reconnect moved files to git repo

venv/lib/python3.11/site-packages/sklearn/cluster/_birch.py

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+# Authors: Manoj Kumar <manojkumarsivaraj334@gmail.com>
+#          Alexandre Gramfort <alexandre.gramfort@telecom-paristech.fr>
+#          Joel Nothman <joel.nothman@gmail.com>
+# License: BSD 3 clause
+
+import warnings
+from math import sqrt
+from numbers import Integral, Real
+
+import numpy as np
+from scipy import sparse
+
+from .._config import config_context
+from ..base import (
+    BaseEstimator,
+    ClassNamePrefixFeaturesOutMixin,
+    ClusterMixin,
+    TransformerMixin,
+    _fit_context,
+)
+from ..exceptions import ConvergenceWarning
+from ..metrics import pairwise_distances_argmin
+from ..metrics.pairwise import euclidean_distances
+from ..utils._param_validation import Interval
+from ..utils.extmath import row_norms
+from ..utils.validation import check_is_fitted
+from . import AgglomerativeClustering
+
+
+def _iterate_sparse_X(X):
+    """This little hack returns a densified row when iterating over a sparse
+    matrix, instead of constructing a sparse matrix for every row that is
+    expensive.
+    """
+    n_samples = X.shape[0]
+    X_indices = X.indices
+    X_data = X.data
+    X_indptr = X.indptr
+
+    for i in range(n_samples):
+        row = np.zeros(X.shape[1])
+        startptr, endptr = X_indptr[i], X_indptr[i + 1]
+        nonzero_indices = X_indices[startptr:endptr]
+        row[nonzero_indices] = X_data[startptr:endptr]
+        yield row
+
+
+def _split_node(node, threshold, branching_factor):
+    """The node has to be split if there is no place for a new subcluster
+    in the node.
+    1. Two empty nodes and two empty subclusters are initialized.
+    2. The pair of distant subclusters are found.
+    3. The properties of the empty subclusters and nodes are updated
+       according to the nearest distance between the subclusters to the
+       pair of distant subclusters.
+    4. The two nodes are set as children to the two subclusters.
+    """
+    new_subcluster1 = _CFSubcluster()
+    new_subcluster2 = _CFSubcluster()
+    new_node1 = _CFNode(
+        threshold=threshold,
+        branching_factor=branching_factor,
+        is_leaf=node.is_leaf,
+        n_features=node.n_features,
+        dtype=node.init_centroids_.dtype,
+    )
+    new_node2 = _CFNode(
+        threshold=threshold,
+        branching_factor=branching_factor,
+        is_leaf=node.is_leaf,
+        n_features=node.n_features,
+        dtype=node.init_centroids_.dtype,
+    )
+    new_subcluster1.child_ = new_node1
+    new_subcluster2.child_ = new_node2
+
+    if node.is_leaf:
+        if node.prev_leaf_ is not None:
+            node.prev_leaf_.next_leaf_ = new_node1
+        new_node1.prev_leaf_ = node.prev_leaf_
+        new_node1.next_leaf_ = new_node2
+        new_node2.prev_leaf_ = new_node1
+        new_node2.next_leaf_ = node.next_leaf_
+        if node.next_leaf_ is not None:
+            node.next_leaf_.prev_leaf_ = new_node2
+
+    dist = euclidean_distances(
+        node.centroids_, Y_norm_squared=node.squared_norm_, squared=True
+    )
+    n_clusters = dist.shape[0]
+
+    farthest_idx = np.unravel_index(dist.argmax(), (n_clusters, n_clusters))
+    node1_dist, node2_dist = dist[(farthest_idx,)]
+
+    node1_closer = node1_dist < node2_dist
+    # make sure node1 is closest to itself even if all distances are equal.
+    # This can only happen when all node.centroids_ are duplicates leading to all
+    # distances between centroids being zero.
+    node1_closer[farthest_idx[0]] = True
+
+    for idx, subcluster in enumerate(node.subclusters_):
+        if node1_closer[idx]:
+            new_node1.append_subcluster(subcluster)
+            new_subcluster1.update(subcluster)
+        else:
+            new_node2.append_subcluster(subcluster)
+            new_subcluster2.update(subcluster)
+    return new_subcluster1, new_subcluster2
+
+
+class _CFNode:
+    """Each node in a CFTree is called a CFNode.
+
+    The CFNode can have a maximum of branching_factor
+    number of CFSubclusters.
+
+    Parameters
+    ----------
+    threshold : float
+        Threshold needed for a new subcluster to enter a CFSubcluster.
+
+    branching_factor : int
+        Maximum number of CF subclusters in each node.
+
+    is_leaf : bool
+        We need to know if the CFNode is a leaf or not, in order to
+        retrieve the final subclusters.
+
+    n_features : int
+        The number of features.
+
+    Attributes
+    ----------
+    subclusters_ : list
+        List of subclusters for a particular CFNode.
+
+    prev_leaf_ : _CFNode
+        Useful only if is_leaf is True.
+
+    next_leaf_ : _CFNode
+        next_leaf. Useful only if is_leaf is True.
+        the final subclusters.
+
+    init_centroids_ : ndarray of shape (branching_factor + 1, n_features)
+        Manipulate ``init_centroids_`` throughout rather than centroids_ since
+        the centroids are just a view of the ``init_centroids_`` .
+
+    init_sq_norm_ : ndarray of shape (branching_factor + 1,)
+        manipulate init_sq_norm_ throughout. similar to ``init_centroids_``.
+
+    centroids_ : ndarray of shape (branching_factor + 1, n_features)
+        View of ``init_centroids_``.
+
+    squared_norm_ : ndarray of shape (branching_factor + 1,)
+        View of ``init_sq_norm_``.
+
+    """
+
+    def __init__(self, *, threshold, branching_factor, is_leaf, n_features, dtype):
+        self.threshold = threshold
+        self.branching_factor = branching_factor
+        self.is_leaf = is_leaf
+        self.n_features = n_features
+
+        # The list of subclusters, centroids and squared norms
+        # to manipulate throughout.
+        self.subclusters_ = []
+        self.init_centroids_ = np.zeros((branching_factor + 1, n_features), dtype=dtype)
+        self.init_sq_norm_ = np.zeros((branching_factor + 1), dtype)
+        self.squared_norm_ = []
+        self.prev_leaf_ = None
+        self.next_leaf_ = None
+
+    def append_subcluster(self, subcluster):
+        n_samples = len(self.subclusters_)
+        self.subclusters_.append(subcluster)
+        self.init_centroids_[n_samples] = subcluster.centroid_
+        self.init_sq_norm_[n_samples] = subcluster.sq_norm_
+
+        # Keep centroids and squared norm as views. In this way
+        # if we change init_centroids and init_sq_norm_, it is
+        # sufficient,
+        self.centroids_ = self.init_centroids_[: n_samples + 1, :]
+        self.squared_norm_ = self.init_sq_norm_[: n_samples + 1]
+
+    def update_split_subclusters(self, subcluster, new_subcluster1, new_subcluster2):
+        """Remove a subcluster from a node and update it with the
+        split subclusters.
+        """
+        ind = self.subclusters_.index(subcluster)
+        self.subclusters_[ind] = new_subcluster1
+        self.init_centroids_[ind] = new_subcluster1.centroid_
+        self.init_sq_norm_[ind] = new_subcluster1.sq_norm_
+        self.append_subcluster(new_subcluster2)
+
+    def insert_cf_subcluster(self, subcluster):
+        """Insert a new subcluster into the node."""
+        if not self.subclusters_:
+            self.append_subcluster(subcluster)
+            return False
+
+        threshold = self.threshold
+        branching_factor = self.branching_factor
+        # We need to find the closest subcluster among all the
+        # subclusters so that we can insert our new subcluster.
+        dist_matrix = np.dot(self.centroids_, subcluster.centroid_)
+        dist_matrix *= -2.0
+        dist_matrix += self.squared_norm_
+        closest_index = np.argmin(dist_matrix)
+        closest_subcluster = self.subclusters_[closest_index]
+
+        # If the subcluster has a child, we need a recursive strategy.
+        if closest_subcluster.child_ is not None:
+            split_child = closest_subcluster.child_.insert_cf_subcluster(subcluster)
+
+            if not split_child:
+                # If it is determined that the child need not be split, we
+                # can just update the closest_subcluster
+                closest_subcluster.update(subcluster)
+                self.init_centroids_[closest_index] = self.subclusters_[
+                    closest_index
+                ].centroid_
+                self.init_sq_norm_[closest_index] = self.subclusters_[
+                    closest_index
+                ].sq_norm_
+                return False
+
+            # things not too good. we need to redistribute the subclusters in
+            # our child node, and add a new subcluster in the parent
+            # subcluster to accommodate the new child.
+            else:
+                new_subcluster1, new_subcluster2 = _split_node(
+                    closest_subcluster.child_,
+                    threshold,
+                    branching_factor,
+                )
+                self.update_split_subclusters(
+                    closest_subcluster, new_subcluster1, new_subcluster2
+                )
+
+                if len(self.subclusters_) > self.branching_factor:
+                    return True
+                return False
+
+        # good to go!
+        else:
+            merged = closest_subcluster.merge_subcluster(subcluster, self.threshold)
+            if merged:
+                self.init_centroids_[closest_index] = closest_subcluster.centroid_
+                self.init_sq_norm_[closest_index] = closest_subcluster.sq_norm_
+                return False
+
+            # not close to any other subclusters, and we still
+            # have space, so add.
+            elif len(self.subclusters_) < self.branching_factor:
+                self.append_subcluster(subcluster)
+                return False
+
+            # We do not have enough space nor is it closer to an
+            # other subcluster. We need to split.
+            else:
+                self.append_subcluster(subcluster)
+                return True
+
+
+class _CFSubcluster:
+    """Each subcluster in a CFNode is called a CFSubcluster.
+
+    A CFSubcluster can have a CFNode has its child.
+
+    Parameters
+    ----------
+    linear_sum : ndarray of shape (n_features,), default=None
+        Sample. This is kept optional to allow initialization of empty
+        subclusters.
+
+    Attributes
+    ----------
+    n_samples_ : int
+        Number of samples that belong to each subcluster.
+
+    linear_sum_ : ndarray
+        Linear sum of all the samples in a subcluster. Prevents holding
+        all sample data in memory.
+
+    squared_sum_ : float
+        Sum of the squared l2 norms of all samples belonging to a subcluster.
+
+    centroid_ : ndarray of shape (branching_factor + 1, n_features)
+        Centroid of the subcluster. Prevent recomputing of centroids when
+        ``CFNode.centroids_`` is called.
+
+    child_ : _CFNode
+        Child Node of the subcluster. Once a given _CFNode is set as the child
+        of the _CFNode, it is set to ``self.child_``.
+
+    sq_norm_ : ndarray of shape (branching_factor + 1,)
+        Squared norm of the subcluster. Used to prevent recomputing when
+        pairwise minimum distances are computed.
+    """
+
+    def __init__(self, *, linear_sum=None):
+        if linear_sum is None:
+            self.n_samples_ = 0
+            self.squared_sum_ = 0.0
+            self.centroid_ = self.linear_sum_ = 0
+        else:
+            self.n_samples_ = 1
+            self.centroid_ = self.linear_sum_ = linear_sum
+            self.squared_sum_ = self.sq_norm_ = np.dot(
+                self.linear_sum_, self.linear_sum_
+            )
+        self.child_ = None
+
+    def update(self, subcluster):
+        self.n_samples_ += subcluster.n_samples_
+        self.linear_sum_ += subcluster.linear_sum_
+        self.squared_sum_ += subcluster.squared_sum_
+        self.centroid_ = self.linear_sum_ / self.n_samples_
+        self.sq_norm_ = np.dot(self.centroid_, self.centroid_)
+
+    def merge_subcluster(self, nominee_cluster, threshold):
+        """Check if a cluster is worthy enough to be merged. If
+        yes then merge.
+        """
+        new_ss = self.squared_sum_ + nominee_cluster.squared_sum_
+        new_ls = self.linear_sum_ + nominee_cluster.linear_sum_
+        new_n = self.n_samples_ + nominee_cluster.n_samples_
+        new_centroid = (1 / new_n) * new_ls
+        new_sq_norm = np.dot(new_centroid, new_centroid)
+
+        # The squared radius of the cluster is defined:
+        #   r^2  = sum_i ||x_i - c||^2 / n
+        # with x_i the n points assigned to the cluster and c its centroid:
+        #   c = sum_i x_i / n
+        # This can be expanded to:
+        #   r^2 = sum_i ||x_i||^2 / n - 2 < sum_i x_i / n, c> + n ||c||^2 / n
+        # and therefore simplifies to:
+        #   r^2 = sum_i ||x_i||^2 / n - ||c||^2
+        sq_radius = new_ss / new_n - new_sq_norm
+
+        if sq_radius <= threshold**2:
+            (
+                self.n_samples_,
+                self.linear_sum_,
+                self.squared_sum_,
+                self.centroid_,
+                self.sq_norm_,
+            ) = (new_n, new_ls, new_ss, new_centroid, new_sq_norm)
+            return True
+        return False
+
+    @property
+    def radius(self):
+        """Return radius of the subcluster"""
+        # Because of numerical issues, this could become negative
+        sq_radius = self.squared_sum_ / self.n_samples_ - self.sq_norm_
+        return sqrt(max(0, sq_radius))
+
+
+class Birch(
+    ClassNamePrefixFeaturesOutMixin, ClusterMixin, TransformerMixin, BaseEstimator
+):
+    """Implements the BIRCH clustering algorithm.
+
+    It is a memory-efficient, online-learning algorithm provided as an
+    alternative to :class:`MiniBatchKMeans`. It constructs a tree
+    data structure with the cluster centroids being read off the leaf.
+    These can be either the final cluster centroids or can be provided as input
+    to another clustering algorithm such as :class:`AgglomerativeClustering`.
+
+    Read more in the :ref:`User Guide <birch>`.
+
+    .. versionadded:: 0.16
+
+    Parameters
+    ----------
+    threshold : float, default=0.5
+        The radius of the subcluster obtained by merging a new sample and the
+        closest subcluster should be lesser than the threshold. Otherwise a new
+        subcluster is started. Setting this value to be very low promotes
+        splitting and vice-versa.
+
+    branching_factor : int, default=50
+        Maximum number of CF subclusters in each node. If a new samples enters
+        such that the number of subclusters exceed the branching_factor then
+        that node is split into two nodes with the subclusters redistributed
+        in each. The parent subcluster of that node is removed and two new
+        subclusters are added as parents of the 2 split nodes.
+
+    n_clusters : int, instance of sklearn.cluster model or None, default=3
+        Number of clusters after the final clustering step, which treats the
+        subclusters from the leaves as new samples.
+
+        - `None` : the final clustering step is not performed and the
+          subclusters are returned as they are.
+
+        - :mod:`sklearn.cluster` Estimator : If a model is provided, the model
+          is fit treating the subclusters as new samples and the initial data
+          is mapped to the label of the closest subcluster.
+
+        - `int` : the model fit is :class:`AgglomerativeClustering` with
+          `n_clusters` set to be equal to the int.
+
+    compute_labels : bool, default=True
+        Whether or not to compute labels for each fit.
+
+    copy : bool, default=True
+        Whether or not to make a copy of the given data. If set to False,
+        the initial data will be overwritten.
+
+    Attributes
+    ----------
+    root_ : _CFNode
+        Root of the CFTree.
+
+    dummy_leaf_ : _CFNode
+        Start pointer to all the leaves.
+
+    subcluster_centers_ : ndarray
+        Centroids of all subclusters read directly from the leaves.
+
+    subcluster_labels_ : ndarray
+        Labels assigned to the centroids of the subclusters after
+        they are clustered globally.
+
+    labels_ : ndarray of shape (n_samples,)
+        Array of labels assigned to the input data.
+        if partial_fit is used instead of fit, they are assigned to the
+        last batch of data.
+
+    n_features_in_ : int
+        Number of features seen during :term:`fit`.
+
+        .. versionadded:: 0.24
+
+    feature_names_in_ : ndarray of shape (`n_features_in_`,)
+        Names of features seen during :term:`fit`. Defined only when `X`
+        has feature names that are all strings.
+
+        .. versionadded:: 1.0
+
+    See Also
+    --------
+    MiniBatchKMeans : Alternative implementation that does incremental updates
+        of the centers' positions using mini-batches.
+
+    Notes
+    -----
+    The tree data structure consists of nodes with each node consisting of
+    a number of subclusters. The maximum number of subclusters in a node
+    is determined by the branching factor. Each subcluster maintains a
+    linear sum, squared sum and the number of samples in that subcluster.
+    In addition, each subcluster can also have a node as its child, if the
+    subcluster is not a member of a leaf node.
+
+    For a new point entering the root, it is merged with the subcluster closest
+    to it and the linear sum, squared sum and the number of samples of that
+    subcluster are updated. This is done recursively till the properties of
+    the leaf node are updated.
+
+    References
+    ----------
+    * Tian Zhang, Raghu Ramakrishnan, Maron Livny
+      BIRCH: An efficient data clustering method for large databases.
+      https://www.cs.sfu.ca/CourseCentral/459/han/papers/zhang96.pdf
+
+    * Roberto Perdisci
+      JBirch - Java implementation of BIRCH clustering algorithm
+      https://code.google.com/archive/p/jbirch
+
+    Examples
+    --------
+    >>> from sklearn.cluster import Birch
+    >>> X = [[0, 1], [0.3, 1], [-0.3, 1], [0, -1], [0.3, -1], [-0.3, -1]]
+    >>> brc = Birch(n_clusters=None)
+    >>> brc.fit(X)
+    Birch(n_clusters=None)
+    >>> brc.predict(X)
+    array([0, 0, 0, 1, 1, 1])
+    """
+
+    _parameter_constraints: dict = {
+        "threshold": [Interval(Real, 0.0, None, closed="neither")],
+        "branching_factor": [Interval(Integral, 1, None, closed="neither")],
+        "n_clusters": [None, ClusterMixin, Interval(Integral, 1, None, closed="left")],
+        "compute_labels": ["boolean"],
+        "copy": ["boolean"],
+    }
+
+    def __init__(
+        self,
+        *,
+        threshold=0.5,
+        branching_factor=50,
+        n_clusters=3,
+        compute_labels=True,
+        copy=True,
+    ):
+        self.threshold = threshold
+        self.branching_factor = branching_factor
+        self.n_clusters = n_clusters
+        self.compute_labels = compute_labels
+        self.copy = copy
+
+    @_fit_context(prefer_skip_nested_validation=True)
+    def fit(self, X, y=None):
+        """
+        Build a CF Tree for the input data.
+
+        Parameters
+        ----------
+        X : {array-like, sparse matrix} of shape (n_samples, n_features)
+            Input data.
+
+        y : Ignored
+            Not used, present here for API consistency by convention.
+
+        Returns
+        -------
+        self
+            Fitted estimator.
+        """
+        return self._fit(X, partial=False)
+
+    def _fit(self, X, partial):
+        has_root = getattr(self, "root_", None)
+        first_call = not (partial and has_root)
+
+        X = self._validate_data(
+            X,
+            accept_sparse="csr",
+            copy=self.copy,
+            reset=first_call,
+            dtype=[np.float64, np.float32],
+        )
+        threshold = self.threshold
+        branching_factor = self.branching_factor
+
+        n_samples, n_features = X.shape
+
+        # If partial_fit is called for the first time or fit is called, we
+        # start a new tree.
+        if first_call:
+            # The first root is the leaf. Manipulate this object throughout.
+            self.root_ = _CFNode(
+                threshold=threshold,
+                branching_factor=branching_factor,
+                is_leaf=True,
+                n_features=n_features,
+                dtype=X.dtype,
+            )
+
+            # To enable getting back subclusters.
+            self.dummy_leaf_ = _CFNode(
+                threshold=threshold,
+                branching_factor=branching_factor,
+                is_leaf=True,
+                n_features=n_features,
+                dtype=X.dtype,
+            )
+            self.dummy_leaf_.next_leaf_ = self.root_
+            self.root_.prev_leaf_ = self.dummy_leaf_
+
+        # Cannot vectorize. Enough to convince to use cython.
+        if not sparse.issparse(X):
+            iter_func = iter
+        else:
+            iter_func = _iterate_sparse_X
+
+        for sample in iter_func(X):
+            subcluster = _CFSubcluster(linear_sum=sample)
+            split = self.root_.insert_cf_subcluster(subcluster)
+
+            if split:
+                new_subcluster1, new_subcluster2 = _split_node(
+                    self.root_, threshold, branching_factor
+                )
+                del self.root_
+                self.root_ = _CFNode(
+                    threshold=threshold,
+                    branching_factor=branching_factor,
+                    is_leaf=False,
+                    n_features=n_features,
+                    dtype=X.dtype,
+                )
+                self.root_.append_subcluster(new_subcluster1)
+                self.root_.append_subcluster(new_subcluster2)
+
+        centroids = np.concatenate([leaf.centroids_ for leaf in self._get_leaves()])
+        self.subcluster_centers_ = centroids
+        self._n_features_out = self.subcluster_centers_.shape[0]
+
+        self._global_clustering(X)
+        return self
+
+    def _get_leaves(self):
+        """
+        Retrieve the leaves of the CF Node.
+
+        Returns
+        -------
+        leaves : list of shape (n_leaves,)
+            List of the leaf nodes.
+        """
+        leaf_ptr = self.dummy_leaf_.next_leaf_
+        leaves = []
+        while leaf_ptr is not None:
+            leaves.append(leaf_ptr)
+            leaf_ptr = leaf_ptr.next_leaf_
+        return leaves
+
+    @_fit_context(prefer_skip_nested_validation=True)
+    def partial_fit(self, X=None, y=None):
+        """
+        Online learning. Prevents rebuilding of CFTree from scratch.
+
+        Parameters
+        ----------
+        X : {array-like, sparse matrix} of shape (n_samples, n_features), \
+            default=None
+            Input data. If X is not provided, only the global clustering
+            step is done.
+
+        y : Ignored
+            Not used, present here for API consistency by convention.
+
+        Returns
+        -------
+        self
+            Fitted estimator.
+        """
+        if X is None:
+            # Perform just the final global clustering step.
+            self._global_clustering()
+            return self
+        else:
+            return self._fit(X, partial=True)
+
+    def _check_fit(self, X):
+        check_is_fitted(self)
+
+        if (
+            hasattr(self, "subcluster_centers_")
+            and X.shape[1] != self.subcluster_centers_.shape[1]
+        ):
+            raise ValueError(
+                "Training data and predicted data do not have same number of features."
+            )
+
+    def predict(self, X):
+        """
+        Predict data using the ``centroids_`` of subclusters.
+
+        Avoid computation of the row norms of X.
+
+        Parameters
+        ----------
+        X : {array-like, sparse matrix} of shape (n_samples, n_features)
+            Input data.
+
+        Returns
+        -------
+        labels : ndarray of shape(n_samples,)
+            Labelled data.
+        """
+        check_is_fitted(self)
+        X = self._validate_data(X, accept_sparse="csr", reset=False)
+        return self._predict(X)
+
+    def _predict(self, X):
+        """Predict data using the ``centroids_`` of subclusters."""
+        kwargs = {"Y_norm_squared": self._subcluster_norms}
+
+        with config_context(assume_finite=True):
+            argmin = pairwise_distances_argmin(
+                X, self.subcluster_centers_, metric_kwargs=kwargs
+            )
+        return self.subcluster_labels_[argmin]
+
+    def transform(self, X):
+        """
+        Transform X into subcluster centroids dimension.
+
+        Each dimension represents the distance from the sample point to each
+        cluster centroid.
+
+        Parameters
+        ----------
+        X : {array-like, sparse matrix} of shape (n_samples, n_features)
+            Input data.
+
+        Returns
+        -------
+        X_trans : {array-like, sparse matrix} of shape (n_samples, n_clusters)
+            Transformed data.
+        """
+        check_is_fitted(self)
+        X = self._validate_data(X, accept_sparse="csr", reset=False)
+        with config_context(assume_finite=True):
+            return euclidean_distances(X, self.subcluster_centers_)
+
+    def _global_clustering(self, X=None):
+        """
+        Global clustering for the subclusters obtained after fitting
+        """
+        clusterer = self.n_clusters
+        centroids = self.subcluster_centers_
+        compute_labels = (X is not None) and self.compute_labels
+
+        # Preprocessing for the global clustering.
+        not_enough_centroids = False
+        if isinstance(clusterer, Integral):
+            clusterer = AgglomerativeClustering(n_clusters=self.n_clusters)
+            # There is no need to perform the global clustering step.
+            if len(centroids) < self.n_clusters:
+                not_enough_centroids = True
+
+        # To use in predict to avoid recalculation.
+        self._subcluster_norms = row_norms(self.subcluster_centers_, squared=True)
+
+        if clusterer is None or not_enough_centroids:
+            self.subcluster_labels_ = np.arange(len(centroids))
+            if not_enough_centroids:
+                warnings.warn(
+                    "Number of subclusters found (%d) by BIRCH is less "
+                    "than (%d). Decrease the threshold."
+                    % (len(centroids), self.n_clusters),
+                    ConvergenceWarning,
+                )
+        else:
+            # The global clustering step that clusters the subclusters of
+            # the leaves. It assumes the centroids of the subclusters as
+            # samples and finds the final centroids.
+            self.subcluster_labels_ = clusterer.fit_predict(self.subcluster_centers_)
+
+        if compute_labels:
+            self.labels_ = self._predict(X)
+
+    def _more_tags(self):
+        return {"preserves_dtype": [np.float64, np.float32]}