class HierarchyTest(unittest.TestCase):
def setUp(self):
self.initial_vecs = [[10], [30]]
self.h = Hierarchy(metric='euclidean',
lower_limit_scale=0.1,
upper_limit_scale=1.5)
self.h.fit(self.initial_vecs)
self.initial_leaves = [0,1]
self.initial_clus = 2
def _build_cluster_node(self, num_children=2):
"""
Just builds a cluster node with two leaf node children.
"""
children = [self.h.create_node(vec=[i*20]) for i in range(num_children)]
return self.h.create_node(children=children)
def test_init(self):
# The dist and graph matrices are square (nxn).
self.assertEqual(self.h.dists.shape, (3,3))
self.assertEqual(self.h.g.mx.shape, (3,3))
# The centers matrix is nxm.
self.assertEqual(self.h.centers.shape, (3,1))
def test_fit_returns_uuids(self):
vecs = [[20], [30], [40]]
new_uuids = self.h.fit(vecs)
self.assertEqual(new_uuids, [3,4,6])
def test_save_and_load(self):
save_path = '/tmp/hierarchy.ihac'
if os.path.exists(save_path):
os.remove(save_path)
points = generate_random_points()
self.h.fit(points)
ids = self.h.ids
graph = self.h.g.mx
dists = self.h.dists
ndists = self.h.ndists
centers = self.h.centers
avail = self.h.available_ids
self.h.save(save_path)
self.h.fit(points)
h = Hierarchy.load(save_path)
assert_array_equal(graph, h.g.mx)
assert_array_equal(dists, h.dists)
assert_array_equal(ids, h.ids)
assert_array_equal(ndists, h.ndists)
assert_array_equal(centers, h.centers)
assert_array_equal(avail, h.available_ids)
def test_create_node(self):
node = self.h.create_node(vec=[20])
expected_dists = np.array([[ 0., 20., 10., 10.],
[ 20., 0., 10., 10.],
[ 10., 10., 0., 0.],
[ 10., 10., 0., 0.]])
# Distance matrix should be reshaped.
self.assertEqual(self.h.dists.shape, (4,4))
self.assertTrue((self.h.dists == expected_dists).all())
self.assertEqual(self.h.nodes, self.initial_leaves + [self.initial_clus, node])
# Id should properly be assigned.
self.assertEqual(node, 3)
# Params should be passed through.
self.assertEqual(self.h.centers[node], [20])
def test_delete_node(self):
# Create a simple hierarchy to test.
nodes = [self.h.create_node(vec=[i*10]) for i in range(5)]
children = nodes[:3]
siblings = nodes[3:]
n = self.h.create_node(children=children)
parent = self.h.create_node(children=siblings + [n])
assert_array_equal(self.h.g.get_siblings(n), siblings)
assert_array_equal(self.h.g.get_parent(n), parent)
assert_array_equal(self.h.g.get_children(n), children)
old_ids = [n] + [c for c in self.h.g.get_children(n)]
self.h.delete_node(n)
# Node should be gone from the hierarchy.
assert_array_equal(self.h.g.get_siblings(n), [])
self.assertEqual(self.h.g.get_parent(n), None)
self.assertTrue(n not in self.h.g.get_children(parent))
for s in siblings:
self.assertTrue(n not in self.h.g.get_siblings(s))
# The node and its children's ids should be available for reuse.
self.assertEqual(set(self.h.available_ids), set(old_ids))
# Its children should also be deleted.
for c in children:
self.assertEqual(self.h.g.get_siblings(c), [])
self.assertEqual(self.h.g.get_parent(c), None)
# The ids should be reused.
new_nodes = [self.h.create_node(vec=[i*10]) for i in range(len(old_ids))]
for nn in new_nodes:
self.assertTrue(nn in old_ids)
def test_demote(self):
# If N_i and N_j are sibling nodes,
# DEMOTE(N_i, N_j)
# will set N_j as a child to N_i.
# Build three sibling cluster nodes.
n_i = self._build_cluster_node()
n_j = self._build_cluster_node()
n_k = self._build_cluster_node()
parent = self.h.create_node(children=[n_i, n_j, n_k])
self.h.demote(n_i, n_j)
self.assertEqual(n_i, self.h.g.get_parent(n_j))
def test_demote_omits_clusters_with_only_childs(self):
# If demoting causes a cluster node to have only one child, that node
# should be removed and replaced by its only child node.
# Build two sibling cluster nodes.
n_i = self._build_cluster_node()
n_j = self._build_cluster_node()
parent = self.h.create_node(children=[n_i, n_j])
self.h.demote(n_i, n_j)
# The parent should be removed.
self.assertFalse(parent in self.h.nodes)
# n_i should be the root now.
self.assertTrue(self.h.g.is_root(n_i))
self.assertTrue(n_j in self.h.g.get_children(n_i))
self.assertEqual(self.h.g.get_parent(n_j), n_i)
def test_merge(self):
# If N_i and N_j are sibling nodes under a parent N,
# MERGE(N_i, N_j)
# will create a new cluster node, N_k, with N_i and N_j
# as its chidlren and N as its parent.
parent = self._build_cluster_node(num_children=3)
n_i, n_j, n_p = self.h.g.get_children(parent)
# All three nodes are siblings.
self.assertEqual(self.h.g.get_siblings(n_p), [n_i, n_j])
self.h.merge(n_i, n_j)
# The old parent should be replaced.
n_k = self.h.g.get_parent(n_i)
self.assertNotEqual(n_k, parent)
# Now n_i and n_j should be in their own cluster.
self.assertEqual(self.h.g.get_siblings(n_i), [n_j])
# And that new cluster should be a sibling to the remaining node.
self.assertEqual(self.h.g.get_siblings(n_p), [n_k])
def test_split(self):
# If N_k is a cluster node with a set of children S_k,
# SPLIT(θ, N_k)
# will split N_k into two new nodes, N_i and N_j, each with a different
# subset of S_k (S_i and S_j, respectively). S_k is split by disconnecting an
# edge in N_k's minimum spanning tree (MST).
n_i = self.h.to_iid(self.h.incorporate([10.05]))
n_j = self.h.to_iid(self.h.incorporate([10.08]))
n_k = self.h.to_iid(self.h.incorporate([10.10]))
sibs = self.h.g.get_siblings(self.initial_leaves[0])
parent = self.h.g.get_parent(self.initial_leaves[0])
self.assertEqual(sibs, [n_i, n_j, n_k])
self.h.split(parent)
# n_i, n_j, and n_k are all closer to each other than they are to the initial leaf,
# so we expect them to be in their own cluster.
self.assertEqual(self.h.g.get_siblings(n_i), [n_j, n_k])
self.assertEqual(self.h.g.get_siblings(self.initial_leaves[0]), [self.initial_leaves[1], self.h.g.get_parent(n_i)])
def test_restructure(self):
# This isn't a comprehensive test, but a simple check.
# As the only two nodes initially, these two are siblings.
self.assertEqual(self.h.g.get_siblings(self.initial_leaves[0]), [self.initial_leaves[1]])
# Add some new nodes very close to the first leaf node ([10]).
n_i = self.h.to_iid(self.h.incorporate([10.05]))
n_j = self.h.to_iid(self.h.incorporate([10.08]))
n_k = self.h.to_iid(self.h.incorporate([10.10]))
# The second leaf node ([30]) should be different enough that it should
# have moved to its own cluster.
self.assertNotEqual(self.h.g.get_siblings(self.initial_leaves[0]), [self.initial_leaves[1]])
def test_ins_hierarchy(self):
# If N_i is a node in the hierarchy, child to node N,
# and N_j is a node not yet in the hierarchy,
# INS_HIERARCHY(N_i, N_j)
# creates a new node N_k with children N_i and N_j and N as its parent.
# Build a node with a parent and another node.
n_i = self.h.g.get_children(self._build_cluster_node())[0]
n_j = self.h.create_node(vec=[20])
self.h.ins_hierarchy(n_i, n_j)
# The nodes should be siblings now.
self.assertEqual(self.h.g.get_siblings(n_i), [n_j])
def test_incorporate_adds_to_existing_cluster_node(self):
# A node this close should be added as a sibling.
node_i = self.h.to_iid(self.h.incorporate([11]))
self.assertEqual(self.h.g.get_siblings(self.initial_leaves[0]), [node_i])
def test_incorporate_creates_new_cluster_node(self):
# The cluster node and the new node should be siblings.
node_i = self.h.to_iid(self.h.incorporate([90]))
self.assertEqual(self.h.g.get_siblings(self.initial_clus), [node_i])
def test_prune(self):
self.h.fit([[20], [30]])
self.assertEqual(self.h.available_ids, [])
assert_array_equal(self.h.g.leaves, [0,1,3,4])
self.h.prune([5])
self.assertEqual(self.h.available_ids, [1,4,5])
assert_array_equal(self.h.g.leaves, [0,3])
assert_array_equal(self.h.nodes, [0,2,3])
def test_clusters(self):
node_i = self.h.to_iid(self.h.incorporate([90]))
node_j = self.h.to_iid(self.h.incorporate([40]))
clusters = self.h.clusters(distance_threshold=14.0, with_labels=False)
self.assertEqual(clusters, [self.initial_leaves + [node_j], [node_i]])
clusters = self.h.clusters(distance_threshold=71.0, with_labels=False)
self.assertEqual(clusters, [self.initial_leaves + [node_j, node_i]])
clusters = self.h.clusters(distance_threshold=0.0, with_labels=False)
self.assertEqual(clusters, [[self.initial_leaves[0]], [self.initial_leaves[1]], [node_j], [node_i]])
class ClusterNodeTest(unittest.TestCase):
def setUp(self):
"""
Keep it simple: 5 1-dimensional datapoints::
[[1],
[2],
[4],
[8],
[12]]
The child distance matrix will look like::
[[ 0. 1. 3. 7. 11.]
[ 1. 0. 2. 6. 10.]
[ 3. 2. 0. 4. 8.]
[ 7. 6. 4. 0. 4.]
[ 11. 10. 8. 4. 0.]]
"""
self.data = np.array([[1],[2],[4],[8],[12]])
# Initialize the hierarchy with the first two datapoints.
self.h = Hierarchy()
self.h.fit(self.data[:2])
# Create (leaf) nodes for each other datapoint.
self.nodes = self.h.nodes[:2] + [self.h.create_node(vec=vec) for vec in self.data[2:]]
# Create the cluster node to test with.
self.c = self.h.create_node(children=self.nodes)
def test_init(self):
c = self.c
self.assertTrue(self.h.g.is_cluster(c))
# The center should be the mean of the datapoints.
expected_center = (1+2+4+8+12)/5
self.assertEquals(self.h.centers[c], expected_center)
# The mean of the nearest distances.
mins = [1,1,4,2,4]
expected_nearest_distance_mean = sum(mins)/len(mins)
self.assertAlmostEqual(np.mean(self.h.get_nearest_distances(c)), expected_nearest_distance_mean, places=6)
# The std of the nearest distances.
expected_nearest_distance_std = math.sqrt(sum([(min - expected_nearest_distance_mean)**2 for min in mins])/len(mins))
self.assertAlmostEqual(np.std(self.h.get_nearest_distances(c)), expected_nearest_distance_std, places=6)
def test_split_children(self):
"""
The MST for self.c looks like::
[[ 0. 1. 0. 0. 0.]
[ 0. 0. 2. 0. 0.]
[ 0. 0. 0. 4. 0.]
[ 0. 0. 0. 0. 4.]
[ 0. 0. 0. 0. 0.]]
Visually, the MST looks something like::
(0)--1--(1)--2--(2)--4--(3)--3--(4)
Where::
(A)--C--(B)
Means A and B are connected by an edge with weight C.
So splitting at the greatest edge, we get::
(0)--1--(1)--2--(2) (3)--3--(4)
"""
children = self.h.g.get_children(self.c).copy()
c_i, c_j = self.h.split(self.c)
expected_i_children = [children[i] for i in [0,1,2]]
expected_j_children = [children[i] for i in [3,4]]
assert_array_equal(self.h.g.get_children(c_i), expected_i_children)
assert_array_equal(self.h.g.get_children(c_j), expected_j_children)
class GraphTest(unittest.TestCase):
"""
Test the managing of the adjacency matrix.
"""
def setUp(self):
self.initial_vecs = [[10], [20]]
self.h = Hierarchy(metric='euclidean',
lower_limit_scale=0.1,
upper_limit_scale=1.5)
self.h.fit(self.initial_vecs)
self.g = self.h.g
self.extra_vecs = [[0], [20]]
children = [self.h.create_node(vec=vec) for vec in self.extra_vecs]
n = self.h.create_node(children=children)
self.g.add_child(2, n)
self.leaves = [0,1,3,4]
self.clusters = [2,5]
def test_is_cluster(self):
for clus in self.clusters:
self.assertTrue(self.g.is_cluster(clus))
for l in self.leaves:
self.assertFalse(self.g.is_cluster(l))
def test_is_root(self):
clus = self.clusters[0]
self.assertTrue(self.g.is_root(clus))
self.assertFalse(self.g.is_root(self.clusters[1]))
for l in self.leaves:
self.assertFalse(self.g.is_root(l))
self.assertEqual(clus, self.g.root)
# Try making a new root.
# If the existing root becomes a child, its parent
# is the new root.
new_root = self.h.create_node(children=[clus, 4])
self.assertTrue(self.g.is_root(new_root))
self.assertFalse(self.g.is_root(clus))
self.assertEqual(new_root, self.g.root)
def test_leaves(self):
assert_array_equal(self.g.leaves, [0,1,3,4])
def test_nodes(self):
assert_array_equal(self.h.nodes, [0,1,2,3,4,5])
def test_get_parent(self):
for n in [0,1,5]:
assert_array_equal(self.g.get_parent(n), 2)
for n in [3,4]:
assert_array_equal(self.g.get_parent(n), 5)
assert_array_equal(self.g.get_parent(2), None)
def test_get_children(self):
assert_array_equal(self.g.get_children(2), [0,1,5])
assert_array_equal(self.g.get_children(5), [3,4])
for l in self.leaves:
assert_array_equal(self.g.get_children(l), [])
def test_reset_node(self):
self.g.reset_node(2)
assert_array_equal(self.g.get_children(2), [])
def test_get_siblings(self):
assert_array_equal(self.g.get_siblings(0), [1,5])
assert_array_equal(self.g.get_siblings(1), [0,5])
assert_array_equal(self.g.get_siblings(5), [0,1])
assert_array_equal(self.g.get_siblings(2), [])
assert_array_equal(self.g.get_siblings(4), [3])
assert_array_equal(self.g.get_siblings(3), [4])
def test_get_leaves(self):
assert_array_equal(self.g.get_leaves(0), [0])
assert_array_equal(self.g.get_leaves(1), [1])
assert_array_equal(self.g.get_leaves(2), [0,1,3,4])
assert_array_equal(self.g.get_leaves(5), [3,4])
def test_add_child(self):
n = self.h.create_node(vec=[80])
self.g.add_child(2, n)
self.assertEqual(self.g.get_parent(n), 2)
self.assertTrue(n in self.g.get_children(2))
# Changing children should automatically remove it from its previous parent.
self.g.add_child(5, n)
self.assertNotEqual(self.g.get_parent(n), 2)
self.assertEqual(self.g.get_parent(n), 5)
self.assertFalse(n in self.g.get_children(2))
self.assertTrue(n in self.g.get_children(5))
def test_remove_child(self):
n = self.h.create_node(vec=[80])
self.g.add_child(2, n)
self.assertEqual(self.g.get_parent(n), 2)
self.assertTrue(n in self.g.get_children(2))
self.g.remove_child(2, n)
self.assertNotEqual(self.g.get_parent(n), 2)
self.assertFalse(n in self.g.get_children(2))
class DistancesTest(unittest.TestCase):
"""
Tests the management of distances (in the dists matrix).
"""
def setUp(self):
self.vecs = [[10], [20], [0], [20]]
self.initial_vecs = self.vecs[:2]
self.h = Hierarchy(metric='euclidean',
lower_limit_scale=0.1,
upper_limit_scale=1.5)
self.h.fit(self.initial_vecs)
children = [self.h.create_node(vec=vec) for vec in self.vecs[2:]]
n = self.h.create_node(children=children)
self.h.g.add_child(2, n)
self.leaves = [0,1,3,4]
self.clusters = [2,5]
def test_distance(self):
node_k = self.h.create_node(vec=[20])
# Distances should be symmetric.
for n in self.leaves:
d = self.h.get_distance(n, node_k)
d_ = self.h.get_distance(node_k, n)
self.assertEqual(d, d_)
def test_update_distances(self):
# Create some extra nodes.
data = np.array([[1],[2],[4],[8],[12]])
nodes = [self.h.create_node(vec=center) for center in data]
# Calculate a distance matrix independently to compare to.
# We include the vector which initialized the hierarchy
# and the center of the initial cluster node.
old_data = self.initial_vecs + [self.h.centers[self.clusters[0]]] + self.vecs[2:] + [self.h.centers[self.clusters[1]]]
data = np.insert(data, 0, old_data, axis=0)
dist_mat = pairwise_distances(data, metric='euclidean')
self.assertTrue((dist_mat == self.h.dists).all())
def test_cdm(self):
# Expecting the matrix to have rows and columns 0,1,n (n=5)
# since those are the child nodes.
expected = [[ 0., 10., 0.],
[10., 0., 10.],
[ 0., 10., 0.]]
assert_array_equal(expected, self.h.cdm(2))
def test_get_closest_leaf(self):
node_k = self.h.create_node(vec=[11])
result, dist = self.h.get_closest_leaf(node_k)
self.assertEqual(result, self.leaves[0])
self.assertEqual(dist, 1)
def test_get_nearest_distances(self):
d = self.h.get_nearest_distances(2)
expected = [ 0., 10., 0.]
assert_array_equal(expected, d)
def test_get_nearest_child(self):
"""
2
+-+--+
0 1 5
+-+
3 4
"""
i, d = self.h.get_nearest_child(5, 1)
self.assertEqual(i, 4)
self.assertEqual(d, 0)
def test_get_nearest_children(self):
i, j, d = self.h.get_nearest_children(2)
self.assertEqual(i, 0)
self.assertEqual(j, 5)
self.assertEqual(d, 0)
def test_get_furthest_nearest_children(self):
i, j, d = self.h.get_furthest_nearest_children(2)
self.assertEqual(i, 0)
self.assertEqual(j, 1)
self.assertEqual(d, 10)
def test_get_representative(self):
r = self.h.get_representative(2)
self.assertEqual(r, 0)
def test_most_representative(self):
# Incorporating these vectors puts the center of all nodes around ~22
new_vecs = [[30], [40], [40]]
self.h.fit(new_vecs)
nodes = self.h.nodes
rep = self.h.most_representative(nodes)
# Expecting that the representative node is 1, w/ a center of [20]
self.assertEqual(rep, 1)
class GraphTest(unittest.TestCase):
"""
Test the managing of the adjacency matrix.
"""
def setUp(self):
self.initial_vecs = [[10], [20]]
self.h = Hierarchy(metric='euclidean',
lower_limit_scale=0.1,
upper_limit_scale=1.5)
self.h.fit(self.initial_vecs)
self.g = self.h.g
self.extra_vecs = [[0], [20]]
children = [self.h.create_node(vec=vec) for vec in self.extra_vecs]
n = self.h.create_node(children=children)
self.g.add_child(2, n)
self.leaves = [0, 1, 3, 4]
self.clusters = [2, 5]
def test_is_cluster(self):
for clus in self.clusters:
self.assertTrue(self.g.is_cluster(clus))
for l in self.leaves:
self.assertFalse(self.g.is_cluster(l))
def test_is_root(self):
clus = self.clusters[0]
self.assertTrue(self.g.is_root(clus))
self.assertFalse(self.g.is_root(self.clusters[1]))
for l in self.leaves:
self.assertFalse(self.g.is_root(l))
self.assertEqual(clus, self.g.root)
# Try making a new root.
# If the existing root becomes a child, its parent
# is the new root.
new_root = self.h.create_node(children=[clus, 4])
self.assertTrue(self.g.is_root(new_root))
self.assertFalse(self.g.is_root(clus))
self.assertEqual(new_root, self.g.root)
def test_leaves(self):
assert_array_equal(self.g.leaves, [0, 1, 3, 4])
def test_nodes(self):
assert_array_equal(self.h.nodes, [0, 1, 2, 3, 4, 5])
def test_get_parent(self):
for n in [0, 1, 5]:
assert_array_equal(self.g.get_parent(n), 2)
for n in [3, 4]:
assert_array_equal(self.g.get_parent(n), 5)
assert_array_equal(self.g.get_parent(2), None)
def test_get_children(self):
assert_array_equal(self.g.get_children(2), [0, 1, 5])
assert_array_equal(self.g.get_children(5), [3, 4])
for l in self.leaves:
assert_array_equal(self.g.get_children(l), [])
def test_reset_node(self):
self.g.reset_node(2)
assert_array_equal(self.g.get_children(2), [])
def test_get_siblings(self):
assert_array_equal(self.g.get_siblings(0), [1, 5])
assert_array_equal(self.g.get_siblings(1), [0, 5])
assert_array_equal(self.g.get_siblings(5), [0, 1])
assert_array_equal(self.g.get_siblings(2), [])
assert_array_equal(self.g.get_siblings(4), [3])
assert_array_equal(self.g.get_siblings(3), [4])
def test_get_leaves(self):
assert_array_equal(self.g.get_leaves(0), [0])
assert_array_equal(self.g.get_leaves(1), [1])
assert_array_equal(self.g.get_leaves(2), [0, 1, 3, 4])
assert_array_equal(self.g.get_leaves(5), [3, 4])
def test_add_child(self):
n = self.h.create_node(vec=[80])
self.g.add_child(2, n)
self.assertEqual(self.g.get_parent(n), 2)
self.assertTrue(n in self.g.get_children(2))
# Changing children should automatically remove it from its previous parent.
self.g.add_child(5, n)
self.assertNotEqual(self.g.get_parent(n), 2)
self.assertEqual(self.g.get_parent(n), 5)
self.assertFalse(n in self.g.get_children(2))
self.assertTrue(n in self.g.get_children(5))
def test_remove_child(self):
n = self.h.create_node(vec=[80])
self.g.add_child(2, n)
self.assertEqual(self.g.get_parent(n), 2)
self.assertTrue(n in self.g.get_children(2))
self.g.remove_child(2, n)
self.assertNotEqual(self.g.get_parent(n), 2)
self.assertFalse(n in self.g.get_children(2))
class ClusterNodeTest(unittest.TestCase):
def setUp(self):
"""
Keep it simple: 5 1-dimensional datapoints::
[[1],
[2],
[4],
[8],
[12]]
The child distance matrix will look like::
[[ 0. 1. 3. 7. 11.]
[ 1. 0. 2. 6. 10.]
[ 3. 2. 0. 4. 8.]
[ 7. 6. 4. 0. 4.]
[ 11. 10. 8. 4. 0.]]
"""
self.data = np.array([[1], [2], [4], [8], [12]])
# Initialize the hierarchy with the first two datapoints.
self.h = Hierarchy()
self.h.fit(self.data[:2])
# Create (leaf) nodes for each other datapoint.
self.nodes = self.h.nodes[:2] + [
self.h.create_node(vec=vec) for vec in self.data[2:]
]
# Create the cluster node to test with.
self.c = self.h.create_node(children=self.nodes)
def test_init(self):
c = self.c
self.assertTrue(self.h.g.is_cluster(c))
# The center should be the mean of the datapoints.
expected_center = (1 + 2 + 4 + 8 + 12) / 5
self.assertEquals(self.h.centers[c], expected_center)
# The mean of the nearest distances.
mins = [1, 1, 4, 2, 4]
expected_nearest_distance_mean = sum(mins) / len(mins)
self.assertAlmostEqual(np.mean(self.h.get_nearest_distances(c)),
expected_nearest_distance_mean,
places=6)
# The std of the nearest distances.
expected_nearest_distance_std = math.sqrt(
sum([(min - expected_nearest_distance_mean)**2
for min in mins]) / len(mins))
self.assertAlmostEqual(np.std(self.h.get_nearest_distances(c)),
expected_nearest_distance_std,
places=6)
def test_split_children(self):
"""
The MST for self.c looks like::
[[ 0. 1. 0. 0. 0.]
[ 0. 0. 2. 0. 0.]
[ 0. 0. 0. 4. 0.]
[ 0. 0. 0. 0. 4.]
[ 0. 0. 0. 0. 0.]]
Visually, the MST looks something like::
(0)--1--(1)--2--(2)--4--(3)--3--(4)
Where::
(A)--C--(B)
Means A and B are connected by an edge with weight C.
So splitting at the greatest edge, we get::
(0)--1--(1)--2--(2) (3)--3--(4)
"""
children = self.h.g.get_children(self.c).copy()
c_i, c_j = self.h.split(self.c)
expected_i_children = [children[i] for i in [0, 1, 2]]
expected_j_children = [children[i] for i in [3, 4]]
assert_array_equal(self.h.g.get_children(c_i), expected_i_children)
assert_array_equal(self.h.g.get_children(c_j), expected_j_children)
class DistancesTest(unittest.TestCase):
"""
Tests the management of distances (in the dists matrix).
"""
def setUp(self):
self.vecs = [[10], [20], [0], [20]]
self.initial_vecs = self.vecs[:2]
self.h = Hierarchy(metric='euclidean',
lower_limit_scale=0.1,
upper_limit_scale=1.5)
self.h.fit(self.initial_vecs)
children = [self.h.create_node(vec=vec) for vec in self.vecs[2:]]
n = self.h.create_node(children=children)
self.h.g.add_child(2, n)
self.leaves = [0, 1, 3, 4]
self.clusters = [2, 5]
def test_distance(self):
node_k = self.h.create_node(vec=[20])
# Distances should be symmetric.
for n in self.leaves:
d = self.h.get_distance(n, node_k)
d_ = self.h.get_distance(node_k, n)
self.assertEqual(d, d_)
def test_update_distances(self):
# Create some extra nodes.
data = np.array([[1], [2], [4], [8], [12]])
nodes = [self.h.create_node(vec=center) for center in data]
# Calculate a distance matrix independently to compare to.
# We include the vector which initialized the hierarchy
# and the center of the initial cluster node.
old_data = self.initial_vecs + [
self.h.centers[self.clusters[0]]
] + self.vecs[2:] + [self.h.centers[self.clusters[1]]]
data = np.insert(data, 0, old_data, axis=0)
dist_mat = pairwise_distances(data, metric='euclidean')
self.assertTrue((dist_mat == self.h.dists).all())
def test_cdm(self):
# Expecting the matrix to have rows and columns 0,1,n (n=5)
# since those are the child nodes.
expected = [[0., 10., 0.], [10., 0., 10.], [0., 10., 0.]]
assert_array_equal(expected, self.h.cdm(2))
def test_get_closest_leaf(self):
node_k = self.h.create_node(vec=[11])
result, dist = self.h.get_closest_leaf(node_k)
self.assertEqual(result, self.leaves[0])
self.assertEqual(dist, 1)
def test_get_nearest_distances(self):
d = self.h.get_nearest_distances(2)
expected = [0., 10., 0.]
assert_array_equal(expected, d)
def test_get_nearest_child(self):
"""
2
+-+--+
0 1 5
+-+
3 4
"""
i, d = self.h.get_nearest_child(5, 1)
self.assertEqual(i, 4)
self.assertEqual(d, 0)
def test_get_nearest_children(self):
i, j, d = self.h.get_nearest_children(2)
self.assertEqual(i, 0)
self.assertEqual(j, 5)
self.assertEqual(d, 0)
def test_get_furthest_nearest_children(self):
i, j, d = self.h.get_furthest_nearest_children(2)
self.assertEqual(i, 0)
self.assertEqual(j, 1)
self.assertEqual(d, 10)
def test_get_representative(self):
r = self.h.get_representative(2)
self.assertEqual(r, 0)
def test_most_representative(self):
# Incorporating these vectors puts the center of all nodes around ~22
new_vecs = [[30], [40], [40]]
self.h.fit(new_vecs)
nodes = self.h.nodes
rep = self.h.most_representative(nodes)
# Expecting that the representative node is 1, w/ a center of [20]
self.assertEqual(rep, 1)
class HierarchyTest(unittest.TestCase):
def setUp(self):
self.initial_vecs = [[10], [30]]
self.h = Hierarchy(metric='euclidean',
lower_limit_scale=0.1,
upper_limit_scale=1.5)
self.h.fit(self.initial_vecs)
self.initial_leaves = [0, 1]
self.initial_clus = 2
def _build_cluster_node(self, num_children=2):
"""
Just builds a cluster node with two leaf node children.
"""
children = [
self.h.create_node(vec=[i * 20]) for i in range(num_children)
]
return self.h.create_node(children=children)
def test_init(self):
# The dist and graph matrices are square (nxn).
self.assertEqual(self.h.dists.shape, (3, 3))
self.assertEqual(self.h.g.mx.shape, (3, 3))
# The centers matrix is nxm.
self.assertEqual(self.h.centers.shape, (3, 1))
def test_fit_returns_uuids(self):
vecs = [[20], [30], [40]]
new_uuids = self.h.fit(vecs)
self.assertEqual(new_uuids, [3, 4, 6])
def test_save_and_load(self):
save_path = '/tmp/hierarchy.ihac'
if os.path.exists(save_path):
os.remove(save_path)
points = generate_random_points()
self.h.fit(points)
ids = self.h.ids
graph = self.h.g.mx
dists = self.h.dists
ndists = self.h.ndists
centers = self.h.centers
avail = self.h.available_ids
self.h.save(save_path)
self.h.fit(points)
h = Hierarchy.load(save_path)
assert_array_equal(graph, h.g.mx)
assert_array_equal(dists, h.dists)
assert_array_equal(ids, h.ids)
assert_array_equal(ndists, h.ndists)
assert_array_equal(centers, h.centers)
assert_array_equal(avail, h.available_ids)
def test_create_node(self):
node = self.h.create_node(vec=[20])
expected_dists = np.array([[0., 20., 10., 10.], [20., 0., 10., 10.],
[10., 10., 0., 0.], [10., 10., 0., 0.]])
# Distance matrix should be reshaped.
self.assertEqual(self.h.dists.shape, (4, 4))
self.assertTrue((self.h.dists == expected_dists).all())
self.assertEqual(self.h.nodes,
self.initial_leaves + [self.initial_clus, node])
# Id should properly be assigned.
self.assertEqual(node, 3)
# Params should be passed through.
self.assertEqual(self.h.centers[node], [20])
def test_delete_node(self):
# Create a simple hierarchy to test.
nodes = [self.h.create_node(vec=[i * 10]) for i in range(5)]
children = nodes[:3]
siblings = nodes[3:]
n = self.h.create_node(children=children)
parent = self.h.create_node(children=siblings + [n])
assert_array_equal(self.h.g.get_siblings(n), siblings)
assert_array_equal(self.h.g.get_parent(n), parent)
assert_array_equal(self.h.g.get_children(n), children)
old_ids = [n] + [c for c in self.h.g.get_children(n)]
self.h.delete_node(n)
# Node should be gone from the hierarchy.
assert_array_equal(self.h.g.get_siblings(n), [])
self.assertEqual(self.h.g.get_parent(n), None)
self.assertTrue(n not in self.h.g.get_children(parent))
for s in siblings:
self.assertTrue(n not in self.h.g.get_siblings(s))
# The node and its children's ids should be available for reuse.
self.assertEqual(set(self.h.available_ids), set(old_ids))
# Its children should also be deleted.
for c in children:
self.assertEqual(self.h.g.get_siblings(c), [])
self.assertEqual(self.h.g.get_parent(c), None)
# The ids should be reused.
new_nodes = [
self.h.create_node(vec=[i * 10]) for i in range(len(old_ids))
]
for nn in new_nodes:
self.assertTrue(nn in old_ids)
def test_demote(self):
# If N_i and N_j are sibling nodes,
# DEMOTE(N_i, N_j)
# will set N_j as a child to N_i.
# Build three sibling cluster nodes.
n_i = self._build_cluster_node()
n_j = self._build_cluster_node()
n_k = self._build_cluster_node()
parent = self.h.create_node(children=[n_i, n_j, n_k])
self.h.demote(n_i, n_j)
self.assertEqual(n_i, self.h.g.get_parent(n_j))
def test_demote_omits_clusters_with_only_childs(self):
# If demoting causes a cluster node to have only one child, that node
# should be removed and replaced by its only child node.
# Build two sibling cluster nodes.
n_i = self._build_cluster_node()
n_j = self._build_cluster_node()
parent = self.h.create_node(children=[n_i, n_j])
self.h.demote(n_i, n_j)
# The parent should be removed.
self.assertFalse(parent in self.h.nodes)
# n_i should be the root now.
self.assertTrue(self.h.g.is_root(n_i))
self.assertTrue(n_j in self.h.g.get_children(n_i))
self.assertEqual(self.h.g.get_parent(n_j), n_i)
def test_merge(self):
# If N_i and N_j are sibling nodes under a parent N,
# MERGE(N_i, N_j)
# will create a new cluster node, N_k, with N_i and N_j
# as its chidlren and N as its parent.
parent = self._build_cluster_node(num_children=3)
n_i, n_j, n_p = self.h.g.get_children(parent)
# All three nodes are siblings.
self.assertEqual(self.h.g.get_siblings(n_p), [n_i, n_j])
self.h.merge(n_i, n_j)
# The old parent should be replaced.
n_k = self.h.g.get_parent(n_i)
self.assertNotEqual(n_k, parent)
# Now n_i and n_j should be in their own cluster.
self.assertEqual(self.h.g.get_siblings(n_i), [n_j])
# And that new cluster should be a sibling to the remaining node.
self.assertEqual(self.h.g.get_siblings(n_p), [n_k])
def test_split(self):
# If N_k is a cluster node with a set of children S_k,
# SPLIT(θ, N_k)
# will split N_k into two new nodes, N_i and N_j, each with a different
# subset of S_k (S_i and S_j, respectively). S_k is split by disconnecting an
# edge in N_k's minimum spanning tree (MST).
n_i = self.h.to_iid(self.h.incorporate([10.05]))
n_j = self.h.to_iid(self.h.incorporate([10.08]))
n_k = self.h.to_iid(self.h.incorporate([10.10]))
sibs = self.h.g.get_siblings(self.initial_leaves[0])
parent = self.h.g.get_parent(self.initial_leaves[0])
self.assertEqual(sibs, [n_i, n_j, n_k])
self.h.split(parent)
# n_i, n_j, and n_k are all closer to each other than they are to the initial leaf,
# so we expect them to be in their own cluster.
self.assertEqual(self.h.g.get_siblings(n_i), [n_j, n_k])
self.assertEqual(self.h.g.get_siblings(self.initial_leaves[0]),
[self.initial_leaves[1],
self.h.g.get_parent(n_i)])
def test_restructure(self):
# This isn't a comprehensive test, but a simple check.
# As the only two nodes initially, these two are siblings.
self.assertEqual(self.h.g.get_siblings(self.initial_leaves[0]),
[self.initial_leaves[1]])
# Add some new nodes very close to the first leaf node ([10]).
n_i = self.h.to_iid(self.h.incorporate([10.05]))
n_j = self.h.to_iid(self.h.incorporate([10.08]))
n_k = self.h.to_iid(self.h.incorporate([10.10]))
# The second leaf node ([30]) should be different enough that it should
# have moved to its own cluster.
self.assertNotEqual(self.h.g.get_siblings(self.initial_leaves[0]),
[self.initial_leaves[1]])
def test_ins_hierarchy(self):
# If N_i is a node in the hierarchy, child to node N,
# and N_j is a node not yet in the hierarchy,
# INS_HIERARCHY(N_i, N_j)
# creates a new node N_k with children N_i and N_j and N as its parent.
# Build a node with a parent and another node.
n_i = self.h.g.get_children(self._build_cluster_node())[0]
n_j = self.h.create_node(vec=[20])
self.h.ins_hierarchy(n_i, n_j)
# The nodes should be siblings now.
self.assertEqual(self.h.g.get_siblings(n_i), [n_j])
def test_incorporate_adds_to_existing_cluster_node(self):
# A node this close should be added as a sibling.
node_i = self.h.to_iid(self.h.incorporate([11]))
self.assertEqual(self.h.g.get_siblings(self.initial_leaves[0]),
[node_i])
def test_incorporate_creates_new_cluster_node(self):
# The cluster node and the new node should be siblings.
node_i = self.h.to_iid(self.h.incorporate([90]))
self.assertEqual(self.h.g.get_siblings(self.initial_clus), [node_i])
def test_prune(self):
self.h.fit([[20], [30]])
self.assertEqual(self.h.available_ids, [])
assert_array_equal(self.h.g.leaves, [0, 1, 3, 4])
self.h.prune([5])
self.assertEqual(self.h.available_ids, [1, 4, 5])
assert_array_equal(self.h.g.leaves, [0, 3])
assert_array_equal(self.h.nodes, [0, 2, 3])
def test_clusters(self):
node_i = self.h.to_iid(self.h.incorporate([90]))
node_j = self.h.to_iid(self.h.incorporate([40]))
clusters = self.h.clusters(distance_threshold=14.0, with_labels=False)
self.assertEqual(clusters, [self.initial_leaves + [node_j], [node_i]])
clusters = self.h.clusters(distance_threshold=71.0, with_labels=False)
self.assertEqual(clusters, [self.initial_leaves + [node_j, node_i]])
clusters = self.h.clusters(distance_threshold=0.0, with_labels=False)
self.assertEqual(clusters,
[[self.initial_leaves[0]], [self.initial_leaves[1]],
[node_j], [node_i]])
