Exemplo n.º 1
0
def test_stc_on_unit_test_data():
    """Test of ShapeletTransformClassifier 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 STC
    stc = ShapeletTransformClassifier(
        estimator=RotationForest(n_estimators=3),
        max_shapelets=20,
        n_shapelet_samples=500,
        batch_size=100,
        random_state=0,
        save_transformed_data=True,
    )
    stc.fit(X_train, y_train)

    # assert probabilities are the same
    probas = stc.predict_proba(X_test.iloc[indices])
    testing.assert_array_equal(probas, stc_unit_test_probas)

    # test train estimate
    train_probas = stc._get_train_probs(X_train, y_train)
    train_preds = stc.classes_[np.argmax(train_probas, axis=1)]
    assert accuracy_score(y_train, train_preds) >= 0.75
Exemplo n.º 2
0
def test_stc_on_basic_motions():
    """Test of ShapeletTransformClassifier on basic motions data."""
    # load basic motions data
    X_train, y_train = load_basic_motions(split="train", return_X_y=True)
    X_test, y_test = load_basic_motions(split="test", return_X_y=True)
    indices = np.random.RandomState(4).choice(len(y_train), 15, replace=False)

    # train STC
    stc = ShapeletTransformClassifier(
        estimator=RotationForest(n_estimators=3),
        max_shapelets=20,
        n_shapelet_samples=500,
        batch_size=100,
        random_state=0,
    )
    stc.fit(X_train.iloc[indices], y_train[indices])

    # assert probabilities are the same
    probas = stc.predict_proba(X_test.iloc[indices[:10]])
    testing.assert_array_equal(probas, stc_basic_motions_probas)
Exemplo n.º 3
0
class HIVECOTEV1(BaseClassifier):
    """Hierarchical Vote Collective of Transformation-based Ensembles (HIVE-COTE) V1.

    An ensemble of the STC, TSF, RISE and cBOSS classifiers from different feature
    representations using the CAWPE structure as described in [1].

    Parameters
    ----------
    verbose                 : int, level of output printed to
    the console (for information only) (default = 0)
    n_jobs                  : int, optional (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, seed for random, integer,
    optional (default to no seed)

    Attributes
    ----------
    n_classes               : extracted from the data

    Notes
    -----
    ..[1] Anthony Bagnall, Michael Flynn, James Large, Jason Lines and
    Matthew Middlehurst.
        "On the usage and performance of the Hierarchical Vote Collective of
            Transformation-based Ensembles version 1.0 (hive-cote v1. 0)"
        International Workshop on Advanced Analytics and Learning on Temporal
            Data 2020

    Java version
    https://github.com/uea-machine-learning/tsml/blob/master/src/main/java/
    tsml/classifiers/hybrids/HIVE_COTE.java

    """

    # Capability tags
    capabilities = {
        "multivariate": False,
        "unequal_length": False,
        "missing_values": False,
        "train_estimate": False,
        "contractable": False,
    }

    def __init__(
        self,
        stc_params=None,
        tsf_params=None,
        rise_params=None,
        cboss_params=None,
        verbose=0,
        n_jobs=1,
        random_state=None,
    ):
        if stc_params is None:
            stc_params = {"n_estimators": 500}
        if tsf_params is None:
            tsf_params = {"n_estimators": 500}
        if rise_params is None:
            rise_params = {"n_estimators": 500}
        if cboss_params is None:
            cboss_params = {}

        self.stc_params = stc_params
        self.tsf_params = tsf_params
        self.rise_params = rise_params
        self.cboss_params = cboss_params

        self.verbose = verbose
        self.n_jobs = n_jobs
        self.random_state = random_state

        self.stc = None
        self.tsf = None
        self.rise = None
        self.cboss = None

        self.stc_weight = 0
        self.tsf_weight = 0
        self.rise_weight = 0
        self.cboss_weight = 0

        self.n_classes = 0
        self.classes_ = []

        super(HIVECOTEV1, self).__init__()

    def fit(self, X, y):
        """Fit a HIVE-COTEv1.0 classifier.

        Parameters
        ----------
        X : nested pandas DataFrame of shape [n_instances, 1]
            Nested dataframe with univariate time-series in cells.
        y : array-like, shape = [n_instances] The class labels.

        Returns
        -------
        self : object
        """
        X, y = check_X_y(X, y, enforce_univariate=True)

        self.n_classes = np.unique(y).shape[0]
        self.classes_ = class_distribution(np.asarray(y).reshape(-1, 1))[0][0]

        cv_size = 10
        _, counts = np.unique(y, return_counts=True)
        min_class = np.min(counts)
        if min_class < cv_size:
            cv_size = min_class

        self.stc = ShapeletTransformClassifier(
            **self.stc_params,
            random_state=self.random_state,
        )
        self.stc.fit(X, y)

        if self.verbose > 0:
            print("STC ", datetime.now().strftime("%H:%M:%S %d/%m/%Y"))  # noqa

        train_preds = cross_val_predict(
            ShapeletTransformClassifier(
                **self.stc_params,
                random_state=self.random_state,
            ),
            X=X,
            y=y,
            cv=cv_size,
            n_jobs=self.n_jobs,
        )
        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

        self.tsf = TimeSeriesForestClassifier(
            **self.tsf_params,
            random_state=self.random_state,
            n_jobs=self.n_jobs,
        )
        self.tsf.fit(X, y)

        if self.verbose > 0:
            print("TSF ", datetime.now().strftime("%H:%M:%S %d/%m/%Y"))  # noqa

        train_preds = cross_val_predict(
            TimeSeriesForestClassifier(**self.tsf_params,
                                       random_state=self.random_state),
            X=X,
            y=y,
            cv=cv_size,
            n_jobs=self.n_jobs,
        )
        self.tsf_weight = accuracy_score(y, train_preds)**4

        if self.verbose > 0:
            print(  # noqa
                "TSF train estimate ",
                datetime.now().strftime("%H:%M:%S %d/%m/%Y"),
            )
            print("TSF weight = " + str(self.tsf_weight))  # noqa

        self.rise = RandomIntervalSpectralForest(
            **self.rise_params,
            random_state=self.random_state,
            n_jobs=self.n_jobs,
        )
        self.rise.fit(X, y)

        if self.verbose > 0:
            print("RISE ",
                  datetime.now().strftime("%H:%M:%S %d/%m/%Y"))  # noqa

        train_preds = cross_val_predict(
            RandomIntervalSpectralForest(
                **self.rise_params,
                random_state=self.random_state,
            ),
            X=X,
            y=y,
            cv=cv_size,
            n_jobs=self.n_jobs,
        )
        self.rise_weight = accuracy_score(y, train_preds)**4

        if self.verbose > 0:
            print(  # noqa
                "RISE train estimate ",
                datetime.now().strftime("%H:%M:%S %d/%m/%Y"),
            )
            print("RISE weight = " + str(self.rise_weight))  # noqa

        self.cboss = ContractableBOSS(**self.cboss_params,
                                      random_state=self.random_state,
                                      n_jobs=self.n_jobs)
        self.cboss.fit(X, y)
        train_probs = self.cboss._get_train_probs(X)
        train_preds = self.cboss.classes_[np.argmax(train_probs, axis=1)]
        self.cboss_weight = accuracy_score(y, train_preds)**4

        if self.verbose > 0:
            print(  # noqa
                "cBOSS (estimate included) ",
                datetime.now().strftime("%H:%M:%S %d/%m/%Y"),
            )
            print("cBOSS weight = " + str(self.cboss_weight))  # noqa

        self._is_fitted = True
        return self

    def predict(self, X):
        """Make predictions for all cases in X.

        Parameters
        ----------
        X : The testing input samples of shape [n_instances,1].

        Returns
        -------
        output : numpy array of shape = [n_instances]
        """
        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):
        """Make class probability estimates on each case in X.

        Parameters
        ----------
        X - pandas dataframe of testing data of shape [n_instances,1].

        Returns
        -------
        output : numpy array of shape =
                [n_instances, num_classes] of probabilities
        """
        self.check_is_fitted()
        X = check_X(X, enforce_univariate=True)

        dists = np.zeros((X.shape[0], self.n_classes))

        dists = np.add(
            dists,
            self.stc.predict_proba(X) *
            (np.ones(self.n_classes) * self.stc_weight),
        )
        dists = np.add(
            dists,
            self.tsf.predict_proba(X) *
            (np.ones(self.n_classes) * self.tsf_weight),
        )
        dists = np.add(
            dists,
            self.rise.predict_proba(X) *
            (np.ones(self.n_classes) * self.rise_weight),
        )
        dists = np.add(
            dists,
            self.cboss.predict_proba(X) *
            (np.ones(self.n_classes) * self.cboss_weight),
        )

        return dists / dists.sum(axis=1, keepdims=True)
Exemplo n.º 4
0
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)
Exemplo n.º 5
0
class HIVECOTEV1(BaseClassifier):
    """
    Hierarchical Vote Collective of Transformation-based Ensembles (HIVE-COTE) V1
    as described in [1].

    An ensemble of the STC, TSF, RISE and cBOSS classifiers from different feature
    representations using the CAWPE structure.


    Parameters
    ----------
    random_state            : int or None, seed for random, integer,
    optional (default to no seed)

    Attributes
    ----------
    n_classes               : extracted from the data

    Notes
    -----
    @article{bagnall2020usage,
      title={On the Usage and Performance of The Hierarchical Vote Collective of
      Transformation-based Ensembles version 1.0 (HIVE-COTE 1.0)},
      author={Bagnall, Anthony and Flynn, Michael and Large, James and Lines, Jason and
      Middlehurst, Matthew},
      journal={arXiv preprint arXiv:2004.06069},
      year={2020}
    }

    Java version
    https://github.com/uea-machine-learning/tsml/blob/master/src/main/java/
    tsml/classifiers/hybrids/HIVE_COTE.java

    """

    # Capability tags
    capabilities = {
        "multivariate": False,
        "unequal_length": False,
        "missing_values": False,
    }

    def __init__(
        self,
        random_state=None,
    ):
        self.random_state = random_state

        self.stc = None
        self.tsf = None
        self.rise = None
        self.cboss = None

        self.stc_weight = 0
        self.tsf_weight = 0
        self.rise_weight = 0
        self.cboss_weight = 0

        self.n_classes = 0
        self.classes_ = []

        super(HIVECOTEV1, self).__init__()

    def fit(self, X, y):
        X, y = check_X_y(X, y, enforce_univariate=True, coerce_to_numpy=True)

        self.n_classes = np.unique(y).shape[0]
        self.classes_ = class_distribution(np.asarray(y).reshape(-1, 1))[0][0]

        cv_size = 10
        _, counts = np.unique(y, return_counts=True)
        min_class = np.min(counts)
        if min_class < cv_size:
            cv_size = min_class

        self.stc = ShapeletTransformClassifier(
            random_state=self.random_state,
            time_contract_in_mins=60,
        )
        self.stc.fit(X, y)
        train_preds = cross_val_predict(
            ShapeletTransformClassifier(
                random_state=self.random_state,
                time_contract_in_mins=60,
            ),
            X=X,
            y=y,
            cv=cv_size,
        )
        self.stc_weight = accuracy_score(y, train_preds)**4

        self.tsf = TimeSeriesForest(random_state=self.random_state)
        self.tsf.fit(X, y)
        train_preds = cross_val_predict(
            TimeSeriesForest(random_state=self.random_state),
            X=X,
            y=y,
            cv=cv_size,
        )
        self.tsf_weight = accuracy_score(y, train_preds)**4

        self.rise = RandomIntervalSpectralForest(
            random_state=self.random_state)
        self.fit(X, y)
        train_preds = cross_val_predict(
            RandomIntervalSpectralForest(random_state=self.random_state),
            X=X,
            y=y,
            cv=cv_size,
        )
        self.rise_weight = accuracy_score(y, train_preds)**4

        self.cboss = ContractableBOSS(random_state=self.random_state)
        self.cboss.fit(X, y)
        train_probs = self.cboss._get_train_probs(X)
        train_preds = self.cboss.classes_[np.argmax(train_probs, axis=1)]
        self.cboss_weight = accuracy_score(y, train_preds)**4

        return self

    def predict(self, X):
        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):
        self.check_is_fitted()
        X = check_X(X, enforce_univariate=True, coerce_to_numpy=True)

        dists = np.zeros((X.shape[0], self.n_classes))

        dists = np.add(
            dists,
            self.stc.predict_proba(X) *
            (np.ones(self.n_classes) * self.stc_weight),
        )
        dists = np.add(
            dists,
            self.tsf.predict_proba(X) *
            (np.ones(self.n_classes) * self.tsf_weight),
        )
        dists = np.add(
            dists,
            self.rise.predict_proba(X) *
            (np.ones(self.n_classes) * self.rise_weight),
        )
        dists = np.add(
            dists,
            self.cboss.predict_proba(X) *
            (np.ones(self.n_classes) * self.cboss_weight),
        )

        return dists / dists.sum(axis=1, keepdims=True)
Exemplo n.º 6
0
class HIVECOTEV1(BaseClassifier):
    """Hierarchical Vote Collective of Transformation-based Ensembles (HIVE-COTE) V1.

    An ensemble of the STC, TSF, RISE and cBOSS 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.
    tsf_params : dict or None, default=None
        Parameters for the TimeSeriesForestClassifier module. If None, uses the default
        parameters with n_estimators set to 500.
    rise_params : dict or None, default=None
        Parameters for the RandomIntervalSpectralForest module. If None, uses the
        default parameters with n_estimators set to 500.
    cboss_params : dict or None, default=None
        Parameters for the ContractableBOSS module. If None, uses the default
        parameters.
    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.
    tsf_weight_ : float
        The weight for TSF probabilities.
    rise_weight_ : float
        The weight for RISE probabilities.
    cboss_weight_ : float
        The weight for cBOSS probabilities.

    See Also
    --------
    HIVECOTEV2, ShapeletTransformClassifier, TimeSeriesForestClassifier,
    RandomIntervalSpectralForest, ContractableBOSS

    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] Anthony Bagnall, Michael Flynn, James Large, Jason Lines and
       Matthew Middlehurst. "On the usage and performance of the Hierarchical Vote
       Collective of Transformation-based Ensembles version 1.0 (hive-cote v1.0)"
       International Workshop on Advanced Analytics and Learning on Temporal Data 2020

    Examples
    --------
    >>> from sktime.classification.hybrid import HIVECOTEV1
    >>> 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 = HIVECOTEV1(
    ...     stc_params={
    ...         "estimator": RotationForest(n_estimators=3),
    ...         "n_shapelet_samples": 500,
    ...         "max_shapelets": 20,
    ...         "batch_size": 100,
    ...     },
    ...     tsf_params={"n_estimators": 10},
    ...     rise_params={"n_estimators": 10},
    ...     cboss_params={"n_parameter_samples": 25, "max_ensemble_size": 5},
    ... )
    >>> clf.fit(X_train, y_train)
    HIVECOTEV1(...)
    >>> y_pred = clf.predict(X_test)
    """

    _tags = {
        "capability:multithreading": True,
    }

    def __init__(
        self,
        stc_params=None,
        tsf_params=None,
        rise_params=None,
        cboss_params=None,
        verbose=0,
        n_jobs=1,
        random_state=None,
    ):
        self.stc_params = stc_params
        self.tsf_params = tsf_params
        self.rise_params = rise_params
        self.cboss_params = cboss_params

        self.verbose = verbose
        self.n_jobs = n_jobs
        self.random_state = random_state

        self.stc_weight_ = 0
        self.tsf_weight_ = 0
        self.rise_weight_ = 0
        self.cboss_weight_ = 0

        self._stc_params = stc_params
        self._tsf_params = tsf_params
        self._rise_params = rise_params
        self._cboss_params = cboss_params
        self._stc = None
        self._tsf = None
        self._rise = None
        self._cboss = None

        super(HIVECOTEV1, self).__init__()

    def _fit(self, X, y):
        """Fit HIVE-COTE 1.0 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 HC1 paper
        if self.stc_params is None:
            self._stc_params = {"transform_limit_in_minutes": 120}
        if self.tsf_params is None:
            self._tsf_params = {"n_estimators": 500}
        if self.rise_params is None:
            self._rise_params = {"n_estimators": 500}
        if self.cboss_params is None:
            self._cboss_params = {}

        # Cross-validation size for TSF and RISE
        cv_size = 10
        _, counts = np.unique(y, return_counts=True)
        min_class = np.min(counts)
        if min_class < cv_size:
            cv_size = min_class

        # 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 TSF
        self._tsf = TimeSeriesForestClassifier(
            **self._tsf_params,
            random_state=self.random_state,
            n_jobs=self._threads_to_use,
        )
        self._tsf.fit(X, y)

        if self.verbose > 0:
            print("TSF ", datetime.now().strftime("%H:%M:%S %d/%m/%Y"))  # noqa

        # Find TSF weight using train set estimate found through CV
        train_preds = cross_val_predict(
            TimeSeriesForestClassifier(**self._tsf_params,
                                       random_state=self.random_state),
            X=X,
            y=y,
            cv=cv_size,
            n_jobs=self._threads_to_use,
        )
        self.tsf_weight_ = accuracy_score(y, train_preds)**4

        if self.verbose > 0:
            print(  # noqa
                "TSF train estimate ",
                datetime.now().strftime("%H:%M:%S %d/%m/%Y"),
            )
            print("TSF weight = " + str(self.tsf_weight_))  # noqa

        # Build RISE
        self._rise = RandomIntervalSpectralEnsemble(
            **self._rise_params,
            random_state=self.random_state,
            n_jobs=self._threads_to_use,
        )
        self._rise.fit(X, y)

        if self.verbose > 0:
            print("RISE ",
                  datetime.now().strftime("%H:%M:%S %d/%m/%Y"))  # noqa

        # Find RISE weight using train set estimate found through CV
        train_preds = cross_val_predict(
            RandomIntervalSpectralEnsemble(
                **self._rise_params,
                random_state=self.random_state,
            ),
            X=X,
            y=y,
            cv=cv_size,
            n_jobs=self._threads_to_use,
        )
        self.rise_weight_ = accuracy_score(y, train_preds)**4

        if self.verbose > 0:
            print(  # noqa
                "RISE train estimate ",
                datetime.now().strftime("%H:%M:%S %d/%m/%Y"),
            )
            print("RISE weight = " + str(self.rise_weight_))  # noqa

        # Build cBOSS
        self._cboss = ContractableBOSS(
            **self._cboss_params,
            random_state=self.random_state,
            n_jobs=self._threads_to_use,
        )
        self._cboss.fit(X, y)

        # Find cBOSS weight using train set estimate
        train_probs = self._cboss._get_train_probs(X, y)
        train_preds = self._cboss.classes_[np.argmax(train_probs, axis=1)]
        self.cboss_weight_ = accuracy_score(y, train_preds)**4

        if self.verbose > 0:
            print(  # noqa
                "cBOSS (estimate included)",
                datetime.now().strftime("%H:%M:%S %d/%m/%Y"),
            )
            print("cBOSS weight = " + str(self.cboss_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):
        """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 HC1 probabilities
        dists = np.add(
            dists,
            self._stc.predict_proba(X) *
            (np.ones(self.n_classes_) * self.stc_weight_),
        )
        dists = np.add(
            dists,
            self._tsf.predict_proba(X) *
            (np.ones(self.n_classes_) * self.tsf_weight_),
        )
        dists = np.add(
            dists,
            self._rise.predict_proba(X) *
            (np.ones(self.n_classes_) * self.rise_weight_),
        )
        dists = np.add(
            dists,
            self._cboss.predict_proba(X) *
            (np.ones(self.n_classes_) * self.cboss_weight_),
        )

        # Make each instances probability array sum to 1 and return
        return dists / dists.sum(axis=1, keepdims=True)