def test_given_a_line_with_dupicate_points_return_a_point(self):
"""
Given a line with duplicate points, the alphashape function should
return a point
"""
alphashape([(0., 1.), (0., 1.)], 0)
assert shapely.geometry.Point([0., 1.]) == alphashape(
[(0., 1.), (0., 1.)], 0)
def test_given_a_line_with_unique_points_return_a_line(self):
"""
Given a line with unique points, the alphashape function should return
the same line
"""
assert shapely.geometry.LineString([(0., 0.), (0., 1.)]) == alphashape(
[(0., 0.), (0., 1.)], 0)
assert shapely.geometry.LineString([(1., 0.), (0., 1.)]) == alphashape(
[(1., 0.), (0., 1.)], 0)
def test_given_a_four_point_polygon_with_no_alpha_return_input(self):
"""
Given a polygon with four points, return the input as a polygon.
"""
assert shapely.geometry.Polygon([
(0., 0.), (0., 1.), (1., 1.), (1., 0.), (0., 0.)]).equals(
alphashape([(0., 0.), (0., 1.), (1., 1.), (1., 0.)]))
def test_given_a_triangle_with_two_duplicate_points_returns_a_line(self):
"""
Given a line with two unique points, the alphashape function should
return a line with the unique points
"""
assert shapely.geometry.LineString([(1., 0.), (0., 1.)]) == alphashape(
[(1., 0.), (0., 1.), (0., 1.)], 0)
def test_given_a_triangle_with_duplicate_points_returns_a_point(self):
"""
Given a triangle with two unique points, the alphashape function should
return a point
"""
assert shapely.geometry.Point((0., 1.)) == alphashape(
[(0., 1.), (0., 1.), (0., 1.)], 0)
def test_given_a_four_point_polygon_with_small_alpha_return_input(self):
"""
Given a polygon with four points, and an alpha value of zero, return
the input as a polygon.
"""
assert shapely.geometry.Polygon([
(0., 0.), (0., 1.), (1., 1.), (1., 0.), (0., 0.)]).equals(
alphashape([(0., 0.), (0., 1.), (1., 1.), (1., 0.)], 1.e-9))
def test_4_dimensional_regression(self):
"""
Given a 4-dimensional data set, return an expected set of edges.
"""
points_4d = [
(0., 0., 0., 0.), (0., 0., 0., 1.), (0., 0., 1., 0.),
(0., 1., 0., 0.), (0., 1., 1., 0.), (0., 1., 0., 1.),
(0., 0., 1., 1.), (0., 1., 1., 1.), (1., 0., 0., 0.),
(1., 0., 0., 1.), (1., 0., 1., 0.), (1., 1., 0., 0.),
(1., 1., 1., 0.), (1., 1., 0., 1.), (1., 0., 1., 1.),
(1., 1., 1., 1.), (.25, .5, .5, .5), (.5, .25, .5, .5),
(.5, .5, .25, .5), (.5, .5, .5, .25), (.75, .5, .5, .5),
(.5, .75, .5, .5), (.5, .5, .75, .5), (.5, .5, .5, .75)
]
expected = {
(16, 1, 2, 0), (16, 1, 3, 0), (16, 2, 3, 0),
(16, 4, 2, 3), (16, 4, 7, 2), (16, 4, 7, 3),
(16, 5, 1, 3), (16, 5, 7, 1), (16, 5, 7, 3),
(16, 6, 1, 2), (16, 6, 7, 1), (16, 6, 7, 2),
(17, 1, 2, 0), (17, 1, 8, 0), (17, 2, 8, 0),
(17, 6, 1, 2), (17, 6, 14, 1), (17, 6, 14, 2),
(17, 9, 1, 8), (17, 9, 14, 1), (17, 9, 14, 8),
(17, 10, 2, 8), (17, 10, 14, 2), (17, 10, 14, 8),
(18, 1, 3, 0), (18, 1, 8, 0), (18, 3, 8, 0),
(18, 5, 1, 3), (18, 5, 13, 1), (18, 5, 13, 3),
(18, 9, 1, 8), (18, 9, 13, 1), (18, 9, 13, 8),
(18, 11, 3, 8), (18, 11, 13, 3), (18, 11, 13, 8),
(19, 2, 3, 0), (19, 2, 8, 0), (19, 3, 8, 0),
(19, 4, 2, 3), (19, 4, 12, 2), (19, 4, 12, 3),
(19, 10, 2, 8), (19, 10, 12, 2), (19, 10, 12, 8),
(19, 11, 3, 8), (19, 11, 12, 3), (19, 11, 12, 8),
(20, 9, 13, 8), (20, 9, 14, 8), (20, 9, 14, 13),
(20, 10, 12, 8), (20, 10, 14, 8), (20, 10, 14, 12),
(20, 11, 12, 8), (20, 11, 13, 8), (20, 11, 13, 12),
(20, 13, 12, 15), (20, 14, 12, 15), (20, 14, 13, 15),
(21, 4, 7, 3), (21, 4, 7, 12), (21, 4, 12, 3),
(21, 5, 7, 3), (21, 5, 7, 13), (21, 5, 13, 3),
(21, 7, 12, 15), (21, 7, 13, 15), (21, 11, 12, 3),
(21, 11, 13, 3), (21, 11, 13, 12), (21, 13, 12, 15),
(22, 4, 7, 2), (22, 4, 7, 12), (22, 4, 12, 2),
(22, 6, 7, 2), (22, 6, 7, 14), (22, 6, 14, 2),
(22, 7, 12, 15), (22, 7, 14, 15), (22, 10, 12, 2),
(22, 10, 14, 2), (22, 10, 14, 12), (22, 14, 12, 15),
(23, 5, 7, 1), (23, 5, 7, 13), (23, 5, 13, 1),
(23, 6, 7, 1), (23, 6, 7, 14), (23, 6, 14, 1),
(23, 7, 13, 15), (23, 7, 14, 15), (23, 9, 13, 1),
(23, 9, 14, 1), (23, 9, 14, 13), (23, 14, 13, 15)}
results = alphashape(points_4d, 1.0)
self.assertTrue(len(results) == len(expected))
for edge in list(results):
self.assertTrue(any([e in expected for e in itertools.combinations(
edge, r=len(edge))]))
def test_given_a_point_return_a_point(self):
"""
Given a point, the alphashape function should return the same point
"""
assert shapely.geometry.Point([0., 0.]) == alphashape([(0., 0.)], 0)
assert shapely.geometry.Point([1., 0.]) == alphashape([(1., 0.)], 0)
assert shapely.geometry.Point([0., 1.]) == alphashape([(0., 1.)], 0)
assert shapely.geometry.Point([0., 0.]) == alphashape([(0., 0.)], 99)
assert shapely.geometry.Point([1., 0.]) == alphashape([(1., 0.)], 99)
assert shapely.geometry.Point([0., 1.]) == alphashape([(0., 1.)], 99)
def test_3_dimensional_regression_with_dynamic_alpha(self):
"""
Given a 3-dimensional data set, return an expected set of edges.
"""
points_3d = [
(0., 0., 0.), (0., 0., 1.), (0., 1., 0.),
(1., 0., 0.), (1., 1., 0.), (1., 0., 1.),
(0., 1., 1.), (1., 1., 1.), (.25, .5, .5),
(.5, .25, .5), (.5, .5, .25), (.75, .5, .5),
(.5, .75, .5), (.5, .5, .75)
]
expected = {
}
expected_vertices = [
[0., 0., 0.], [0., 0., 1.], [0., 1., 0.],
[0., 1., 1.], [1., 0., 0.], [1., 0., 1.],
[1., 1., 0.], [1., 1., 1.], [0.25, 0.5, 0.5],
[0.5, 0.25, 0.5], [0.5, 0.5, 0.25], [0.5, 0.5, 0.75],
[0.5, 0.75, 0.5], [0.75, 0.5, 0.5]]
expected_faces = [
(13, 10, 6), (13, 9, 4), (6, 12, 13),
(13, 12, 7), (5, 11, 9), (8, 10, 0),
(3, 12, 8), (0, 10, 9), (5, 9, 13),
(12, 11, 7), (9, 10, 4), (8, 9, 1),
(12, 10, 2), (13, 11, 5), (1, 11, 8),
(4, 10, 13), (9, 11, 1), (2, 10, 8),
(8, 12, 2), (3, 11, 12), (0, 9, 8),
(7, 11, 13), (6, 10, 12), (8, 11, 3)]
results = alphashape(points_3d, lambda a, b: 2.1)
self.assertTrue(len(results.vertices) == len(expected_vertices))
self.assertTrue(len(points_3d) == len(expected_vertices))
self.assertTrue(len(results.faces) == len(expected_faces))
vertex_map = {i: expected_vertices.index(
list(vertex)) for i,vertex in enumerate(results.vertices)}
for edge in list(results.faces):
self.assertTrue(any([(
vertex_map[e[0]],
vertex_map[e[1]],
vertex_map[e[2]]) in expected_faces \
for e in itertools.combinations(edge, r=len(edge))]))
