def test_sparse_equal_dense_if_variable_hits_per_row(shuffle_equal):
X, _ = make_classification(random_state=123)
dist = euclidean_distances(X)
dist[0, 1:3] = 999
dist[1:3, 0] = 999
dist[1, 1:5] = 999
dist[1:5, 1] = 999
sparse = dist.copy()
sparse[0, 1:3] = 0
sparse[1:3, 0] = 0
sparse[1, 1:5] = 0
sparse[1:5, 1] = 0
sparse = csr_matrix(sparse)
hub = Hubness(metric='precomputed',
shuffle_equal=shuffle_equal,
random_state=123)
hub.fit(dist)
skew_dense = hub.score(has_self_distances=True)
hub = Hubness(metric='precomputed',
shuffle_equal=shuffle_equal,
random_state=123)
hub.fit(sparse)
skew_sparse = hub.score(has_self_distances=True)
np.testing.assert_almost_equal(skew_dense, skew_sparse, decimal=2)
def test_parallel_hubness_equal_serial_hubness_distance_based(dist, n_jobs):
# Parallel
hub = Hubness(k=4,
metric='precomputed',
store_k_occurrence=True,
store_k_neighbors=True,
n_jobs=n_jobs)
hub.fit(dist)
skew_p = hub.score(has_self_distances=True)
neigh_p = hub.k_neighbors
occ_p = hub.k_occurrence
# Sequential
hub = Hubness(k=4,
metric='precomputed',
store_k_occurrence=True,
store_k_neighbors=True,
n_jobs=1)
hub.fit(dist)
skew_s = hub.score(has_self_distances=True)
neigh_s = hub.k_neighbors
occ_s = hub.k_occurrence
np.testing.assert_array_almost_equal(skew_p, skew_s, decimal=7)
np.testing.assert_array_almost_equal(neigh_p, neigh_s, decimal=7)
np.testing.assert_array_almost_equal(occ_p, occ_s, decimal=7)
def test_hubness_against_distance(has_self_distances):
"""Test hubness class against distance-based methods."""
np.random.seed(123)
X = np.random.rand(100, 50)
D = euclidean_distances(X)
verbose = 1
hub = Hubness(k=10, metric='precomputed',
store_k_occurrence=True,
store_k_neighbors=True,
)
hub.fit(D)
skew_d = hub.score(has_self_distances=has_self_distances)
neigh_d = hub.k_neighbors
occ_d = hub.k_occurrence
hub = Hubness(k=10, metric='euclidean',
store_k_neighbors=True,
store_k_occurrence=True,
verbose=verbose)
hub.fit(X)
skew_v = hub.score(X if not has_self_distances else None)
neigh_v = hub.k_neighbors
occ_v = hub.k_occurrence
np.testing.assert_allclose(skew_d, skew_v, atol=1e-7)
np.testing.assert_array_equal(neigh_d, neigh_v)
np.testing.assert_array_equal(occ_d, occ_v)
def test_handle_negative_neighbor_indices():
def mock_kneighbors(X_test):
nn = np.zeros((len(X_test), 2), dtype=int)
nn[:, 1] = -1
return nn
X, _ = make_classification(n_samples=10)
hub = Hubness()
hub.fit(X[:8, :])
hub._k_neighbors = mock_kneighbors
hub.score(X[8:, :])
def test_sparse_equal_dense(verbose, shuffle_equal):
X, _ = make_classification()
dist_dense = euclidean_distances(X)
dist_sparse = csr_matrix(dist_dense)
hub = Hubness(metric='precomputed',
shuffle_equal=shuffle_equal,
verbose=verbose)
hub.fit(dist_dense)
skew_dense = hub.score(has_self_distances=True)
hub.fit(dist_sparse)
skew_sparse = hub.score(has_self_distances=True)
np.testing.assert_almost_equal(skew_dense, skew_sparse)
def test_hubness(verbose):
"""Test hubness against ground truth calc on spreadsheet"""
HUBNESS_TRUE = -0.2561204163 # Hubness truth: S_k=5, skewness calculated with bias
hub = Hubness(k=2, metric='precomputed', verbose=verbose)
hub.fit(DIST)
Sk2 = hub.score(has_self_distances=True)
np.testing.assert_almost_equal(Sk2, HUBNESS_TRUE, decimal=10)
def test_hubness_return_values_are_self_consistent(n_samples, n_features, k,
seed):
"""Test that the three returned values fit together"""
np.random.seed(seed)
vectors = 99. * (np.random.rand(n_samples, n_features) - 0.5)
k = 10
hub = Hubness(k=k,
metric='euclidean',
store_k_neighbors=True,
store_k_occurrence=True)
hub.fit(vectors)
skew = hub.score()
neigh = hub.k_neighbors
occ = hub.k_occurrence
# Neighbors are just checked for correct shape
assert neigh.shape == (n_samples, k)
# Count k-occurrence (different method than in module)
neigh = neigh.ravel()
occ_true = np.zeros(n_samples, dtype=int)
for i in range(n_samples):
occ_true[i] = (neigh == i).sum()
np.testing.assert_array_equal(occ, occ_true)
# Calculate skewness (different method than in module)
x0 = occ - occ.mean()
s2 = (x0**2).mean()
m3 = (x0**3).mean()
skew_true = m3 / (s2**1.5)
np.testing.assert_equal(skew, skew_true)
def test_return_k_neighbors(store_k_neighbors):
X, _ = make_classification()
hub = Hubness(return_value='k_neighbors', store_k_neighbors=store_k_neighbors)
if store_k_neighbors:
hub.fit(X)
else:
with pytest.warns(UserWarning):
hub.fit(X)
_ = hub.score()
def test_atkinson():
X, _ = make_classification(random_state=123)
hub = Hubness(return_value='k_occurrence').fit(X)
k_occ = hub.score()
atkinson_0999 = hub._calc_atkinson_index(k_occ, eps=.999)
atkinson_1000 = hub._calc_atkinson_index(k_occ, eps=1)
np.testing.assert_almost_equal(atkinson_0999, atkinson_1000, decimal=3)
def test_return_k_occurrence(store_k_occurrence):
X, _ = make_classification()
hub = Hubness(return_value='k_occurrence', store_k_occurrence=store_k_occurrence)
if store_k_occurrence:
hub.fit(X)
else:
with pytest.warns(UserWarning):
hub.fit(X)
_ = hub.score()
def test_all_params_none():
X, _ = make_classification()
hub = Hubness(k=None, return_value=None, hub_size=None, metric=None,
store_k_neighbors=None, store_k_occurrence=None,
algorithm_params=None,
hubness=None, hubness_params=None,
verbose=None, n_jobs=None, random_state=None,
shuffle_equal=None)
hub.fit(X)
_ = hub.score()
def test_limiting_factor():
""" Different implementations of Gini index calculation should give the same result. """
X, _ = make_classification()
hub = Hubness(store_k_occurrence=True, return_value='k_occurrence')
hub.fit(X)
k_occ = hub.score()
gini_space = hub._calc_gini_index(k_occ, limiting='space')
gini_time = hub._calc_gini_index(k_occ, limiting='time')
gini_naive = hub._calc_gini_index(k_occ, limiting=None)
assert gini_space == gini_time == gini_naive
def test_all_but_gini():
X, _ = make_classification()
hub = Hubness(store_k_occurrence=True, return_value='all_but_gini',
store_k_neighbors=True)
hub.fit(X)
measures = hub.score()
for m in VALID_HUBNESS_MEASURES:
if m in ['all', 'all_but_gini']:
continue
elif m == 'gini':
assert m not in measures
else:
assert m in measures
def test_hubness_independent_on_data_set_size(hubness_measure):
""" New measures should pass, traditional skewness should fail. """
thousands = 3
n_objects = thousands * 1_000
rng = np.random.RandomState(1247)
X = rng.rand(n_objects, 128)
N_SAMPLES_LIST = np.arange(1, thousands + 1) * 1_000
value = np.empty(N_SAMPLES_LIST.size)
for i, n_samples in enumerate(N_SAMPLES_LIST):
ind = rng.permutation(n_objects)[:n_samples]
X_sample = X[ind, :]
hub = Hubness(return_value='all')
hub.fit(X_sample)
measures = hub.score()
if hubness_measure == 'k_skewness':
value[i] = hub.k_skewness
elif hubness_measure == 'k_skewness_truncnorm':
value[i] = hub.k_skewness_truncnorm
elif hubness_measure == 'robinhood':
value[i] = hub.robinhood_index
elif hubness_measure == 'gini':
value[i] = hub.gini_index
elif hubness_measure == 'atkinson':
value[i] = hub.atkinson_index
assert value[i] == measures[hubness_measure]
if i > 0:
if hubness_measure == 'k_skewness':
with np.testing.assert_raises(AssertionError):
np.testing.assert_allclose(value[i],
value[i - 1],
rtol=0.1)
else:
np.testing.assert_allclose(
value[i],
value[i - 1],
rtol=2e-1,
err_msg=(f'Hubness measure is too dependent on data set '
f'size with S({N_SAMPLES_LIST[i]}) = x '
f'and S({N_SAMPLES_LIST[i-1]}) = y.'))
if hubness_measure == 'k_skewness':
with np.testing.assert_raises(AssertionError):
np.testing.assert_allclose(value[-1], value[0], rtol=0.1)
else:
np.testing.assert_allclose(value[-1], value[0], rtol=2e-1)
def hub_eval(
input_points,
methods={
'nothing': (None, None),
'mp_normal': ('mp', {
'method': 'normal'
}),
'ls': ('ls', None),
'ls_nicdm': ('ls', {
'method': 'nicdm'
}),
'dsl': ('dsl', None)
},
k=k):
skewness = []
for method_name, (hubness, hubness_params) in tqdm(methods.items()):
hub = Hubness(k=k, hubness=hubness, hubness_params=hubness_params)
hub.fit(input_points)
skewness.append(hub.score())
return skewness
def measure_hubness(n_tracks, output_file, metric, projection, dimensions, n_jobs, random):
from skhubness import Hubness
tracks = Track.get_all(limit=n_tracks, random=random)
models = get_models()
models_iter = models.get_combinations() if projection is None else models.get_offline_projections(projection)
results = []
for model in list(models_iter):
for _dimensions in tqdm(range(2, dimensions+1), desc=str(model)):
embeddings = model.get_embeddings(tracks, dimensions=slice(_dimensions))
embeddings_stacked = np.vstack(embeddings)
hub = Hubness(k=10, metric=metric, return_value='all', n_jobs=n_jobs)
hub.fit(embeddings_stacked[:, :_dimensions])
result = {key: value for key, value in hub.score().items() if key in RETURN_VALUES}
result.update({
'model': f'{model.dataset}-{model.architecture}',
'layer': model.layer,
'dimensions': _dimensions
})
results.append(result)
results_df = pd.DataFrame(results)
results_df.to_csv(output_file, float_format=FLOAT_FORMAT)
from skhubness.neighbors import KNeighborsClassifier
# Fetch data and have a look
d = olivetti_faces.fetch_olivetti_faces()
X, y = d['data'], d['target']
print(f'Data shape: {X.shape}')
print(f'Label shape: {y.shape}')
# (400, 4096)
# (400,)
# The data is embedded in a high-dimensional space.
# Is there hubness, and can we reduce it?
for hubness in [None, 'dsl', 'ls', 'mp']:
hub = Hubness(k=10, hubness=hubness, return_value='k_skewness')
hub.fit(X)
score = hub.score()
print(f'Hubness (10-skew): {score:.3f} with hubness reduction: {hubness}')
# Hubness (10-skew): 1.972 with hubness reduction: None
# Hubness (10-skew): 1.526 with hubness reduction: dsl
# Hubness (10-skew): 0.943 with hubness reduction: ls
# Hubness (10-skew): 0.184 with hubness reduction: mp
# There is some hubness, and all hubness reduction methods can reduce it (to varying degree)
# Let's assess the best kNN strategy and its estimated performance.
cv_perf = StratifiedKFold(n_splits=5, shuffle=True, random_state=7263)
cv_select = StratifiedKFold(n_splits=5, shuffle=True, random_state=32634)
knn = KNeighborsClassifier(algorithm_params={'n_candidates': 100})
# specify parameters and distributions to sample from
param_dist = {"n_neighbors": np.arange(1, 26),
# d_mle = hub_toolbox.intrinsic_dimension.intrinsic_dimension(vectors)
# # vectors = vectors[:10000, :]
# # d_mle = hub_toolbox.intrinsic_dimension.intrinsic_dimension(vectors)
# # vectors = mnist.data
# # vectors = vectors[:10000, :]
# # d_mle = hub_toolbox.intrinsic_dimension.intrinsic_dimension(vectors)
# D = euclidean_distance(vectors)
#
# S_k, _, _ = hub_toolbox.hubness.hubness(D=D, k=5, metric='distance')
# D_mp = hub_toolbox.global_scaling.mutual_proximity_empiric(
# D=D, metric='distance')
# S_k_mp, _, _ = hub_toolbox.hubness.hubness(D=D_mp, k=5, metric='distance')
#
# print(S_k, S_k_mp)
from skhubness.data import load_dexter
X, y = load_dexter()
from skhubness import Hubness
hub = Hubness(k=10, metric='cosine')
hub.fit(X)
k_skew = hub.score()
print(f'Skewness = {k_skew:.3f}')
from skhubness.neighbors import kneighbors_graph
k = 5
# neigbor_graph = kneighbors_graph(X, n_neighbors=k, hubness='mutual_proximity')
neigbor_graph = kneighbors_graph(X, n_neighbors=k, hubness=None)
neighbor_matrix = neigbor_graph.indices.reshape((X.shape[0], k))
print(neighbor_matrix)