def neighbor_cluster(AMDs_train, AMDs_test, energy_train, energy_test, type):
energy_test_pred = []
N = 15
if type == "chebyshev":
tree = BallTree(AMDs_train, metric='chebyshev')
elif type == "euclidean":
tree = BallTree(AMDs_train, metric='euclidean')
elif type == "minkowski":
tree = BallTree(AMDs_train, metric='minkowski')
elif type == "manhattan":
tree = BallTree(AMDs_train, metric='manhattan')
else:
return
dist, inds = tree.query(AMDs_test, k=N)
for ind in inds:
sum = 0
for i in ind:
sum += energy_train[i]
ave = sum / N
energy_test_pred.append(ave)
fig, ax = plt.subplots()
print("R^2 score of KNN is: ", r2_score(energy_test, energy_test_pred))
print("RMSE of KNN is: ",
math.sqrt(mean_squared_error(energy_test, energy_test_pred)))
ax.scatter(energy_test, energy_test_pred)
ax.plot([np.min(energy_test), np.max(energy_test)],
[np.min(energy_test), np.max(energy_test)],
'k--',
lw=4)
ax.set_xlabel('Given')
ax.set_ylabel('Predicted')
plt.savefig('./image/knn_' + type + '.jpg')
def test_query_haversine():
rng = check_random_state(0)
X = 2 * np.pi * rng.random_sample((40, 2))
bt = BallTree(X, leaf_size=1, metric="haversine")
dist1, ind1 = bt.query(X, k=5)
dist2, ind2 = brute_force_neighbors(X, X, k=5, metric="haversine")
assert_array_almost_equal(dist1, dist2)
assert_array_almost_equal(ind1, ind2)
def NCM(o, Z_T):
Y = np.c_[o, Z_T]
# print(Y.T[:1])
tree = BallTree(Y.T, leaf_size=3)
dist, ind = tree.query(Y.T[:1], k=self.k + 1)
# print(ind) # indices of k closest neighbors
# print(dist) # distances to k closest neighbors
# print(dist.sum())
return dist.sum()
def find_target_neighbors(X, labels, K, n_classes):
N, D = X.shape
targets_ind = np.zeros((N, K), dtype=int)
for i in range(n_classes):
jj, = np.where(labels == i)
# Samples of the class i
Xu = X[jj]
kdt = BallTree(Xu, leaf_size=50, metric='euclidean')
targets = kdt.query(Xu, k=K + 1, return_distance=False)
targets_ind[jj] = jj[targets[:, 1:]]
return targets_ind
def get_closest_locations(data,
query_lon,
query_lat,
query_cat=None,
query_subcat=None,
num_locs=10):
bt_lons = []
bt_lats = []
bt_indices = []
for n, entry in enumerate(data):
valid = True
if query_cat is not None and not (query_cat.lower().strip(
) in entry["mapping"]["top_category"].lower().strip()):
valid = False
if query_subcat is not None and not (query_subcat.lower().strip(
) in entry["mapping"]["sub_category"].lower().strip()):
valid = False
if not valid:
break
lon = float(entry["mapping"]["longitude"])
lat = float(entry["mapping"]["latitude"])
bt_lons.append(lon)
bt_lats.append(lat)
bt_indices.append(n)
bt_lons = np.array(bt_lons)
bt_lats = np.array(bt_lats)
bt_indices = np.array(bt_indices)
num_locs = min(num_locs, len(bt_indices))
if num_locs == 0:
return []
records = pd.DataFrame(data={
'lon': bt_lons,
'lat': bt_lats,
'index': bt_indices
})
bt = BallTree(np.deg2rad(records[['lat', 'lon']].values),
metric='haversine')
distances, indices = bt.query(np.deg2rad(np.c_[query_lat, query_lon]),
num_locs)
data_indices = bt_indices[indices[0]].tolist()
return data_indices
def test_ball_tree_kde(kernel, h, rtol, atol, breadth_first, n_samples=100,
n_features=3):
rng = np.random.RandomState(0)
X = rng.random_sample((n_samples, n_features))
Y = rng.random_sample((n_samples, n_features))
bt = BallTree(X, leaf_size=10)
dens_true = compute_kernel_slow(Y, X, kernel, h)
dens = bt.kernel_density(Y, h, atol=atol, rtol=rtol,
kernel=kernel,
breadth_first=breadth_first)
assert_allclose(dens, dens_true,
atol=atol, rtol=max(rtol, 1e-7))
def test_ball_tree_query_metrics(metric):
rng = check_random_state(0)
if metric in BOOLEAN_METRICS:
X = rng.random_sample((40, 10)).round(0)
Y = rng.random_sample((10, 10)).round(0)
elif metric in DISCRETE_METRICS:
X = (4 * rng.random_sample((40, 10))).round(0)
Y = (4 * rng.random_sample((10, 10))).round(0)
k = 5
bt = BallTree(X, leaf_size=1, metric=metric)
dist1, ind1 = bt.query(Y, k)
dist2, ind2 = brute_force_neighbors(X, Y, k, metric)
assert_array_almost_equal(dist1, dist2)
def test_gaussian_kde(n_samples=1000):
# Compare gaussian KDE results to scipy.stats.gaussian_kde
from scipy.stats import gaussian_kde
rng = check_random_state(0)
x_in = rng.normal(0, 1, n_samples)
x_out = np.linspace(-5, 5, 30)
for h in [0.01, 0.1, 1]:
bt = BallTree(x_in[:, None])
gkde = gaussian_kde(x_in, bw_method=h / np.std(x_in))
dens_bt = bt.kernel_density(x_out[:, None], h) / n_samples
dens_gkde = gkde.evaluate(x_out)
assert_array_almost_equal(dens_bt, dens_gkde, decimal=3)
def test_bad_pyfunc_metric():
def wrong_returned_value(x, y):
return "1"
def one_arg_func(x):
return 1.0 # pragma: no cover
X = np.ones((5, 2))
msg = "Custom distance function must accept two vectors and return a float."
with pytest.raises(TypeError, match=msg):
BallTree(X, metric=wrong_returned_value)
msg = "takes 1 positional argument but 2 were given"
with pytest.raises(TypeError, match=msg):
BallTree(X, metric=one_arg_func)
def find_impostors(pred, labels, n_classes, no_potential_impo):
N = len(pred)
active = np.zeros((N, no_potential_impo), dtype=int)
for i in range(n_classes):
ii, = np.where(labels == i)
pi = pred[ii]
jj, = np.where(labels != i)
pj = pred[jj]
# Find the nearest neighbors using a BallTree
kdt = BallTree(pj, leaf_size=50, metric='euclidean')
hardest_examples = kdt.query(pi,
k=no_potential_impo,
return_distance=False)
active[ii] = jj[hardest_examples]
return active
def test_ball_tree_query_radius(n_samples=100, n_features=10):
rng = check_random_state(0)
X = 2 * rng.random_sample(size=(n_samples, n_features)) - 1
query_pt = np.zeros(n_features, dtype=float)
eps = 1E-15 # roundoff error can cause test to fail
bt = BallTree(X, leaf_size=5)
rad = np.sqrt(((X - query_pt)**2).sum(1))
for r in np.linspace(rad[0], rad[-1], 100):
ind = bt.query_radius([query_pt], r + eps)[0]
i = np.where(rad <= r + eps)[0]
ind.sort()
i.sort()
assert_array_almost_equal(i, ind)
def test_ball_tree_query_radius_distance(n_samples=100, n_features=10):
rng = check_random_state(0)
X = 2 * rng.random_sample(size=(n_samples, n_features)) - 1
query_pt = np.zeros(n_features, dtype=float)
eps = 1E-15 # roundoff error can cause test to fail
bt = BallTree(X, leaf_size=5)
rad = np.sqrt(((X - query_pt)**2).sum(1))
for r in np.linspace(rad[0], rad[-1], 100):
ind, dist = bt.query_radius([query_pt], r + eps, return_distance=True)
ind = ind[0]
dist = dist[0]
d = np.sqrt(((query_pt - X[ind])**2).sum(1))
assert_array_almost_equal(d, dist)
def knn_error_score(L, x_train, y_train, x_test, y_test, k, tree_size=15):
"""
Measures the training and testing errors of a kNN classifier implemented using BallTree.
:param L: linear transformation
:param x_train: training vectors (each column is an instance)
:param y_train: training labels (row vector!!)
:param x_test: test vectors
:param y_test: test labels
:param k: number of nearest neighbors
:return: training and testing error in k-NN problem.
"""
assert y_train.ndim == 1, y_test.ndim == 1
assert x_train.shape[0] == len(y_train)
assert x_test.shape[0] == len(y_test)
assert isinstance(k, (int, np.int32, np.int64)) and k > 0
if len(L) != 0:
# L is the initial linear projection, for example PCa or LDA
x_train = x_train @ L.T
x_test = x_test @ L.T
tree = BallTree(x_train, leaf_size=tree_size, metric='euclidean')
MM = np.append(y_train, y_test).min()
NTr, NTe = x_train.shape[0], x_test.shape[0]
# Use the tree to compute the distance between the testing and training points
# iTe: indices of the testing elements in the training set
dists, iTe = tree.query(x_test, k=k, return_distance=True)
# Labels of the testing elements in the training set
lTe2 = LSKnn2(y_train[iTe], k, MM)
# Compute the error for each k
test_error = np.sum(lTe2 != np.repeat(y_test, k, axis=0), axis=1) / NTe
# Use the tree to compute the distance between the training points
dists, iTr = tree.query(x_train, k=k + 1, return_distance=True)
iTr = iTr[:, 1:]
lTr2 = LSKnn2(y_train[iTr], k, MM)
training_error = np.sum(lTr2 != np.repeat(y_train, k, axis=0), axis=1) / NTr
return float(training_error), float(test_error)
def test_ball_tree_two_point(n_samples=100, n_features=3):
rng = check_random_state(0)
X = rng.random_sample((n_samples, n_features))
Y = rng.random_sample((n_samples, n_features))
r = np.linspace(0, 1, 10)
bt = BallTree(X, leaf_size=10)
D = DistanceMetric.get_metric("euclidean").pairwise(Y, X)
counts_true = [(D <= ri).sum() for ri in r]
def check_two_point(r, dualtree):
counts = bt.two_point_correlation(Y, r=r, dualtree=dualtree)
assert_array_almost_equal(counts, counts_true)
for dualtree in (True, False):
check_two_point(r, dualtree)
def test_array_object_type():
"""Check that we do not accept object dtype array."""
X = np.array([(1, 2, 3), (2, 5), (5, 5, 1, 2)], dtype=object)
with pytest.raises(ValueError,
match="setting an array element with a sequence"):
BallTree(X)
def fit(self, X, y):
if Version(sklearn_version) >= Version("1.0"):
self._check_feature_names(X, reset=True)
if self.metric_params is not None and 'p' in self.metric_params:
if self.p is not None:
warnings.warn(
"Parameter p is found in metric_params. "
"The corresponding parameter from __init__ "
"is ignored.",
SyntaxWarning,
stacklevel=2)
self.effective_metric_params_ = self.metric_params.copy()
effective_p = self.metric_params["p"]
else:
self.effective_metric_params_ = {}
effective_p = self.p
if self.metric in ["minkowski"]:
if effective_p < 1:
raise ValueError(
"p must be greater or equal to one for minkowski metric")
self.effective_metric_params_["p"] = effective_p
self.effective_metric_ = self.metric
# For minkowski distance, use more efficient methods where available
if self.metric == "minkowski":
p = self.effective_metric_params_.pop("p", 2)
if p < 1:
raise ValueError(
"p must be greater or equal to one for minkowski metric")
if p == 1:
self.effective_metric_ = "manhattan"
elif p == 2:
self.effective_metric_ = "euclidean"
elif p == np.inf:
self.effective_metric_ = "chebyshev"
else:
self.effective_metric_params_["p"] = p
if self.metric == "manhattan":
self.p = 1
if not isinstance(X, (KDTree, BallTree, sklearn_NeighborsBase)):
self._fit_X = _check_array(X,
dtype=[np.float64, np.float32],
accept_sparse=True)
self.n_samples_fit_ = _num_samples(self._fit_X)
self.n_features_in_ = _num_features(self._fit_X)
if self.algorithm == "auto":
# A tree approach is better for small number of neighbors or small
# number of features, with KDTree generally faster when available
is_n_neighbors_valid_for_brute = self.n_neighbors is not None and \
self.n_neighbors >= self._fit_X.shape[0] // 2
if self._fit_X.shape[1] > 15 or is_n_neighbors_valid_for_brute:
self._fit_method = "brute"
else:
if self.effective_metric_ in VALID_METRICS["kd_tree"]:
self._fit_method = "kd_tree"
elif callable(self.effective_metric_) or \
self.effective_metric_ in \
VALID_METRICS["ball_tree"]:
self._fit_method = "ball_tree"
else:
self._fit_method = "brute"
else:
self._fit_method = self.algorithm
if hasattr(self, '_onedal_estimator'):
delattr(self, '_onedal_estimator')
# To cover test case when we pass patched
# estimator as an input for other estimator
if isinstance(X, sklearn_NeighborsBase):
self._fit_X = X._fit_X
self._tree = X._tree
self._fit_method = X._fit_method
self.n_samples_fit_ = X.n_samples_fit_
self.n_features_in_ = X.n_features_in_
if hasattr(X, '_onedal_estimator'):
if self._fit_method == "ball_tree":
X._tree = BallTree(
X._fit_X,
self.leaf_size,
metric=self.effective_metric_,
**self.effective_metric_params_,
)
elif self._fit_method == "kd_tree":
X._tree = KDTree(
X._fit_X,
self.leaf_size,
metric=self.effective_metric_,
**self.effective_metric_params_,
)
elif self._fit_method == "brute":
X._tree = None
else:
raise ValueError("algorithm = '%s' not recognized" %
self.algorithm)
elif isinstance(X, BallTree):
self._fit_X = X.data
self._tree = X
self._fit_method = 'ball_tree'
self.n_samples_fit_ = X.data.shape[0]
self.n_features_in_ = X.data.shape[1]
elif isinstance(X, KDTree):
self._fit_X = X.data
self._tree = X
self._fit_method = 'kd_tree'
self.n_samples_fit_ = X.data.shape[0]
self.n_features_in_ = X.data.shape[1]
dispatch(
self, 'neighbors.KNeighborsClassifier.fit', {
'onedal': self.__class__._onedal_fit,
'sklearn': sklearn_KNeighborsClassifier.fit,
}, X, y)
return self
