def test_arsenal_train_estimate():
"""Test of Arsenal train estimate on unit test data."""
# load unit test data
X_train, y_train = load_unit_test(split="train")
# train Arsenal
arsenal = Arsenal(num_kernels=20,
n_estimators=5,
random_state=0,
save_transformed_data=True)
arsenal.fit(X_train, y_train)
# test train estimate
train_probas = arsenal._get_train_probs(X_train, y_train)
assert train_probas.shape == (20, 2)
train_preds = arsenal.classes_[np.argmax(train_probas, axis=1)]
assert accuracy_score(y_train, train_preds) >= 0.6
def test_arsenal_on_unit_test_data():
"""Test of Arsenal on unit test data."""
# load unit test data
X_train, y_train = load_unit_test(split="train", return_X_y=True)
X_test, y_test = load_unit_test(split="test", return_X_y=True)
indices = np.random.RandomState(0).choice(len(y_train), 10, replace=False)
# train Arsenal
arsenal = Arsenal(num_kernels=500,
n_estimators=5,
random_state=0,
save_transformed_data=True)
arsenal.fit(X_train, y_train)
# assert probabilities are the same
probas = arsenal.predict_proba(X_test.iloc[indices])
testing.assert_array_equal(probas, arsenal_unit_test_probas)
# test train estimate
train_probas = arsenal._get_train_probs(X_train, y_train)
train_preds = arsenal.classes_[np.argmax(train_probas, axis=1)]
assert accuracy_score(y_train, train_preds) >= 0.85
class HIVECOTEV2(BaseClassifier):
"""Hierarchical Vote Collective of Transformation-based Ensembles (HIVE-COTE) V2.
An ensemble of the STC, DrCIF, Arsenal and TDE classifiers from different feature
representations using the CAWPE structure as described in [1].
Parameters
----------
stc_params : dict or None, default=None
Parameters for the ShapeletTransformClassifier module. If None, uses the
default parameters with a 2 hour transform contract.
drcif_params : dict or None, default=None
Parameters for the DrCIF module. If None, uses the default parameters with
n_estimators set to 500.
arsenal_params : dict or None, default=None
Parameters for the Arsenal module. If None, uses the default parameters.
tde_params : dict or None, default=None
Parameters for the TemporalDictionaryEnsemble module. If None, uses the default
parameters.
time_limit_in_minutes : int, default=0
Time contract to limit build time in minutes, overriding
n_estimators/n_parameter_samples for each component.
Default of 0 means n_estimators/n_parameter_samples for each component is used.
save_component_probas : bool, default=False
When predict/predict_proba is called, save each HIVE-COTEV2 component
probability predictions in component_probas.
verbose : int, default=0
Level of output printed to the console (for information only).
n_jobs : int, default=1
The number of jobs to run in parallel for both `fit` and `predict`.
``-1`` means using all processors.
random_state : int or None, default=None
Seed for random number generation.
Attributes
----------
n_classes_ : int
The number of classes.
classes_ : list
The unique class labels.
stc_weight_ : float
The weight for STC probabilities.
drcif_weight_ : float
The weight for DrCIF probabilities.
arsenal_weight_ : float
The weight for Arsenal probabilities.
tde_weight_ : float
The weight for TDE probabilities.
component_probas : dict
Only used if save_component_probas is true. Saved probability predictions for
each HIVE-COTEV2 component.
See Also
--------
HIVECOTEV1, ShapeletTransformClassifier, DrCIF, Arsenal, TemporalDictionaryEnsemble
Notes
-----
For the Java version, see
`https://github.com/uea-machine-learning/tsml/blob/master/src/main/java/
tsml/classifiers/hybrids/HIVE_COTE.java`_.
References
----------
.. [1] Middlehurst, Matthew, James Large, Michael Flynn, Jason Lines, Aaron Bostrom,
and Anthony Bagnall. "HIVE-COTE 2.0: a new meta ensemble for time series
classification." Machine Learning (2021).
Examples
--------
>>> from sktime.classification.hybrid import HIVECOTEV2
>>> from sktime.contrib.vector_classifiers._rotation_forest import RotationForest
>>> from sktime.datasets import load_unit_test
>>> X_train, y_train = load_unit_test(split="train", return_X_y=True)
>>> X_test, y_test = load_unit_test(split="test", return_X_y=True)
>>> clf = HIVECOTEV2(
... stc_params={
... "estimator": RotationForest(n_estimators=3),
... "n_shapelet_samples": 500,
... "max_shapelets": 20,
... "batch_size": 100,
... },
... drcif_params={"n_estimators": 10},
... arsenal_params={"num_kernels": 100, "n_estimators": 5},
... tde_params={
... "n_parameter_samples": 25,
... "max_ensemble_size": 5,
... "randomly_selected_params": 10,
... },
... )
>>> clf.fit(X_train, y_train)
HIVECOTEV2(...)
>>> y_pred = clf.predict(X_test)
"""
_tags = {
"capability:multivariate": True,
"capability:contractable": True,
"capability:multithreading": True,
}
def __init__(
self,
stc_params=None,
drcif_params=None,
arsenal_params=None,
tde_params=None,
time_limit_in_minutes=0,
save_component_probas=False,
verbose=0,
n_jobs=1,
random_state=None,
):
self.stc_params = stc_params
self.drcif_params = drcif_params
self.arsenal_params = arsenal_params
self.tde_params = tde_params
self.time_limit_in_minutes = time_limit_in_minutes
self.save_component_probas = save_component_probas
self.verbose = verbose
self.n_jobs = n_jobs
self.random_state = random_state
self.stc_weight_ = 0
self.drcif_weight_ = 0
self.arsenal_weight_ = 0
self.tde_weight_ = 0
self.component_probas = {}
self._stc_params = stc_params
self._drcif_params = drcif_params
self._arsenal_params = arsenal_params
self._tde_params = tde_params
self._stc = None
self._drcif = None
self._arsenal = None
self._tde = None
super(HIVECOTEV2, self).__init__()
def _fit(self, X, y):
"""Fit HIVE-COTE 2.0 to training data.
Parameters
----------
X : 3D np.array of shape = [n_instances, n_dimensions, series_length]
The training data.
y : array-like, shape = [n_instances]
The class labels.
Returns
-------
self :
Reference to self.
Notes
-----
Changes state by creating a fitted model that updates attributes
ending in "_" and sets is_fitted flag to True.
"""
# Default values from HC2 paper
if self.stc_params is None:
self._stc_params = {"transform_limit_in_minutes": 120}
if self.drcif_params is None:
self._drcif_params = {"n_estimators": 500}
if self.arsenal_params is None:
self._arsenal_params = {}
if self.tde_params is None:
self._tde_params = {}
# If we are contracting split the contract time between each algorithm
if self.time_limit_in_minutes > 0:
# Leave 1/3 for train estimates
ct = self.time_limit_in_minutes / 6
self._stc_params["time_limit_in_minutes"] = ct
self._drcif_params["time_limit_in_minutes"] = ct
self._arsenal_params["time_limit_in_minutes"] = ct
self._tde_params["time_limit_in_minutes"] = ct
# Build STC
self._stc = ShapeletTransformClassifier(
**self._stc_params,
save_transformed_data=True,
random_state=self.random_state,
n_jobs=self._threads_to_use,
)
self._stc.fit(X, y)
if self.verbose > 0:
print("STC ", datetime.now().strftime("%H:%M:%S %d/%m/%Y")) # noqa
# Find STC weight using train set estimate
train_probs = self._stc._get_train_probs(X, y)
train_preds = self._stc.classes_[np.argmax(train_probs, axis=1)]
self.stc_weight_ = accuracy_score(y, train_preds) ** 4
if self.verbose > 0:
print( # noqa
"STC train estimate ",
datetime.now().strftime("%H:%M:%S %d/%m/%Y"),
)
print("STC weight = " + str(self.stc_weight_)) # noqa
# Build DrCIF
self._drcif = DrCIF(
**self._drcif_params,
save_transformed_data=True,
random_state=self.random_state,
n_jobs=self._threads_to_use,
)
self._drcif.fit(X, y)
if self.verbose > 0:
print("DrCIF ", datetime.now().strftime("%H:%M:%S %d/%m/%Y")) # noqa
# Find DrCIF weight using train set estimate
train_probs = self._drcif._get_train_probs(X, y)
train_preds = self._drcif.classes_[np.argmax(train_probs, axis=1)]
self.drcif_weight_ = accuracy_score(y, train_preds) ** 4
if self.verbose > 0:
print( # noqa
"DrCIF train estimate ",
datetime.now().strftime("%H:%M:%S %d/%m/%Y"),
)
print("DrCIF weight = " + str(self.drcif_weight_)) # noqa
# Build Arsenal
self._arsenal = Arsenal(
**self._arsenal_params,
save_transformed_data=True,
random_state=self.random_state,
n_jobs=self._threads_to_use,
)
self._arsenal.fit(X, y)
if self.verbose > 0:
print("Arsenal ", datetime.now().strftime("%H:%M:%S %d/%m/%Y")) # noqa
# Find Arsenal weight using train set estimate
train_probs = self._arsenal._get_train_probs(X, y)
train_preds = self._arsenal.classes_[np.argmax(train_probs, axis=1)]
self.arsenal_weight_ = accuracy_score(y, train_preds) ** 4
if self.verbose > 0:
print( # noqa
"Arsenal train estimate ",
datetime.now().strftime("%H:%M:%S %d/%m/%Y"),
)
print("Arsenal weight = " + str(self.arsenal_weight_)) # noqa
# Build TDE
self._tde = TemporalDictionaryEnsemble(
**self._tde_params,
save_train_predictions=True,
random_state=self.random_state,
n_jobs=self._threads_to_use,
)
self._tde.fit(X, y)
if self.verbose > 0:
print("TDE ", datetime.now().strftime("%H:%M:%S %d/%m/%Y")) # noqa
# Find TDE weight using train set estimate
train_probs = self._tde._get_train_probs(X, y, train_estimate_method="loocv")
train_preds = self._tde.classes_[np.argmax(train_probs, axis=1)]
self.tde_weight_ = accuracy_score(y, train_preds) ** 4
if self.verbose > 0:
print( # noqa
"TDE train estimate ",
datetime.now().strftime("%H:%M:%S %d/%m/%Y"),
)
print("TDE weight = " + str(self.tde_weight_)) # noqa
return self
def _predict(self, X):
"""Predicts labels for sequences in X.
Parameters
----------
X : 3D np.array of shape = [n_instances, n_dimensions, series_length]
The data to make predictions for.
Returns
-------
y : array-like, shape = [n_instances]
Predicted class labels.
"""
rng = check_random_state(self.random_state)
return np.array(
[
self.classes_[int(rng.choice(np.flatnonzero(prob == prob.max())))]
for prob in self.predict_proba(X)
]
)
def _predict_proba(self, X, return_component_probas=False):
"""Predicts labels probabilities for sequences in X.
Parameters
----------
X : 3D np.array of shape = [n_instances, n_dimensions, series_length]
The data to make predict probabilities for.
Returns
-------
y : array-like, shape = [n_instances, n_classes_]
Predicted probabilities using the ordering in classes_.
"""
dists = np.zeros((X.shape[0], self.n_classes_))
# Call predict proba on each classifier, multiply the probabilities by the
# classifiers weight then add them to the current HC2 probabilities
stc_probas = self._stc.predict_proba(X)
dists = np.add(
dists,
stc_probas * (np.ones(self.n_classes_) * self.stc_weight_),
)
drcif_probas = self._drcif.predict_proba(X)
dists = np.add(
dists,
drcif_probas * (np.ones(self.n_classes_) * self.drcif_weight_),
)
arsenal_probas = self._arsenal.predict_proba(X)
dists = np.add(
dists,
arsenal_probas * (np.ones(self.n_classes_) * self.arsenal_weight_),
)
tde_probas = self._tde.predict_proba(X)
dists = np.add(
dists,
tde_probas * (np.ones(self.n_classes_) * self.tde_weight_),
)
if self.save_component_probas:
self.component_probas = {
"STC": stc_probas,
"DrCIF": drcif_probas,
"Arsenal": arsenal_probas,
"TDE": tde_probas,
}
# Make each instances probability array sum to 1 and return
return dists / dists.sum(axis=1, keepdims=True)