circle.num_points, circle_num_points(48))
tests = [12, Value(12, output_field=IntegerField())]
for num_seq in tests:
with self.subTest(num_seq=num_seq):
qs = Country.objects.annotate(circle=functions.BoundingCircle(
"mpoly", num_seg=num_seq), ).order_by("name")
if connection.ops.postgis:
self.assertGreater(qs[0].circle.area, 168.4, 0)
self.assertLess(qs[0].circle.area, 169.5, 0)
self.assertAlmostEqual(qs[1].circle.area, 136, 0)
self.assertEqual(qs[0].circle.num_points,
circle_num_points(12))
self.assertEqual(qs[1].circle.num_points,
circle_num_points(12))
else:
self.assertAlmostEqual(qs[0].circle.area,
expected_areas[0], 0)
self.assertAlmostEqual(qs[1].circle.area,
expected_areas[1], 0)
def test_bounding_circle(self):
qs = Country.objects.annotate(circle=functions.BoundingCircle('mpoly')).order_by('name')
self.assertAlmostEqual(qs[0].circle.area, 168.89, 2)
self.assertAlmostEqual(qs[1].circle.area, 135.95, 2)
qs = Country.objects.annotate(circle=functions.BoundingCircle('mpoly', num_seg=12)).order_by('name')
self.assertAlmostEqual(qs[0].circle.area, 168.44, 2)
self.assertAlmostEqual(qs[1].circle.area, 135.59, 2)
def test_bounding_circle(self):
# The weak precision in the assertions is because the BoundingCircle
# calculation changed on PostGIS 2.3.
qs = Country.objects.annotate(
circle=functions.BoundingCircle('mpoly')).order_by('name')
self.assertAlmostEqual(qs[0].circle.area, 169, 0)
self.assertAlmostEqual(qs[1].circle.area, 136, 0)
qs = Country.objects.annotate(circle=functions.BoundingCircle(
'mpoly', num_seg=12)).order_by('name')
self.assertGreater(qs[0].circle.area, 168.4, 0)
self.assertLess(qs[0].circle.area, 169.5, 0)
self.assertAlmostEqual(qs[1].circle.area, 136, 0)