def circumcenter(*points, homogeneous=True):
"""Computes a circumcenter for a set of n+1 points in n dimensions,
ignoring the extended homogeneous coordinates.
Unless you pass homogeneous=False, the last coordinate of each
point will be lopped off. Behavior may not be defined if
any of the homogeneous coordinates is not 1.
"""
if homogeneous:
if [pt[-1] for pt in points] != [1] * len(points):
tmp = []
for v in [p.to_vector() for p in points]:
if v[-1] == 0:
v *= 1000000000
tmp.append(v)
# Just strip off the homogeneous coordinates.
tmp = [v[:-1] for v in tmp]
points = [Point(*v.to_array()) for v in tmp]
else:
points = [pt[:-1] for pt in points]
vectors = [p - points[0] for p in points[1:]]
A = Matrix(*vectors).transpose()
p0_squared = points[0].to_vector().norm_squared()
b = Vector(*[
0.5 * (p.to_vector().norm_squared() - p0_squared) for p in points[1:]
])
x = A.inverse() * b
# If the arguments had homogeneous coordinates, we want to tack the extra
# coordinate back on:
return Point(*x, *([1] if homogeneous else []))
def test_ccw_euclidean(self):
"""Right now this only tests ccw for 1 and 2 dimensions."""
# one-dimensional test.
one_dim_high = Point(1)
one_dim_low = Point(0)
# I don't much care which way is negative, but one had better be
# positive and the other negative. And they'd better be ints. (Of
# course, ccw in 1D is equivalent to numeric comparison.)
self.assertEqual((ccw(one_dim_high, one_dim_low, homogeneous=False) *
ccw(one_dim_low, one_dim_high, homogeneous=False)),
-1)
self.assertIsInstance((ccw(one_dim_high, one_dim_low,
homogeneous=False) *
ccw(one_dim_low, one_dim_high,
homogeneous=False)),
int)
# co-hyperplanar --> 0
self.assertEqual(ccw(one_dim_high, one_dim_high, homogeneous=False), 0)
# Now for 2D stuff:
# Invariance under rotation of args
self.assertEqual(ccw(self.r2north, self.r2east, self.r2south,
homogeneous=False),
ccw(self.r2south, self.r2north, self.r2east,
homogeneous=False))
self.assertEqual(ccw(self.r2north, self.r2east, self.r2south,
homogeneous=False), -1)
self.assertEqual(ccw(self.r2east, self.r2south, self.r2west,
homogeneous=False), -1)
self.assertEqual(ccw(self.r2south, self.r2north, self.r2orig,
homogeneous=False), 0)
self.assertEqual(ccw(self.r2east, self.r2orig, self.r2east,
homogeneous=False), 0)
self.assertEqual(ccw(self.r2west, self.r2east, self.r2south,
homogeneous=False), -1)
self.assertEqual(ccw(self.r2west, self.r2south, self.r2north,
homogeneous=False), 1)
# Swapping two args flips the sign
self.assertEqual(ccw(self.r2west, self.r2south, self.r2north,
homogeneous=False),
-ccw(self.r2south, self.r2west, self.r2north,
homogeneous=False))
self.assertEqual(ccw(self.r2west, self.r2east, self.r2orig,
homogeneous=False),
-ccw(self.r2east, self.r2west, self.r2orig,
homogeneous=False))
# Warn us when we make non-square matrices
self.assertRaises(Exception, ccw, self.r2west, self.r2south,
self.r2north, self.r2east, homogeneous=False)
self.assertRaises(Exception, ccw, self.r2orig, self.r2south,
homogeneous=False)
def test_lift(self):
"""Make sure lifting works nicely."""
# Define a function to use for testing
def f(x):
return x[0] * 2
self.assertTrue(self.b.lift(f) == Point(1, 2, 2))
self.assertFalse(self.c.lift(f) == Point(1, 2, 3, 4))
self.assertFalse(self.c.lift(f) == Point(1, 2, 3))
# Make sure that lifting a Point returns a Point
self.assertIsInstance(self.b.lift(f), Point)
def test_hashing(self):
"""Make sure point hashing works and does not cause collisions"""
# Add 400 points' hashes to a set and make sure 400 things are in the
# set
some_hashes = set()
for x in range(-10, 10):
for y in range(-10, 10):
some_hashes.add(hash(Point(x, y, 1)))
self.assertEqual(len(some_hashes), 400)
self.assertEqual(hash(Point(0, 1, 2)),
hash(Point(0, 1, 2)))
def test_in_general_position(self):
"""Test rigorously, but only for nice inputs"""
points = [
Point(0.5, -400, 1),
Point(10, 21, 1),
Point(-5, 0, 1),
Point(1, 2, 1),
Point(2, 1, 1)
]
deltri = DelT(points, randomize=False)
self.assertTrue(deltri.test_is_delaunay())
def test_2d_case(self):
"""Test the output for a super simple 2D case"""
del_tri = DelT([Point(3, 4), Point(-3, 4),
Point(0, -5)],
homogeneous=False,
randomize=False)
vor = Voronoi(del_tri)
expected_center = Point(0.0, 0.0, 1.0)
self.assertTrue(expected_center in vor.points)
self.assertTrue(len(vor.points) == 1)
self.assertTrue(len(vor.edges) == 3)
def test_misc_niceties(self):
"""I don't want the empty point to be a thing. You may disagree."""
with self.assertRaises(ValueError):
Point() # Try to make an empty point.
# Make sure that we can evaluate a point to True
self.assertTrue(self.a)
def ccw(*points, homogeneous=True):
"""tests if triangle a, b, c is oriented counterclockwise.
Returns 1 if ccw, 0 if colinear, -1 if cw.
Also does the scary analogous n-dimensional test, which
essentially tests if, from the perspective of the last point,
the other points appear to be well-oriented according
to the (n-1)-dimensional test.
"""
if not homogeneous:
mtrx = Matrix(*[pt.lift(lambda v: 1).to_vector() for pt in points])
else:
mtrx = None
for pt in points:
if pt[-1] == 1:
# We need at list one non-infinite point
# for this to work normally
mtrx = Matrix(*[pt.to_vector() for pt in points])
break
if mtrx is not None:
return mtrx.sign_det()
# If all points have 0 for extended homogeneous coordinate,
# win by using the ccw test for one dimension higher:
return ccw(*points,
Point(*(0 for i in range(len(points[0]) - 1)), -1),
homogeneous=False)
def __init__(self, triangulation):
self.points = set()
self.edges = set()
finite_faces = (f for f in triangulation.faces if self._is_finite(f))
for face in finite_faces:
point = circumcenter(*face.points())
self.points.add(point)
for half_facet in face.iter_facets():
if half_facet.twin:
adj_point = circumcenter(*half_facet.twin.face.points())
if not self._is_finite(half_facet.twin.face):
tmp_vec = ((adj_point.to_vector()[:-1]) *
(1 / 1000000000))
adj_point = Point(*tmp_vec.to_array())
adj_point = adj_point.lift(lambda *args: 0)
self.edges.add(frozenset([point, adj_point]))
def setUp(self):
"""Make some objects that are useful for most tests."""
# Make points on the unit circle in the plane
# North, East, South, and West shouldn't bend your brain
self.r2north = Point(0, 1)
self.r2south = Point(0, -1)
self.r2east = Point(1, 0)
self.r2west = Point(-1, 0)
self.r2orig = Point(0, 0)
# Now the homogeneous version of the same thing (We use the plane z=1
# to represent the plane R^2 but with a boundary (homeomorphic to a
# circle). Points with z=0 are essentially infinitely far away. The
# same idea works in higher dimensions.
self.homo_north = Point(0, 1, 1)
self.homo_south = Point(0, -1, 1)
self.homo_east = Point(1, 0, 1)
self.homo_west = Point(-1, 0, 1)
self.homo_orig = Point(0, 0, 1)
def outer_face_pts(dimension):
"""Get some points whose simplex contains all of R^{dimension}
This ought to be a triangulation method, I guess.
But I'm leaving it here for now.
(This is all the standard basis vectors, plus the vector of all -1s. Er,
but points, not vectors.)
"""
coords = [0] * (dimension + 1)
results = []
for i in range(dimension):
# Generate a standard basis vector
coords[i] = 1
results.append(Point(*coords))
coords[i] = 0
results.append(Point(*(-1 for i in range(dimension)), 0))
return results
def test_vertex_compare(self):
"""Make sure vertices have an order that's reasonable."""
verts = []
for i in range(-5, 5):
for j in range(-5, 5):
verts.append(DelT.Vertex(Point(i, j, 1)))
self.assertEqual(sorted(verts), sorted(verts[::-1])) # consistency
self.assertEqual(sorted(verts), sorted(verts))
self.assertLess(sorted(verts)[0], sorted(verts)[1])
self.assertNotEqual(verts[0], verts[1])
self.assertEqual(verts[0], verts[0])
def test_point_equal(self):
"""Tests if comparison of points for equality works"""
self.assertTrue(Point(0, -9, 11.2) == Point(0, -9, 11.2))
self.assertFalse(Point(0, -9, 1600002) == Point(0, -8, 1600002))
# Different location
self.assertFalse(Point(1, 4) == Point(1, 4, 5))
# Drew's tests:
self.assertFalse(self.a == self.b)
self.assertTrue(self.b == self.b)
self.assertTrue(Point(1, 2, 3) == Point(1, 2, 3))
self.assertFalse(self.b == self.c)
self.assertFalse(self.b == (1, 2))
def test_incircle_euclidean(self):
"""Test the incircle predicate in the plane."""
a = Point(1, 0)
b = Point(0, 1)
c = Point(-1, 0)
d = Point(0, 0)
self.assertTrue(incircle(a, b, c, d, homogeneous=False) == 1)
self.assertTrue(incircle(a, b, d, c, homogeneous=False) == -1)
self.assertTrue(incircle(a, b, c, c, homogeneous=False) == 0)
r2far_east = Point(50, -0.5)
# circle of radius 0... ought to be 0 (co-circular)
self.assertEqual(incircle(self.r2east, self.r2east, self.r2east,
self.r2east, homogeneous=False), 0)
# The origin is in fact inside the (counterclockwise) unit circle
self.assertEqual(incircle(self.r2east, self.r2north, self.r2west,
self.r2orig, homogeneous=False), 1)
# SHOULD depend on orientation of circle, so we can
# have stuff like inside-out circles
self.assertNotEqual(incircle(self.r2east, self.r2west, self.r2north,
self.r2orig, homogeneous=False),
incircle(self.r2west, self.r2east, self.r2north,
self.r2orig, homogeneous=False))
self.assertNotEqual(incircle(self.r2east, self.r2north, self.r2west,
self.r2orig, homogeneous=False),
incircle(self.r2north, self.r2east, self.r2west,
self.r2orig, homogeneous=False))
# Finitely faraway pt not in (counterclockwise) unit circle
self.assertEqual(incircle(self.r2north, self.r2west, self.r2east,
r2far_east, homogeneous=False), -1)
# Finitely faraway pt is in the clockwise (inside-out) unit circle
self.assertEqual(incircle(self.r2west, self.r2north, self.r2east,
r2far_east, homogeneous=False), 1)
def test_easy_peasy_case(self):
"""Test with one point and see if the structure makes sense."""
point = Point(-3, 2, 1)
deltri = DelT([point])
self.assertEqual(len(deltri.faces), 3)
for face in deltri.faces:
self.assertIn(point, face.points())
for hafacet in face.half_facets.values():
self.assertNotIn(hafacet.opposite, hafacet.points())
null_twin_count = 0
for face in deltri.faces:
self.assertEqual(len(face.vertices), 3)
for halffacet in face.half_facets.values():
if halffacet.twin is None:
null_twin_count += 1
else:
self.assertIs(halffacet.twin.twin, halffacet)
self.assertEqual(null_twin_count, 3)
self.assertTrue(deltri.test_is_delaunay())
def test_convex_hull_bug(self):
"""Eliminate bugs where the the convex hull becomes concave."""
# This case is prohibitively big to test properly
# points = [Point(*coords) for coords in [
# (248, 508, 1), (709, 346, 1), (820, 535, 1), (427, 274, 1),
# (671, 220, 1), (927, 342, 1), (612, 627, 1), (762, 633, 1),
# (161, 238, 1), (71, 102, 1), (185, 25, 1), (233, 6, 1)]]
# del_tri = DelT(points, homogeneous=True, randomize=False)
# self.assertTrue(del_tri.test_is_delaunay())
# A nice clean 4 points that caused a bug.
points = [
Point(*coords)
for coords in [(582, 245, 1), (649, 400, 1), (854, 279,
1), (411, 176, 1)]
]
del_tri = DelT(points, homogeneous=True, randomize=False)
self.assertEqual(len(del_tri.face_point_sets()), 3)
def test_3d_case(self):
fn = os.path.join(os.path.dirname(__file__), 'data/points.csv')
f = open(fn)
points = csv.reader(f)
points = list(points)
points = [[float(y) for y in x] for x in points]
point_array = [Point(*point) for point in points]
del_tri = DelT(point_array, homogeneous=False, randomize=False)
self.assertTrue(del_tri.test_is_delaunay())
face_sets = set([
frozenset(face)
for face in del_tri.face_point_sets(homogeneous=False)
])
fn = os.path.join(os.path.dirname(__file__), 'data/dt.csv')
with open(fn, 'r') as f:
triangles = list(csv.reader(f))
triangles = [[int(y) for y in x] for x in triangles]
expected_face_sets = set([
frozenset([point_array[y - 1] for y in x]) for x in triangles
])
for face_set in face_sets:
self.assertEqual(len(face_set), 4)
self.assertEqual(face_sets, expected_face_sets)
def test_2d_case(self):
"""Test the output for a 2D case transfered from a notebook"""
# First just make sure face equality works like I hope:
self.assertEqual(set(frozenset([Point(0, 3.7)])),
set(frozenset([Point(0, 3.7)])))
del_tri = DelT([
Point(-0.6, 3.2),
Point(3.2, 2.1),
Point(-2, 0),
Point(1, -0.2),
Point(3.6, -0.3),
Point(-1.4, -2.1),
Point(2.5, -1.7)
],
homogeneous=False,
randomize=False)
self.assertTrue(del_tri.test_is_delaunay())
face_sets = set([
frozenset(face)
for face in del_tri.face_point_sets(homogeneous=False)
])
expected_face_sets = set([
frozenset([Point(-2, 0),
Point(-0.6, 3.2),
Point(1, -0.2)]),
frozenset([Point(3.2, 2.1),
Point(-0.6, 3.2),
Point(1, -0.2)]),
frozenset([Point(3.2, 2.1),
Point(3.6, -0.3),
Point(1, -0.2)]),
frozenset([Point(2.5, -1.7),
Point(3.6, -0.3),
Point(1, -0.2)]),
frozenset([Point(2.5, -1.7),
Point(-1.4, -2.1),
Point(1, -0.2)]),
frozenset([Point(-1.4, -2.1),
Point(-2, 0),
Point(1, -0.2)])
])
# Note that equality of faces works exactly like you'd want. The test
# even nicely tells you the differences between the sets, if it fails.
for face_set in face_sets:
self.assertEqual(len(face_set), 3) # triangles have 3 vertices
self.assertEqual(face_sets, expected_face_sets)
def testCircumCenter(self):
"""Tests for the circumcenter utility"""
# Make sure the unit circle is centered at the origin
center1 = circumcenter(Point(1, 0),
Point(0, 1),
Point(0, -1),
homogeneous=False)
self.assertIsInstance(center1, Point)
self.assertEqual(center1, Point(0, 0))
# Do the same but with the unit sphere in R^3
center2 = circumcenter(Point(1, 0, 0),
Point(0, 1, 0),
Point(0, -1, 0),
Point(0, 0, 1),
homogeneous=False)
self.assertIsInstance(center2, Point)
self.assertEqual(center2, Point(0, 0, 0))
# Make sure it isn't just returning zero all the time
center3 = circumcenter(Point(1, 2),
Point(2, 1),
Point(1, 0),
homogeneous=False)
self.assertEqual(center3, Point(1.0, 1.0))
# Now let's see how it deals with homogeneous coordinates
# Now make sure homogeneous coordinates are properly ignored
# if they are all 1. (But the point returned should be
# of the same dimension as the input.)
self.assertEqual(
circumcenter(Point(2, 3, 1), Point(3, 2, 1), Point(2, 1, 1)),
Point(2, 2, 1))
def test_incircle_homogeneous(self):
"""Tests incircle on points with homogeneous coordinates
(representing points in R^d but with a boundary)
"""
far_east_finite = Point(50, 0, 1)
far_east_infinite = Point(1, 0, 0)
# Counterclockwise circle around origin contains origin:
self.assertEqual(incircle(self.homo_east, self.homo_north,
self.homo_south, self.homo_orig), 1)
# But it shouldn't contain any faraway point:
self.assertEqual(incircle(self.homo_east, self.homo_north,
self.homo_south, far_east_finite), -1)
self.assertEqual(incircle(self.homo_east, self.homo_north,
self.homo_south, far_east_infinite), -1)
# And of course, another point on the unit circle should be cocircular:
self.assertEqual(incircle(self.homo_east, self.homo_north,
self.homo_south, self.homo_west), 0)
# Clockwise circle around origin does not contain origin:
self.assertEqual(incircle(self.homo_north, self.homo_east,
self.homo_south, self.homo_orig), -1)
# But it SHOULD contain faraway points:
self.assertEqual(incircle(self.homo_north, self.homo_east,
self.homo_south, far_east_finite), 1)
self.assertEqual(incircle(self.homo_north, self.homo_east,
self.homo_south, far_east_infinite), 1)
# Cocircular stuff should still be cocircular:
self.assertEqual(incircle(self.homo_north, self.homo_east,
self.homo_south, self.homo_west), 0)
# Check for subtle arithmetic errors:
self.assertEqual(incircle(Point(0, -10, 1),
Point(0, 0, 1),
Point(-0.001, 10, 1),
Point(-0.0005, 10, 1)),
-1)
# Counterclockwise infinite triangle contains everything
inf_triangle = [Point(1, 0, 0), Point(-1, 1, 0), Point(-1, -1, 0)]
self.assertEqual(incircle(*inf_triangle, Point(12, -14, 1)),
1)
self.assertEqual(incircle(*inf_triangle, Point(-1, 1, 1)),
1)
# Clockwise infinite triangle contains nothing
self.assertEqual(incircle(*inf_triangle[::-1], Point(12, -14, 1)),
-1)
self.assertEqual(incircle(*inf_triangle[::-1], Point(-1, 1, 1)),
-1)
# Tricky cases:
self.assertEqual(incircle(
Point(-1, -1, 0), Point(-3, 2, 1), Point(1, 0, 0), Point(0, 1, 0)),
1)
self.assertEqual(incircle(
Point(-3, 2, 1), Point(-1, -1, 0), Point(1, 0, 0), Point(0, 1, 0)),
-1)
# The following tests are based on pencil-and-paper drawings
# as well as hours spent debugging the DelaunayTriangulation.
self.assertEqual(incircle(
Point(1, 0, 0), Point(-0.6, 3.2, 1), Point(3.2, 2.1, 1),
Point(-2, 0, 1)),
-1)
self.assertEqual(incircle(
Point(-2, 0, 1),
Point(-0.6, 3.2, 1),
Point(0, 1, 0),
Point(1, 0, 0)),
-1)
def setUp(self):
"""Make some objects that are useful for most tests."""
self.a = Point(0, 0)
self.b = Point(1, 2)
self.c = Point(1, 2, 3)
def test_locally_delaunay(self):
"""Make sure that the locally delaunay test works."""
def quick_delaunay_test(*points, expectation=True):
"""Tests that the faces defined by points[:-1] and points[1:] share
an edge that is locally delaunay iff we expect it to be so.
"""
vertices = [DelT.Vertex(point) for point in points]
face_1 = DelT.Face(vertices[:-1])
face_2 = DelT.Face(vertices[1:])
facet_1 = face_1.half_facets[vertices[0]]
facet_2 = face_2.half_facets[vertices[-1]]
facet_1.twin = facet_2
facet_2.twin = facet_1
self.assertEqual(facet_1.lineside(facet_1.opposite.point), 1)
self.assertEqual(facet_1.lineside(facet_1.opposite.point), 1)
self.assertEqual(facet_1.locally_delaunay(), expectation)
self.assertEqual(facet_1.locally_delaunay(),
facet_2.locally_delaunay())
# Test for one dimension first.
quick_delaunay_test(Point(-1, 1),
Point(2, 1),
Point(3, 1),
expectation=True)
# points_1 = [Point(-1, 1), Point(2, 1), Point(3, 1)]
# vertices_1 = [DelT.Vertex(point) for point in points_1]
# half_facet_1 = DelT.HalfFacet(vertices_1[0], vertices_1[1:2],
# None)
# Basic cases in 2 dimensions
quick_delaunay_test(Point(0, 2, 1),
Point(-1, 0, 1),
Point(1, 0, 1),
Point(0, -1, 1),
expectation=True)
quick_delaunay_test(Point(0, 2, 1),
Point(-1, 0, 1),
Point(1, 0, 1),
Point(0, -0.3, 1),
expectation=False)
# Similar basic 3D cases
unit_circle_pts_3d = [
Point(0, 0, -1, 1),
Point(0, 1, 0, 1),
Point(0, -1, 0, 1),
Point(1, 0, 0, 1)
]
quick_delaunay_test(*unit_circle_pts_3d,
Point(0, 0, 1.5, 1),
expectation=True)
quick_delaunay_test(*unit_circle_pts_3d,
Point(0, 0, 0.5, 1),
expectation=False)
# Cases with infinite points in the plane:
quick_delaunay_test(Point(0, 1, 0),
Point(0.5, -400, 1),
Point(0, 0, 1),
Point(-1, -1, 0),
expectation=True)
quick_delaunay_test(Point(-2, 0, 1),
Point(-0.6, 3.2, 1),
Point(3.2, 2.1, 1),
Point(1, 0, 0),
expectation=True)
def test_length(self):
"""Test to see if length of a point makes sense"""
self.assertTrue(len(self.c) == 3)
self.assertTrue(len(Point(1, 2, 3, 4)) == 4)
self.assertFalse(len(self.b) == 3)
def test_subtraction(self):
"""Test point subtraction"""
self.assertIsInstance(self.b - self.a, Vector)
self.assertTrue(self.b - self.b == Vector(0, 0))
self.assertTrue(self.b - self.a == Vector(1, 2))
self.assertFalse(self.b - self.b == Point(0, 0))
def test_ccw_homogeneous(self):
"""Tests ccw with extended homogeneous coordinates"""
# One dimensional case:
# Basic, hair-not-on-fire requirement
self.assertNotEqual(ccw(Point(0, 1), Point(1, 1)), 0)
self.assertEqual(ccw(Point(0, 1), Point(1, 1)),
ccw(Point(0), Point(1), homogeneous=False))
# With one homogeneous coordinate
self.assertEqual(ccw(Point(0, 1), Point(1, 1)),
ccw(Point(-1, 0), Point(2, 1)))
# With two homogeneous coordinates
self.assertEqual(ccw(Point(0, 1), Point(1, 1)),
ccw(Point(-10, 0), Point(5, 0)))
# Make sure simple stuff works
# Should be counterclockwise:
self.assertEqual(ccw(self.homo_north, self.homo_south, self.homo_east),
1)
# Should be colinear:
self.assertEqual(ccw(Point(1, 0, 1), Point(0, 0, 1), Point(-1, 0, 1)),
0)
# Should be clockwise:
self.assertEqual(ccw(self.homo_north, self.homo_east, self.homo_south),
-1)
# Now try some weird stuff
# Tests involving one infinitely distance point:
self.assertEqual(ccw(Point(1, 0, 1), Point(0, 0, 1), Point(0, 1, 0)),
-1)
# Tests involving two infinitely distance points:
self.assertEqual(ccw(Point(1, 0, 0), Point(0, 0, 1), Point(0, 1, 0)),
-1)
self.assertEqual(ccw(Point(0, 1, 0), Point(0, 0, 1), Point(1, 0, 0)),
1)
# Test with three points on the "boundary of the plane"
self.assertEqual(ccw(Point(0, 1, 0), Point(-1, 0, 0), Point(0, -1, 0)),
1)
self.assertEqual(ccw(Point(0, 1, 0), Point(1, 0, 0), Point(0, -1, 0)),
-1)
# Same but with weirder points
self.assertEqual(ccw(Point(1.8, 19, 0),
Point(309.7, 1, 0),
Point(-0.05, -10, 0)),
-1)
# ANY finite point must satisfy this:
queries = [Point(0, 0, 1), Point(1232, 4, 1),
Point(-320, -0.0, 1), Point(-1, -1, 1),
Point(1, 0, 1), Point(0, 1, 1)]
for query in queries:
self.assertEqual(ccw(Point(0, 1, 0), Point(-1, -1, 0), query), 1)
self.assertEqual(ccw(Point(1, 0, 0), Point(0, 1, 0), query), 1)
class PointTestCase(unittest.TestCase):
"""Unit tests for the Point class."""
def setUp(self):
"""Make some objects that are useful for most tests."""
self.a = Point(0, 0)
self.b = Point(1, 2)
self.c = Point(1, 2, 3)
def test_point_equal(self):
"""Tests if comparison of points for equality works"""
self.assertTrue(Point(0, -9, 11.2) == Point(0, -9, 11.2))
self.assertFalse(Point(0, -9, 1600002) == Point(0, -8, 1600002))
# Different location
self.assertFalse(Point(1, 4) == Point(1, 4, 5))
# Drew's tests:
self.assertFalse(self.a == self.b)
self.assertTrue(self.b == self.b)
self.assertTrue(Point(1, 2, 3) == Point(1, 2, 3))
self.assertFalse(self.b == self.c)
self.assertFalse(self.b == (1, 2))
def test_misc_niceties(self):
"""I don't want the empty point to be a thing. You may disagree."""
with self.assertRaises(ValueError):
Point() # Try to make an empty point.
# Make sure that we can evaluate a point to True
self.assertTrue(self.a)
def test_lift(self):
"""Make sure lifting works nicely."""
# Define a function to use for testing
def f(x):
return x[0] * 2
self.assertTrue(self.b.lift(f) == Point(1, 2, 2))
self.assertFalse(self.c.lift(f) == Point(1, 2, 3, 4))
self.assertFalse(self.c.lift(f) == Point(1, 2, 3))
# Make sure that lifting a Point returns a Point
self.assertIsInstance(self.b.lift(f), Point)
def test_length(self):
"""Test to see if length of a point makes sense"""
self.assertTrue(len(self.c) == 3)
self.assertTrue(len(Point(1, 2, 3, 4)) == 4)
self.assertFalse(len(self.b) == 3)
def test_indexing(self):
"""Make sure that we can access elements of a point by index"""
self.assertTrue(self.a[0] == 0)
self.assertTrue(self.c[2] == 3)
self.assertFalse(self.b[-1] == 10)
with self.assertRaises(Exception):
# I want a warning when I accidentally try to set values:
self.b[-1] = 10
self.assertIsInstance(self.a[:-1], Point)
def test_subtraction(self):
"""Test point subtraction"""
self.assertIsInstance(self.b - self.a, Vector)
self.assertTrue(self.b - self.b == Vector(0, 0))
self.assertTrue(self.b - self.a == Vector(1, 2))
self.assertFalse(self.b - self.b == Point(0, 0))
def test_to_vector(self):
"""Test turning points into vectors"""
self.assertEqual(self.c.to_vector(), Vector(1, 2, 3))
self.assertEqual(self.a.to_vector(), Vector(0, 0))
self.assertEqual(self.b.to_vector(), Vector(1, 2))
self.assertNotEqual(self.b.to_vector(), Vector(1, 2, 0))
def test_hashing(self):
"""Make sure point hashing works and does not cause collisions"""
# Add 400 points' hashes to a set and make sure 400 things are in the
# set
some_hashes = set()
for x in range(-10, 10):
for y in range(-10, 10):
some_hashes.add(hash(Point(x, y, 1)))
self.assertEqual(len(some_hashes), 400)
self.assertEqual(hash(Point(0, 1, 2)),
hash(Point(0, 1, 2)))
