from django.contrib.gis.db.models.functions import (
Area,
Distance,
Length,
Perimeter,
Transform,
Union,
)
from django.contrib.gis.geos import GEOSGeometry, LineString, Point
from django.contrib.gis.measure import D # alias for Distance
from django.db import NotSupportedError, connection
from django.db.models import (
Case,
Count,
Exists,
F,
IntegerField,
OuterRef,
Q,
Value,
When,
)
from django.test import TestCase, skipIfDBFeature, skipUnlessDBFeature
from ..utils import FuncTestMixin
from .models import (
AustraliaCity,
CensusZipcode,
Interstate,
SouthTexasCity,
SouthTexasCityFt,
SouthTexasInterstate,
SouthTexasZipcode,
)
class DistanceTest(TestCase):
fixtures = ["initial"]
def setUp(self):
# A point we are testing distances with -- using a WGS84
# coordinate that'll be implicitly transformed to that to
# the coordinate system of the field, EPSG:32140 (Texas South Central
# w/units in meters)
self.stx_pnt = GEOSGeometry(
"POINT (-95.370401017314293 29.704867409475465)", 4326
)
# Another one for Australia
self.au_pnt = GEOSGeometry("POINT (150.791 -34.4919)", 4326)
def get_names(self, qs):
cities = [c.name for c in qs]
cities.sort()
return cities
def test_init(self):
"""
Test initialization of distance models.
"""
self.assertEqual(9, SouthTexasCity.objects.count())
self.assertEqual(9, SouthTexasCityFt.objects.count())
self.assertEqual(11, AustraliaCity.objects.count())
self.assertEqual(4, SouthTexasZipcode.objects.count())
self.assertEqual(4, CensusZipcode.objects.count())
self.assertEqual(1, Interstate.objects.count())
self.assertEqual(1, SouthTexasInterstate.objects.count())
@skipUnlessDBFeature("supports_dwithin_lookup")
def test_dwithin(self):
"""
Test the `dwithin` lookup type.
"""
# Distances -- all should be equal (except for the
# degree/meter pair in au_cities, that's somewhat
# approximate).
tx_dists = [(7000, 22965.83), D(km=7), D(mi=4.349)]
au_dists = [(0.5, 32000), D(km=32), D(mi=19.884)]
# Expected cities for Australia and Texas.
tx_cities = ["Downtown Houston", "Southside Place"]
au_cities = ["Mittagong", "Shellharbour", "Thirroul", "Wollongong"]
# Performing distance queries on two projected coordinate systems one
# with units in meters and the other in units of U.S. survey feet.
for dist in tx_dists:
if isinstance(dist, tuple):
dist1, dist2 = dist
else:
dist1 = dist2 = dist
qs1 = SouthTexasCity.objects.filter(point__dwithin=(self.stx_pnt, dist1))
qs2 = SouthTexasCityFt.objects.filter(point__dwithin=(self.stx_pnt, dist2))
for qs in qs1, qs2:
with self.subTest(dist=dist, qs=qs):
self.assertEqual(tx_cities, self.get_names(qs))
# With a complex geometry expression
self.assertFalse(
SouthTexasCity.objects.exclude(point__dwithin=(Union("point", "point"), 0))
)
# Now performing the `dwithin` queries on a geodetic coordinate system.
for dist in au_dists:
with self.subTest(dist=dist):
type_error = isinstance(dist, D) and not connection.ops.oracle
if isinstance(dist, tuple):
if connection.ops.oracle or connection.ops.spatialite:
# Result in meters
dist = dist[1]
else:
# Result in units of the field
dist = dist[0]
# Creating the query set.
qs = AustraliaCity.objects.order_by("name")
if type_error:
# A ValueError should be raised on PostGIS when trying to
# pass Distance objects into a DWithin query using a
# geodetic field.
with self.assertRaises(ValueError):
AustraliaCity.objects.filter(
point__dwithin=(self.au_pnt, dist)
).count()
else:
self.assertEqual(
au_cities,
self.get_names(qs.filter(point__dwithin=(self.au_pnt, dist))),
)
@skipUnlessDBFeature("supports_distances_lookups")
def test_distance_lookups(self):
# Retrieving the cities within a 20km 'donut' w/a 7km radius 'hole'
# (thus, Houston and Southside place will be excluded as tested in
# the `test02_dwithin` above).
for model in [SouthTexasCity, SouthTexasCityFt]:
stx_pnt = self.stx_pnt.transform(
model._meta.get_field("point").srid, clone=True
)
qs = model.objects.filter(point__distance_gte=(stx_pnt, D(km=7))).filter(
point__distance_lte=(stx_pnt, D(km=20)),
)
cities = self.get_names(qs)
self.assertEqual(cities, ["Bellaire", "Pearland", "West University Place"])
# Doing a distance query using Polygons instead of a Point.
z = SouthTexasZipcode.objects.get(name="77005")
qs = SouthTexasZipcode.objects.exclude(name="77005").filter(
poly__distance_lte=(z.poly, D(m=275))
)
self.assertEqual(["77025", "77401"], self.get_names(qs))
# If we add a little more distance 77002 should be included.
qs = SouthTexasZipcode.objects.exclude(name="77005").filter(
poly__distance_lte=(z.poly, D(m=300))
)
self.assertEqual(["77002", "77025", "77401"], self.get_names(qs))
@skipUnlessDBFeature("supports_distances_lookups", "supports_distance_geodetic")
def test_geodetic_distance_lookups(self):
"""
Test distance lookups on geodetic coordinate systems.
"""
# Line is from Canberra to Sydney. Query is for all other cities within
# a 100km of that line (which should exclude only Hobart & Adelaide).
line = GEOSGeometry("LINESTRING(144.9630 -37.8143,151.2607 -33.8870)", 4326)
dist_qs = AustraliaCity.objects.filter(point__distance_lte=(line, D(km=100)))
expected_cities = [
"Batemans Bay",
"Canberra",
"Hillsdale",
"Melbourne",
"Mittagong",
"Shellharbour",
"Sydney",
"Thirroul",
"Wollongong",
]
if connection.ops.spatialite:
# SpatiaLite is less accurate and returns 102.8km for Batemans Bay.
expected_cities.pop(0)
self.assertEqual(expected_cities, self.get_names(dist_qs))
msg = "2, 3, or 4-element tuple required for 'distance_lte' lookup."
with self.assertRaisesMessage(ValueError, msg): # Too many params.
len(
AustraliaCity.objects.filter(
point__distance_lte=(
"POINT(5 23)",
D(km=100),
"spheroid",
"4",
None,
)
)
)
with self.assertRaisesMessage(ValueError, msg): # Too few params.
len(AustraliaCity.objects.filter(point__distance_lte=("POINT(5 23)",)))
msg = "For 4-element tuples the last argument must be the 'spheroid' directive."
with self.assertRaisesMessage(ValueError, msg):
len(
AustraliaCity.objects.filter(
point__distance_lte=("POINT(5 23)", D(km=100), "spheroid", "4")
)
)
# Getting all cities w/in 550 miles of Hobart.
hobart = AustraliaCity.objects.get(name="Hobart")
qs = AustraliaCity.objects.exclude(name="Hobart").filter(
point__distance_lte=(hobart.point, D(mi=550))
)
cities = self.get_names(qs)
self.assertEqual(cities, ["Batemans Bay", "Canberra", "Melbourne"])
# Cities that are either really close or really far from Wollongong --
# and using different units of distance.
wollongong = AustraliaCity.objects.get(name="Wollongong")
d1, d2 = D(yd=19500), D(nm=400) # Yards (~17km) & Nautical miles.
# Normal geodetic distance lookup (uses `distance_sphere` on PostGIS.
gq1 = Q(point__distance_lte=(wollongong.point, d1))
gq2 = Q(point__distance_gte=(wollongong.point, d2))
qs1 = AustraliaCity.objects.exclude(name="Wollongong").filter(gq1 | gq2)
# Geodetic distance lookup but telling GeoDjango to use `distance_spheroid`
# instead (we should get the same results b/c accuracy variance won't matter
# in this test case).
querysets = [qs1]
if connection.features.has_DistanceSpheroid_function:
gq3 = Q(point__distance_lte=(wollongong.point, d1, "spheroid"))
gq4 = Q(point__distance_gte=(wollongong.point, d2, "spheroid"))
qs2 = AustraliaCity.objects.exclude(name="Wollongong").filter(gq3 | gq4)
querysets.append(qs2)
for qs in querysets:
cities = self.get_names(qs)
self.assertEqual(cities, ["Adelaide", "Hobart", "Shellharbour", "Thirroul"])
@skipUnlessDBFeature("supports_distances_lookups")
def test_distance_lookups_with_expression_rhs(self):
stx_pnt = self.stx_pnt.transform(
SouthTexasCity._meta.get_field("point").srid, clone=True
)
qs = SouthTexasCity.objects.filter(
point__distance_lte=(stx_pnt, F("radius")),
).order_by("name")
self.assertEqual(
self.get_names(qs),
[
"Bellaire",
"Downtown Houston",
"Southside Place",
"West University Place",
],
)
# With a combined expression
qs = SouthTexasCity.objects.filter(
point__distance_lte=(stx_pnt, F("radius") * 2),
).order_by("name")
self.assertEqual(len(qs), 5)
self.assertIn("Pearland", self.get_names(qs))
# With spheroid param
if connection.features.supports_distance_geodetic:
hobart = AustraliaCity.objects.get(name="Hobart")
AustraliaCity.objects.update(ref_point=hobart.point)
for ref_point in [hobart.point, F("ref_point")]:
qs = AustraliaCity.objects.filter(
point__distance_lte=(ref_point, F("radius") * 70, "spheroid"),
).order_by("name")
self.assertEqual(
self.get_names(qs), ["Canberra", "Hobart", "Melbourne"]
)
# With a complex geometry expression
self.assertFalse(
SouthTexasCity.objects.filter(
point__distance_gt=(Union("point", "point"), 0)
)
)
self.assertEqual(
SouthTexasCity.objects.filter(
point__distance_lte=(Union("point", "point"), 0)
).count(),
SouthTexasCity.objects.count(),
)
@skipUnlessDBFeature("supports_distances_lookups")
def test_distance_annotation_group_by(self):
stx_pnt = self.stx_pnt.transform(
SouthTexasCity._meta.get_field("point").srid,
clone=True,
)
qs = (
SouthTexasCity.objects.annotate(
relative_distance=Case(
When(point__distance_lte=(stx_pnt, D(km=20)), then=Value(20)),
default=Value(100),
output_field=IntegerField(),
),
)
.values("relative_distance")
.annotate(count=Count("pk"))
)
self.assertCountEqual(
qs,
[
{"relative_distance": 20, "count": 5},
{"relative_distance": 100, "count": 4},
],
)
def test_mysql_geodetic_distance_error(self):
if not connection.ops.mysql:
self.skipTest("This is a MySQL-specific test.")
msg = (
"Only numeric values of degree units are allowed on geodetic distance "
"queries."
)
with self.assertRaisesMessage(ValueError, msg):
AustraliaCity.objects.filter(
point__distance_lte=(Point(0, 0), D(m=100))
).exists()
@skipUnlessDBFeature("supports_dwithin_lookup")
def test_dwithin_subquery(self):
"""dwithin lookup in a subquery using OuterRef as a parameter."""
qs = CensusZipcode.objects.annotate(
annotated_value=Exists(
SouthTexasCity.objects.filter(
point__dwithin=(OuterRef("poly"), D(m=10)),
)
)
).filter(annotated_value=True)
self.assertEqual(self.get_names(qs), ["77002", "77025", "77401"])
@skipUnlessDBFeature("supports_dwithin_lookup", "supports_dwithin_distance_expr")
def test_dwithin_with_expression_rhs(self):
# LineString of Wollongong and Adelaide coords.
ls = LineString(((150.902, -34.4245), (138.6, -34.9258)), srid=4326)
qs = AustraliaCity.objects.filter(
point__dwithin=(ls, F("allowed_distance")),
).order_by("name")
self.assertEqual(
self.get_names(qs),
["Adelaide", "Mittagong", "Shellharbour", "Thirroul", "Wollongong"],
)
@skipIfDBFeature("supports_dwithin_distance_expr")
def test_dwithin_with_expression_rhs_not_supported(self):
ls = LineString(((150.902, -34.4245), (138.6, -34.9258)), srid=4326)
msg = (
"This backend does not support expressions for specifying "
"distance in the dwithin lookup."
)
with self.assertRaisesMessage(NotSupportedError, msg):
list(
AustraliaCity.objects.filter(
point__dwithin=(ls, F("allowed_distance")),
)
)
"""
=============================
Distance functions on PostGIS
=============================
| Projected Geometry | Lon/lat Geometry | Geography (4326)
ST_Distance(geom1, geom2) | OK (meters) | :-( (degrees) | OK (meters)
ST_Distance(geom1, geom2, use_spheroid=False) | N/A | N/A | OK (meters), less accurate, quick
Distance_Sphere(geom1, geom2) | N/A | OK (meters) | N/A
Distance_Spheroid(geom1, geom2, spheroid) | N/A | OK (meters) | N/A
ST_Perimeter(geom1) | OK | :-( (degrees) | OK
================================
Distance functions on SpatiaLite
================================
| Projected Geometry | Lon/lat Geometry
ST_Distance(geom1, geom2) | OK (meters) | N/A
ST_Distance(geom1, geom2, use_ellipsoid=True) | N/A | OK (meters)
ST_Distance(geom1, geom2, use_ellipsoid=False) | N/A | OK (meters), less accurate, quick
Perimeter(geom1) | OK | :-( (degrees)
""" # NOQA
class DistanceFunctionsTests(FuncTestMixin, TestCase):
fixtures = ["initial"]
@skipUnlessDBFeature("has_Area_function")
def test_area(self):
# Reference queries:
# SELECT ST_Area(poly) FROM distapp_southtexaszipcode;
area_sq_m = [
5437908.90234375,
10183031.4389648,
11254471.0073242,
9881708.91772461,
]
# Tolerance has to be lower for Oracle
tol = 2
for i, z in enumerate(
SouthTexasZipcode.objects.annotate(area=Area("poly")).order_by("name")
):
self.assertAlmostEqual(area_sq_m[i], z.area.sq_m, tol)
@skipUnlessDBFeature("has_Distance_function")
def test_distance_simple(self):
"""
Test a simple distance query, with projected coordinates and without
transformation.
"""
lagrange = GEOSGeometry("POINT(805066.295722839 4231496.29461335)", 32140)
houston = (
SouthTexasCity.objects.annotate(dist=Distance("point", lagrange))
.order_by("id")
.first()
)
tol = 2 if connection.ops.oracle else 5
self.assertAlmostEqual(houston.dist.m, 147075.069813, tol)
@skipUnlessDBFeature("has_Distance_function", "has_Transform_function")
def test_distance_projected(self):
"""
Test the `Distance` function on projected coordinate systems.
"""
# The point for La Grange, TX
lagrange = GEOSGeometry("POINT(-96.876369 29.905320)", 4326)
# Reference distances in feet and in meters. Got these values from
# using the provided raw SQL statements.
# SELECT ST_Distance(
# point,
# ST_Transform(ST_GeomFromText('POINT(-96.876369 29.905320)', 4326), 32140)
# )
# FROM distapp_southtexascity;
m_distances = [
147075.069813,
139630.198056,
140888.552826,
138809.684197,
158309.246259,
212183.594374,
70870.188967,
165337.758878,
139196.085105,
]
# SELECT ST_Distance(
# point,
# ST_Transform(ST_GeomFromText('POINT(-96.876369 29.905320)', 4326), 2278)
# )
# FROM distapp_southtexascityft;
ft_distances = [
482528.79154625,
458103.408123001,
462231.860397575,
455411.438904354,
519386.252102563,
696139.009211594,
232513.278304279,
542445.630586414,
456679.155883207,
]
# Testing using different variations of parameters and using models
# with different projected coordinate systems.
dist1 = SouthTexasCity.objects.annotate(
distance=Distance("point", lagrange)
).order_by("id")
dist2 = SouthTexasCityFt.objects.annotate(
distance=Distance("point", lagrange)
).order_by("id")
dist_qs = [dist1, dist2]
# Ensuring expected distances are returned for each distance queryset.
for qs in dist_qs:
for i, c in enumerate(qs):
with self.subTest(c=c):
self.assertAlmostEqual(m_distances[i], c.distance.m, -1)
self.assertAlmostEqual(ft_distances[i], c.distance.survey_ft, -1)
@skipUnlessDBFeature("has_Distance_function", "supports_distance_geodetic")
def test_distance_geodetic(self):
"""
Test the `Distance` function on geodetic coordinate systems.
"""
# Testing geodetic distance calculation with a non-point geometry
# (a LineString of Wollongong and Shellharbour coords).
ls = LineString(((150.902, -34.4245), (150.87, -34.5789)), srid=4326)
# Reference query:
# SELECT ST_distance_sphere(
# point,
# ST_GeomFromText('LINESTRING(150.9020 -34.4245,150.8700 -34.5789)', 4326)
# )
# FROM distapp_australiacity ORDER BY name;
distances = [
1120954.92533513,
140575.720018241,
640396.662906304,
60580.9693849269,
972807.955955075,
568451.8357838,
40435.4335201384,
0,
68272.3896586844,
12375.0643697706,
0,
]
qs = AustraliaCity.objects.annotate(distance=Distance("point", ls)).order_by(
"name"
)
for city, distance in zip(qs, distances):
with self.subTest(city=city, distance=distance):
# Testing equivalence to within a meter (kilometer on SpatiaLite).
tol = -3 if connection.ops.spatialite else 0
self.assertAlmostEqual(distance, city.distance.m, tol)
@skipUnlessDBFeature("has_Distance_function", "supports_distance_geodetic")
def test_distance_geodetic_spheroid(self):
tol = 2 if connection.ops.oracle else 4
# Got the reference distances using the raw SQL statements:
# SELECT ST_distance_spheroid(
# point,
# ST_GeomFromText('POINT(151.231341 -33.952685)', 4326),
# 'SPHEROID["WGS 84",6378137.0,298.257223563]'
# )
# FROM distapp_australiacity WHERE (NOT (id = 11));
# SELECT ST_distance_sphere(
# point,
# ST_GeomFromText('POINT(151.231341 -33.952685)', 4326)
# )
# FROM distapp_australiacity WHERE (NOT (id = 11)); st_distance_sphere
spheroid_distances = [
60504.0628957201,
77023.9489850262,
49154.8867574404,
90847.4358768573,
217402.811919332,
709599.234564757,
640011.483550888,
7772.00667991925,
1047861.78619339,
1165126.55236034,
]
sphere_distances = [
60580.9693849267,
77144.0435286473,
49199.4415344719,
90804.7533823494,
217713.384600405,
709134.127242793,
639828.157159169,
7786.82949717788,
1049204.06569028,
1162623.7238134,
]
# Testing with spheroid distances first.
hillsdale = AustraliaCity.objects.get(name="Hillsdale")
qs = (
AustraliaCity.objects.exclude(id=hillsdale.id)
.annotate(distance=Distance("point", hillsdale.point, spheroid=True))
.order_by("id")
)
for i, c in enumerate(qs):
with self.subTest(c=c):
self.assertAlmostEqual(spheroid_distances[i], c.distance.m, tol)
if connection.ops.postgis or connection.ops.spatialite:
# PostGIS uses sphere-only distances by default, testing these as well.
qs = (
AustraliaCity.objects.exclude(id=hillsdale.id)
.annotate(distance=Distance("point", hillsdale.point))
.order_by("id")
)
for i, c in enumerate(qs):
with self.subTest(c=c):
self.assertAlmostEqual(sphere_distances[i], c.distance.m, tol)
@skipIfDBFeature("supports_distance_geodetic")
@skipUnlessDBFeature("has_Distance_function")
def test_distance_function_raw_result(self):
distance = (
Interstate.objects.annotate(
d=Distance(Point(0, 0, srid=4326), Point(0, 1, srid=4326)),
)
.first()
.d
)
self.assertEqual(distance, 1)
@skipUnlessDBFeature("has_Distance_function")
def test_distance_function_d_lookup(self):
qs = Interstate.objects.annotate(
d=Distance(Point(0, 0, srid=3857), Point(0, 1, srid=3857)),
).filter(d=D(m=1))
self.assertTrue(qs.exists())
@skipUnlessDBFeature("supports_tolerance_parameter")
def test_distance_function_tolerance_escaping(self):
qs = (
Interstate.objects.annotate(
d=Distance(
Point(500, 500, srid=3857),
Point(0, 0, srid=3857),
tolerance="0.05) = 1 OR 1=1 OR (1+1",
),
)
.filter(d=D(m=1))
.values("pk")
)
msg = "The tolerance parameter has the wrong type"
with self.assertRaisesMessage(TypeError, msg):
qs.exists()
@skipUnlessDBFeature("supports_tolerance_parameter")
def test_distance_function_tolerance(self):
# Tolerance is greater than distance.
qs = (
Interstate.objects.annotate(
d=Distance(
Point(0, 0, srid=3857),
Point(1, 1, srid=3857),
tolerance=1.5,
),
)
.filter(d=0)
.values("pk")
)
self.assertIs(qs.exists(), True)
@skipIfDBFeature("supports_distance_geodetic")
@skipUnlessDBFeature("has_Distance_function")
def test_distance_function_raw_result_d_lookup(self):
qs = Interstate.objects.annotate(
d=Distance(Point(0, 0, srid=4326), Point(0, 1, srid=4326)),
).filter(d=D(m=1))
msg = "Distance measure is supplied, but units are unknown for result."
with self.assertRaisesMessage(ValueError, msg):
list(qs)
@skipUnlessDBFeature("has_Distance_function", "has_Transform_function")
def test_distance_transform(self):
"""
Test the `Distance` function used with `Transform` on a geographic field.
"""
# We'll be using a Polygon (created by buffering the centroid
# of 77005 to 100m) -- which aren't allowed in geographic distance
# queries normally, however our field has been transformed to
# a non-geographic system.
z = SouthTexasZipcode.objects.get(name="77005")
# Reference query:
# SELECT ST_Distance(ST_Transform("distapp_censuszipcode"."poly", 32140),
# ST_GeomFromText('<buffer_wkt>', 32140))
# FROM "distapp_censuszipcode";
dists_m = [3553.30384972258, 1243.18391525602, 2186.15439472242]
# Having our buffer in the SRID of the transformation and of the field
# -- should get the same results. The first buffer has no need for
# transformation SQL because it is the same SRID as what was given
# to `transform()`. The second buffer will need to be transformed,
# however.
buf1 = z.poly.centroid.buffer(100)
buf2 = buf1.transform(4269, clone=True)
ref_zips = ["77002", "77025", "77401"]
for buf in [buf1, buf2]:
qs = (
CensusZipcode.objects.exclude(name="77005")
.annotate(distance=Distance(Transform("poly", 32140), buf))
.order_by("name")
)
self.assertEqual(ref_zips, sorted(c.name for c in qs))
for i, z in enumerate(qs):
self.assertAlmostEqual(z.distance.m, dists_m[i], 5)
@skipUnlessDBFeature("has_Distance_function")
def test_distance_order_by(self):
qs = (
SouthTexasCity.objects.annotate(
distance=Distance("point", Point(3, 3, srid=32140))
)
.order_by("distance")
.values_list("name", flat=True)
.filter(name__in=("San Antonio", "Pearland"))
)
self.assertSequenceEqual(qs, ["San Antonio", "Pearland"])
@skipUnlessDBFeature("has_Length_function")
def test_length(self):
"""
Test the `Length` function.
"""
# Reference query (should use `length_spheroid`).
# SELECT ST_length_spheroid(
# ST_GeomFromText('<wkt>', 4326)
# 'SPHEROID["WGS 84",6378137,298.257223563, AUTHORITY["EPSG","7030"]]'
# );
len_m1 = 473504.769553813
len_m2 = 4617.668
if connection.features.supports_length_geodetic:
qs = Interstate.objects.annotate(length=Length("path"))
tol = 2 if connection.ops.oracle else 3
self.assertAlmostEqual(len_m1, qs[0].length.m, tol)
# TODO: test with spheroid argument (True and False)
else:
# Does not support geodetic coordinate systems.
with self.assertRaises(NotSupportedError):
list(Interstate.objects.annotate(length=Length("path")))
# Now doing length on a projected coordinate system.
i10 = SouthTexasInterstate.objects.annotate(length=Length("path")).get(
name="I-10"
)
self.assertAlmostEqual(len_m2, i10.length.m, 2)
self.assertTrue(
SouthTexasInterstate.objects.annotate(length=Length("path"))
.filter(length__gt=4000)
.exists()
)
# Length with an explicit geometry value.
qs = Interstate.objects.annotate(length=Length(i10.path))
self.assertAlmostEqual(qs.first().length.m, len_m2, 2)
@skipUnlessDBFeature("has_Perimeter_function")
def test_perimeter(self):
"""
Test the `Perimeter` function.
"""
# Reference query:
# SELECT ST_Perimeter(distapp_southtexaszipcode.poly)
# FROM distapp_southtexaszipcode;
perim_m = [
18404.3550889361,
15627.2108551001,
20632.5588368978,
17094.5996143697,
]
tol = 2 if connection.ops.oracle else 7
qs = SouthTexasZipcode.objects.annotate(perimeter=Perimeter("poly")).order_by(
"name"
)
for i, z in enumerate(qs):
self.assertAlmostEqual(perim_m[i], z.perimeter.m, tol)
# Running on points; should return 0.
qs = SouthTexasCity.objects.annotate(perim=Perimeter("point"))
for city in qs:
self.assertEqual(0, city.perim.m)
@skipUnlessDBFeature("has_Perimeter_function")
def test_perimeter_geodetic(self):
# Currently only Oracle supports calculating the perimeter on geodetic
# geometries (without being transformed).
qs1 = CensusZipcode.objects.annotate(perim=Perimeter("poly"))
if connection.features.supports_perimeter_geodetic:
self.assertAlmostEqual(qs1[0].perim.m, 18406.3818954314, 3)
else:
with self.assertRaises(NotSupportedError):
list(qs1)
# But should work fine when transformed to projected coordinates
qs2 = CensusZipcode.objects.annotate(
perim=Perimeter(Transform("poly", 32140))
).filter(name="77002")
self.assertAlmostEqual(qs2[0].perim.m, 18404.355, 3)
@skipUnlessDBFeature(
"supports_null_geometries", "has_Area_function", "has_Distance_function"
)
def test_measurement_null_fields(self):
"""
Test the measurement functions on fields with NULL values.
"""
# Creating SouthTexasZipcode w/NULL value.
SouthTexasZipcode.objects.create(name="78212")
# Performing distance/area queries against the NULL PolygonField,
# and ensuring the result of the operations is None.
htown = SouthTexasCity.objects.get(name="Downtown Houston")
z = SouthTexasZipcode.objects.annotate(
distance=Distance("poly", htown.point), area=Area("poly")
).get(name="78212")
self.assertIsNone(z.distance)
self.assertIsNone(z.area)