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"""
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The :mod:`sklearn.cluster` module gathers popular unsupervised clustering
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algorithms.
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"""
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from ._spectral import spectral_clustering, SpectralClustering
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from ._mean_shift import mean_shift, MeanShift, estimate_bandwidth, get_bin_seeds
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from ._affinity_propagation import affinity_propagation, AffinityPropagation
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from ._agglomerative import (
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ward_tree,
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AgglomerativeClustering,
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linkage_tree,
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FeatureAgglomeration,
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)
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from ._kmeans import k_means, KMeans, MiniBatchKMeans, kmeans_plusplus
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from ._bisect_k_means import BisectingKMeans
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from ._dbscan import dbscan, DBSCAN
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from ._optics import (
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OPTICS,
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cluster_optics_dbscan,
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compute_optics_graph,
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cluster_optics_xi,
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)
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from ._bicluster import SpectralBiclustering, SpectralCoclustering
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from ._birch import Birch
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__all__ = [
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"AffinityPropagation",
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"AgglomerativeClustering",
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"Birch",
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"DBSCAN",
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"OPTICS",
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"cluster_optics_dbscan",
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"cluster_optics_xi",
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"compute_optics_graph",
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"KMeans",
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"BisectingKMeans",
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"FeatureAgglomeration",
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"MeanShift",
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"MiniBatchKMeans",
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"SpectralClustering",
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"affinity_propagation",
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"dbscan",
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"estimate_bandwidth",
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"get_bin_seeds",
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"k_means",
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"kmeans_plusplus",
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"linkage_tree",
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"mean_shift",
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"spectral_clustering",
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"ward_tree",
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"SpectralBiclustering",
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"SpectralCoclustering",
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]
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"""Affinity Propagation clustering algorithm."""
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# Author: Alexandre Gramfort alexandre.gramfort@inria.fr
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# Gael Varoquaux gael.varoquaux@normalesup.org
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# License: BSD 3 clause
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import numbers
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import warnings
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import numpy as np
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from ..exceptions import ConvergenceWarning
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from ..base import BaseEstimator, ClusterMixin
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from ..utils import as_float_array, check_random_state
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from ..utils import check_scalar
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from ..utils.validation import check_is_fitted
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from ..metrics import euclidean_distances
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from ..metrics import pairwise_distances_argmin
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from .._config import config_context
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def _equal_similarities_and_preferences(S, preference):
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def all_equal_preferences():
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return np.all(preference == preference.flat[0])
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def all_equal_similarities():
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# Create mask to ignore diagonal of S
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mask = np.ones(S.shape, dtype=bool)
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np.fill_diagonal(mask, 0)
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return np.all(S[mask].flat == S[mask].flat[0])
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return all_equal_preferences() and all_equal_similarities()
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def affinity_propagation(
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S,
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*,
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preference=None,
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convergence_iter=15,
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max_iter=200,
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damping=0.5,
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copy=True,
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verbose=False,
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return_n_iter=False,
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random_state=None,
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):
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"""Perform Affinity Propagation Clustering of data.
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Read more in the :ref:`User Guide <affinity_propagation>`.
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Parameters
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----------
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S : array-like of shape (n_samples, n_samples)
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Matrix of similarities between points.
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preference : array-like of shape (n_samples,) or float, default=None
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Preferences for each point - points with larger values of
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preferences are more likely to be chosen as exemplars. The number of
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exemplars, i.e. of clusters, is influenced by the input preferences
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value. If the preferences are not passed as arguments, they will be
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set to the median of the input similarities (resulting in a moderate
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number of clusters). For a smaller amount of clusters, this can be set
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to the minimum value of the similarities.
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convergence_iter : int, default=15
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Number of iterations with no change in the number
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of estimated clusters that stops the convergence.
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max_iter : int, default=200
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Maximum number of iterations.
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damping : float, default=0.5
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Damping factor between 0.5 and 1.
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copy : bool, default=True
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If copy is False, the affinity matrix is modified inplace by the
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algorithm, for memory efficiency.
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verbose : bool, default=False
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The verbosity level.
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return_n_iter : bool, default=False
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Whether or not to return the number of iterations.
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random_state : int, RandomState instance or None, default=None
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Pseudo-random number generator to control the starting state.
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Use an int for reproducible results across function calls.
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See the :term:`Glossary <random_state>`.
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.. versionadded:: 0.23
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this parameter was previously hardcoded as 0.
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Returns
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-------
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cluster_centers_indices : ndarray of shape (n_clusters,)
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Index of clusters centers.
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labels : ndarray of shape (n_samples,)
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Cluster labels for each point.
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n_iter : int
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Number of iterations run. Returned only if `return_n_iter` is
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set to True.
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Notes
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-----
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For an example, see :ref:`examples/cluster/plot_affinity_propagation.py
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<sphx_glr_auto_examples_cluster_plot_affinity_propagation.py>`.
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When the algorithm does not converge, it will still return a arrays of
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``cluster_center_indices`` and labels if there are any exemplars/clusters,
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however they may be degenerate and should be used with caution.
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When all training samples have equal similarities and equal preferences,
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the assignment of cluster centers and labels depends on the preference.
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If the preference is smaller than the similarities, a single cluster center
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and label ``0`` for every sample will be returned. Otherwise, every
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training sample becomes its own cluster center and is assigned a unique
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label.
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References
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----------
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Brendan J. Frey and Delbert Dueck, "Clustering by Passing Messages
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Between Data Points", Science Feb. 2007
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"""
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S = as_float_array(S, copy=copy)
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n_samples = S.shape[0]
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if S.shape[0] != S.shape[1]:
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raise ValueError("S must be a square array (shape=%s)" % repr(S.shape))
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if preference is None:
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preference = np.median(S)
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preference = np.array(preference)
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if n_samples == 1 or _equal_similarities_and_preferences(S, preference):
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# It makes no sense to run the algorithm in this case, so return 1 or
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# n_samples clusters, depending on preferences
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warnings.warn(
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"All samples have mutually equal similarities. "
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"Returning arbitrary cluster center(s)."
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)
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if preference.flat[0] >= S.flat[n_samples - 1]:
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return (
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(np.arange(n_samples), np.arange(n_samples), 0)
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if return_n_iter
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else (np.arange(n_samples), np.arange(n_samples))
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)
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else:
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return (
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(np.array([0]), np.array([0] * n_samples), 0)
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if return_n_iter
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else (np.array([0]), np.array([0] * n_samples))
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)
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random_state = check_random_state(random_state)
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# Place preference on the diagonal of S
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S.flat[:: (n_samples + 1)] = preference
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A = np.zeros((n_samples, n_samples))
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R = np.zeros((n_samples, n_samples)) # Initialize messages
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# Intermediate results
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tmp = np.zeros((n_samples, n_samples))
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# Remove degeneracies
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S += (
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np.finfo(S.dtype).eps * S + np.finfo(S.dtype).tiny * 100
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) * random_state.standard_normal(size=(n_samples, n_samples))
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# Execute parallel affinity propagation updates
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e = np.zeros((n_samples, convergence_iter))
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ind = np.arange(n_samples)
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for it in range(max_iter):
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# tmp = A + S; compute responsibilities
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np.add(A, S, tmp)
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I = np.argmax(tmp, axis=1)
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Y = tmp[ind, I] # np.max(A + S, axis=1)
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tmp[ind, I] = -np.inf
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Y2 = np.max(tmp, axis=1)
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# tmp = Rnew
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np.subtract(S, Y[:, None], tmp)
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tmp[ind, I] = S[ind, I] - Y2
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# Damping
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tmp *= 1 - damping
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R *= damping
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R += tmp
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# tmp = Rp; compute availabilities
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np.maximum(R, 0, tmp)
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tmp.flat[:: n_samples + 1] = R.flat[:: n_samples + 1]
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# tmp = -Anew
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tmp -= np.sum(tmp, axis=0)
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dA = np.diag(tmp).copy()
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tmp.clip(0, np.inf, tmp)
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tmp.flat[:: n_samples + 1] = dA
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# Damping
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tmp *= 1 - damping
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A *= damping
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A -= tmp
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# Check for convergence
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E = (np.diag(A) + np.diag(R)) > 0
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e[:, it % convergence_iter] = E
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K = np.sum(E, axis=0)
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if it >= convergence_iter:
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se = np.sum(e, axis=1)
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unconverged = np.sum((se == convergence_iter) + (se == 0)) != n_samples
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if (not unconverged and (K > 0)) or (it == max_iter):
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never_converged = False
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if verbose:
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print("Converged after %d iterations." % it)
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break
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else:
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never_converged = True
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if verbose:
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print("Did not converge")
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I = np.flatnonzero(E)
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K = I.size # Identify exemplars
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if K > 0:
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if never_converged:
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warnings.warn(
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"Affinity propagation did not converge, this model "
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"may return degenerate cluster centers and labels.",
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ConvergenceWarning,
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)
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c = np.argmax(S[:, I], axis=1)
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c[I] = np.arange(K) # Identify clusters
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# Refine the final set of exemplars and clusters and return results
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for k in range(K):
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ii = np.where(c == k)[0]
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j = np.argmax(np.sum(S[ii[:, np.newaxis], ii], axis=0))
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I[k] = ii[j]
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c = np.argmax(S[:, I], axis=1)
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c[I] = np.arange(K)
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labels = I[c]
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# Reduce labels to a sorted, gapless, list
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cluster_centers_indices = np.unique(labels)
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labels = np.searchsorted(cluster_centers_indices, labels)
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else:
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warnings.warn(
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"Affinity propagation did not converge and this model "
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"will not have any cluster centers.",
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ConvergenceWarning,
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)
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labels = np.array([-1] * n_samples)
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cluster_centers_indices = []
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if return_n_iter:
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return cluster_centers_indices, labels, it + 1
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else:
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return cluster_centers_indices, labels
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###############################################################################
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class AffinityPropagation(ClusterMixin, BaseEstimator):
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"""Perform Affinity Propagation Clustering of data.
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Read more in the :ref:`User Guide <affinity_propagation>`.
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Parameters
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----------
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damping : float, default=0.5
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Damping factor in the range `[0.5, 1.0)` is the extent to
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which the current value is maintained relative to
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incoming values (weighted 1 - damping). This in order
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to avoid numerical oscillations when updating these
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values (messages).
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max_iter : int, default=200
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Maximum number of iterations.
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convergence_iter : int, default=15
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Number of iterations with no change in the number
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of estimated clusters that stops the convergence.
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copy : bool, default=True
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Make a copy of input data.
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preference : array-like of shape (n_samples,) or float, default=None
|
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Preferences for each point - points with larger values of
|
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preferences are more likely to be chosen as exemplars. The number
|
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of exemplars, ie of clusters, is influenced by the input
|
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preferences value. If the preferences are not passed as arguments,
|
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they will be set to the median of the input similarities.
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|
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affinity : {'euclidean', 'precomputed'}, default='euclidean'
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Which affinity to use. At the moment 'precomputed' and
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``euclidean`` are supported. 'euclidean' uses the
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negative squared euclidean distance between points.
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verbose : bool, default=False
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Whether to be verbose.
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random_state : int, RandomState instance or None, default=None
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Pseudo-random number generator to control the starting state.
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Use an int for reproducible results across function calls.
|
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See the :term:`Glossary <random_state>`.
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.. versionadded:: 0.23
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this parameter was previously hardcoded as 0.
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Attributes
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||||
----------
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cluster_centers_indices_ : ndarray of shape (n_clusters,)
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Indices of cluster centers.
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cluster_centers_ : ndarray of shape (n_clusters, n_features)
|
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Cluster centers (if affinity != ``precomputed``).
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labels_ : ndarray of shape (n_samples,)
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Labels of each point.
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affinity_matrix_ : ndarray of shape (n_samples, n_samples)
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Stores the affinity matrix used in ``fit``.
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n_iter_ : int
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Number of iterations taken to converge.
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n_features_in_ : int
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Number of features seen during :term:`fit`.
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.. versionadded:: 0.24
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feature_names_in_ : ndarray of shape (`n_features_in_`,)
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Names of features seen during :term:`fit`. Defined only when `X`
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has feature names that are all strings.
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.. versionadded:: 1.0
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See Also
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--------
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AgglomerativeClustering : Recursively merges the pair of
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clusters that minimally increases a given linkage distance.
|
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FeatureAgglomeration : Similar to AgglomerativeClustering,
|
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but recursively merges features instead of samples.
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KMeans : K-Means clustering.
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MiniBatchKMeans : Mini-Batch K-Means clustering.
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MeanShift : Mean shift clustering using a flat kernel.
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SpectralClustering : Apply clustering to a projection
|
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of the normalized Laplacian.
|
||||
|
||||
Notes
|
||||
-----
|
||||
For an example, see :ref:`examples/cluster/plot_affinity_propagation.py
|
||||
<sphx_glr_auto_examples_cluster_plot_affinity_propagation.py>`.
|
||||
|
||||
The algorithmic complexity of affinity propagation is quadratic
|
||||
in the number of points.
|
||||
|
||||
When the algorithm does not converge, it will still return a arrays of
|
||||
``cluster_center_indices`` and labels if there are any exemplars/clusters,
|
||||
however they may be degenerate and should be used with caution.
|
||||
|
||||
When ``fit`` does not converge, ``cluster_centers_`` is still populated
|
||||
however it may be degenerate. In such a case, proceed with caution.
|
||||
If ``fit`` does not converge and fails to produce any ``cluster_centers_``
|
||||
then ``predict`` will label every sample as ``-1``.
|
||||
|
||||
When all training samples have equal similarities and equal preferences,
|
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the assignment of cluster centers and labels depends on the preference.
|
||||
If the preference is smaller than the similarities, ``fit`` will result in
|
||||
a single cluster center and label ``0`` for every sample. Otherwise, every
|
||||
training sample becomes its own cluster center and is assigned a unique
|
||||
label.
|
||||
|
||||
References
|
||||
----------
|
||||
|
||||
Brendan J. Frey and Delbert Dueck, "Clustering by Passing Messages
|
||||
Between Data Points", Science Feb. 2007
|
||||
|
||||
Examples
|
||||
--------
|
||||
>>> from sklearn.cluster import AffinityPropagation
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>>> import numpy as np
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>>> X = np.array([[1, 2], [1, 4], [1, 0],
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... [4, 2], [4, 4], [4, 0]])
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>>> clustering = AffinityPropagation(random_state=5).fit(X)
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>>> clustering
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AffinityPropagation(random_state=5)
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>>> clustering.labels_
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||||
array([0, 0, 0, 1, 1, 1])
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>>> clustering.predict([[0, 0], [4, 4]])
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array([0, 1])
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>>> clustering.cluster_centers_
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||||
array([[1, 2],
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[4, 2]])
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||||
"""
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||||
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||||
def __init__(
|
||||
self,
|
||||
*,
|
||||
damping=0.5,
|
||||
max_iter=200,
|
||||
convergence_iter=15,
|
||||
copy=True,
|
||||
preference=None,
|
||||
affinity="euclidean",
|
||||
verbose=False,
|
||||
random_state=None,
|
||||
):
|
||||
|
||||
self.damping = damping
|
||||
self.max_iter = max_iter
|
||||
self.convergence_iter = convergence_iter
|
||||
self.copy = copy
|
||||
self.verbose = verbose
|
||||
self.preference = preference
|
||||
self.affinity = affinity
|
||||
self.random_state = random_state
|
||||
|
||||
def _more_tags(self):
|
||||
return {"pairwise": self.affinity == "precomputed"}
|
||||
|
||||
def fit(self, X, y=None):
|
||||
"""Fit the clustering from features, or affinity matrix.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
X : {array-like, sparse matrix} of shape (n_samples, n_features), or \
|
||||
array-like of shape (n_samples, n_samples)
|
||||
Training instances to cluster, or similarities / affinities between
|
||||
instances if ``affinity='precomputed'``. If a sparse feature matrix
|
||||
is provided, it will be converted into a sparse ``csr_matrix``.
|
||||
|
||||
y : Ignored
|
||||
Not used, present here for API consistency by convention.
|
||||
|
||||
Returns
|
||||
-------
|
||||
self
|
||||
Returns the instance itself.
|
||||
"""
|
||||
if self.affinity == "precomputed":
|
||||
accept_sparse = False
|
||||
else:
|
||||
accept_sparse = "csr"
|
||||
X = self._validate_data(X, accept_sparse=accept_sparse)
|
||||
if self.affinity == "precomputed":
|
||||
self.affinity_matrix_ = X
|
||||
elif self.affinity == "euclidean":
|
||||
self.affinity_matrix_ = -euclidean_distances(X, squared=True)
|
||||
else:
|
||||
raise ValueError(
|
||||
"Affinity must be 'precomputed' or 'euclidean'. Got %s instead"
|
||||
% str(self.affinity)
|
||||
)
|
||||
|
||||
check_scalar(
|
||||
self.damping,
|
||||
"damping",
|
||||
target_type=numbers.Real,
|
||||
min_val=0.5,
|
||||
max_val=1,
|
||||
include_boundaries="left",
|
||||
)
|
||||
check_scalar(self.max_iter, "max_iter", target_type=numbers.Integral, min_val=1)
|
||||
check_scalar(
|
||||
self.convergence_iter,
|
||||
"convergence_iter",
|
||||
target_type=numbers.Integral,
|
||||
min_val=1,
|
||||
)
|
||||
|
||||
(
|
||||
self.cluster_centers_indices_,
|
||||
self.labels_,
|
||||
self.n_iter_,
|
||||
) = affinity_propagation(
|
||||
self.affinity_matrix_,
|
||||
preference=self.preference,
|
||||
max_iter=self.max_iter,
|
||||
convergence_iter=self.convergence_iter,
|
||||
damping=self.damping,
|
||||
copy=self.copy,
|
||||
verbose=self.verbose,
|
||||
return_n_iter=True,
|
||||
random_state=self.random_state,
|
||||
)
|
||||
|
||||
if self.affinity != "precomputed":
|
||||
self.cluster_centers_ = X[self.cluster_centers_indices_].copy()
|
||||
|
||||
return self
|
||||
|
||||
def predict(self, X):
|
||||
"""Predict the closest cluster each sample in X belongs to.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
X : {array-like, sparse matrix} of shape (n_samples, n_features)
|
||||
New data to predict. If a sparse matrix is provided, it will be
|
||||
converted into a sparse ``csr_matrix``.
|
||||
|
||||
Returns
|
||||
-------
|
||||
labels : ndarray of shape (n_samples,)
|
||||
Cluster labels.
|
||||
"""
|
||||
check_is_fitted(self)
|
||||
X = self._validate_data(X, reset=False, accept_sparse="csr")
|
||||
if not hasattr(self, "cluster_centers_"):
|
||||
raise ValueError(
|
||||
"Predict method is not supported when affinity='precomputed'."
|
||||
)
|
||||
|
||||
if self.cluster_centers_.shape[0] > 0:
|
||||
with config_context(assume_finite=True):
|
||||
return pairwise_distances_argmin(X, self.cluster_centers_)
|
||||
else:
|
||||
warnings.warn(
|
||||
"This model does not have any cluster centers "
|
||||
"because affinity propagation did not converge. "
|
||||
"Labeling every sample as '-1'.",
|
||||
ConvergenceWarning,
|
||||
)
|
||||
return np.array([-1] * X.shape[0])
|
||||
|
||||
def fit_predict(self, X, y=None):
|
||||
"""Fit clustering from features/affinity matrix; return cluster labels.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
X : {array-like, sparse matrix} of shape (n_samples, n_features), or \
|
||||
array-like of shape (n_samples, n_samples)
|
||||
Training instances to cluster, or similarities / affinities between
|
||||
instances if ``affinity='precomputed'``. If a sparse feature matrix
|
||||
is provided, it will be converted into a sparse ``csr_matrix``.
|
||||
|
||||
y : Ignored
|
||||
Not used, present here for API consistency by convention.
|
||||
|
||||
Returns
|
||||
-------
|
||||
labels : ndarray of shape (n_samples,)
|
||||
Cluster labels.
|
||||
"""
|
||||
return super().fit_predict(X, y)
|
||||
File diff suppressed because it is too large
Load Diff
@@ -0,0 +1,627 @@
|
||||
"""Spectral biclustering algorithms."""
|
||||
# Authors : Kemal Eren
|
||||
# License: BSD 3 clause
|
||||
|
||||
from abc import ABCMeta, abstractmethod
|
||||
|
||||
import numpy as np
|
||||
import numbers
|
||||
|
||||
from scipy.linalg import norm
|
||||
from scipy.sparse import dia_matrix, issparse
|
||||
from scipy.sparse.linalg import eigsh, svds
|
||||
|
||||
from . import KMeans, MiniBatchKMeans
|
||||
from ..base import BaseEstimator, BiclusterMixin
|
||||
from ..utils import check_random_state
|
||||
from ..utils import check_scalar
|
||||
|
||||
from ..utils.extmath import make_nonnegative, randomized_svd, safe_sparse_dot
|
||||
|
||||
from ..utils.validation import assert_all_finite
|
||||
|
||||
|
||||
__all__ = ["SpectralCoclustering", "SpectralBiclustering"]
|
||||
|
||||
|
||||
def _scale_normalize(X):
|
||||
"""Normalize ``X`` by scaling rows and columns independently.
|
||||
|
||||
Returns the normalized matrix and the row and column scaling
|
||||
factors.
|
||||
"""
|
||||
X = make_nonnegative(X)
|
||||
row_diag = np.asarray(1.0 / np.sqrt(X.sum(axis=1))).squeeze()
|
||||
col_diag = np.asarray(1.0 / np.sqrt(X.sum(axis=0))).squeeze()
|
||||
row_diag = np.where(np.isnan(row_diag), 0, row_diag)
|
||||
col_diag = np.where(np.isnan(col_diag), 0, col_diag)
|
||||
if issparse(X):
|
||||
n_rows, n_cols = X.shape
|
||||
r = dia_matrix((row_diag, [0]), shape=(n_rows, n_rows))
|
||||
c = dia_matrix((col_diag, [0]), shape=(n_cols, n_cols))
|
||||
an = r * X * c
|
||||
else:
|
||||
an = row_diag[:, np.newaxis] * X * col_diag
|
||||
return an, row_diag, col_diag
|
||||
|
||||
|
||||
def _bistochastic_normalize(X, max_iter=1000, tol=1e-5):
|
||||
"""Normalize rows and columns of ``X`` simultaneously so that all
|
||||
rows sum to one constant and all columns sum to a different
|
||||
constant.
|
||||
"""
|
||||
# According to paper, this can also be done more efficiently with
|
||||
# deviation reduction and balancing algorithms.
|
||||
X = make_nonnegative(X)
|
||||
X_scaled = X
|
||||
for _ in range(max_iter):
|
||||
X_new, _, _ = _scale_normalize(X_scaled)
|
||||
if issparse(X):
|
||||
dist = norm(X_scaled.data - X.data)
|
||||
else:
|
||||
dist = norm(X_scaled - X_new)
|
||||
X_scaled = X_new
|
||||
if dist is not None and dist < tol:
|
||||
break
|
||||
return X_scaled
|
||||
|
||||
|
||||
def _log_normalize(X):
|
||||
"""Normalize ``X`` according to Kluger's log-interactions scheme."""
|
||||
X = make_nonnegative(X, min_value=1)
|
||||
if issparse(X):
|
||||
raise ValueError(
|
||||
"Cannot compute log of a sparse matrix,"
|
||||
" because log(x) diverges to -infinity as x"
|
||||
" goes to 0."
|
||||
)
|
||||
L = np.log(X)
|
||||
row_avg = L.mean(axis=1)[:, np.newaxis]
|
||||
col_avg = L.mean(axis=0)
|
||||
avg = L.mean()
|
||||
return L - row_avg - col_avg + avg
|
||||
|
||||
|
||||
class BaseSpectral(BiclusterMixin, BaseEstimator, metaclass=ABCMeta):
|
||||
"""Base class for spectral biclustering."""
|
||||
|
||||
@abstractmethod
|
||||
def __init__(
|
||||
self,
|
||||
n_clusters=3,
|
||||
svd_method="randomized",
|
||||
n_svd_vecs=None,
|
||||
mini_batch=False,
|
||||
init="k-means++",
|
||||
n_init=10,
|
||||
random_state=None,
|
||||
):
|
||||
self.n_clusters = n_clusters
|
||||
self.svd_method = svd_method
|
||||
self.n_svd_vecs = n_svd_vecs
|
||||
self.mini_batch = mini_batch
|
||||
self.init = init
|
||||
self.n_init = n_init
|
||||
self.random_state = random_state
|
||||
|
||||
def _check_parameters(self, n_samples):
|
||||
legal_svd_methods = ("randomized", "arpack")
|
||||
if self.svd_method not in legal_svd_methods:
|
||||
raise ValueError(
|
||||
"Unknown SVD method: '{0}'. svd_method must be one of {1}.".format(
|
||||
self.svd_method, legal_svd_methods
|
||||
)
|
||||
)
|
||||
check_scalar(self.n_init, "n_init", target_type=numbers.Integral, min_val=1)
|
||||
|
||||
def fit(self, X, y=None):
|
||||
"""Create a biclustering for X.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
X : array-like of shape (n_samples, n_features)
|
||||
Training data.
|
||||
|
||||
y : Ignored
|
||||
Not used, present for API consistency by convention.
|
||||
|
||||
Returns
|
||||
-------
|
||||
self : object
|
||||
SpectralBiclustering instance.
|
||||
"""
|
||||
X = self._validate_data(X, accept_sparse="csr", dtype=np.float64)
|
||||
self._check_parameters(X.shape[0])
|
||||
self._fit(X)
|
||||
return self
|
||||
|
||||
def _svd(self, array, n_components, n_discard):
|
||||
"""Returns first `n_components` left and right singular
|
||||
vectors u and v, discarding the first `n_discard`.
|
||||
"""
|
||||
if self.svd_method == "randomized":
|
||||
kwargs = {}
|
||||
if self.n_svd_vecs is not None:
|
||||
kwargs["n_oversamples"] = self.n_svd_vecs
|
||||
u, _, vt = randomized_svd(
|
||||
array, n_components, random_state=self.random_state, **kwargs
|
||||
)
|
||||
|
||||
elif self.svd_method == "arpack":
|
||||
u, _, vt = svds(array, k=n_components, ncv=self.n_svd_vecs)
|
||||
if np.any(np.isnan(vt)):
|
||||
# some eigenvalues of A * A.T are negative, causing
|
||||
# sqrt() to be np.nan. This causes some vectors in vt
|
||||
# to be np.nan.
|
||||
A = safe_sparse_dot(array.T, array)
|
||||
random_state = check_random_state(self.random_state)
|
||||
# initialize with [-1,1] as in ARPACK
|
||||
v0 = random_state.uniform(-1, 1, A.shape[0])
|
||||
_, v = eigsh(A, ncv=self.n_svd_vecs, v0=v0)
|
||||
vt = v.T
|
||||
if np.any(np.isnan(u)):
|
||||
A = safe_sparse_dot(array, array.T)
|
||||
random_state = check_random_state(self.random_state)
|
||||
# initialize with [-1,1] as in ARPACK
|
||||
v0 = random_state.uniform(-1, 1, A.shape[0])
|
||||
_, u = eigsh(A, ncv=self.n_svd_vecs, v0=v0)
|
||||
|
||||
assert_all_finite(u)
|
||||
assert_all_finite(vt)
|
||||
u = u[:, n_discard:]
|
||||
vt = vt[n_discard:]
|
||||
return u, vt.T
|
||||
|
||||
def _k_means(self, data, n_clusters):
|
||||
if self.mini_batch:
|
||||
model = MiniBatchKMeans(
|
||||
n_clusters,
|
||||
init=self.init,
|
||||
n_init=self.n_init,
|
||||
random_state=self.random_state,
|
||||
)
|
||||
else:
|
||||
model = KMeans(
|
||||
n_clusters,
|
||||
init=self.init,
|
||||
n_init=self.n_init,
|
||||
random_state=self.random_state,
|
||||
)
|
||||
model.fit(data)
|
||||
centroid = model.cluster_centers_
|
||||
labels = model.labels_
|
||||
return centroid, labels
|
||||
|
||||
def _more_tags(self):
|
||||
return {
|
||||
"_xfail_checks": {
|
||||
"check_estimators_dtypes": "raises nan error",
|
||||
"check_fit2d_1sample": "_scale_normalize fails",
|
||||
"check_fit2d_1feature": "raises apply_along_axis error",
|
||||
"check_estimator_sparse_data": "does not fail gracefully",
|
||||
"check_methods_subset_invariance": "empty array passed inside",
|
||||
"check_dont_overwrite_parameters": "empty array passed inside",
|
||||
"check_fit2d_predict1d": "empty array passed inside",
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
class SpectralCoclustering(BaseSpectral):
|
||||
"""Spectral Co-Clustering algorithm (Dhillon, 2001).
|
||||
|
||||
Clusters rows and columns of an array `X` to solve the relaxed
|
||||
normalized cut of the bipartite graph created from `X` as follows:
|
||||
the edge between row vertex `i` and column vertex `j` has weight
|
||||
`X[i, j]`.
|
||||
|
||||
The resulting bicluster structure is block-diagonal, since each
|
||||
row and each column belongs to exactly one bicluster.
|
||||
|
||||
Supports sparse matrices, as long as they are nonnegative.
|
||||
|
||||
Read more in the :ref:`User Guide <spectral_coclustering>`.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
n_clusters : int, default=3
|
||||
The number of biclusters to find.
|
||||
|
||||
svd_method : {'randomized', 'arpack'}, default='randomized'
|
||||
Selects the algorithm for finding singular vectors. May be
|
||||
'randomized' or 'arpack'. If 'randomized', use
|
||||
:func:`sklearn.utils.extmath.randomized_svd`, which may be faster
|
||||
for large matrices. If 'arpack', use
|
||||
:func:`scipy.sparse.linalg.svds`, which is more accurate, but
|
||||
possibly slower in some cases.
|
||||
|
||||
n_svd_vecs : int, default=None
|
||||
Number of vectors to use in calculating the SVD. Corresponds
|
||||
to `ncv` when `svd_method=arpack` and `n_oversamples` when
|
||||
`svd_method` is 'randomized`.
|
||||
|
||||
mini_batch : bool, default=False
|
||||
Whether to use mini-batch k-means, which is faster but may get
|
||||
different results.
|
||||
|
||||
init : {'k-means++', 'random', or ndarray of shape \
|
||||
(n_clusters, n_features), default='k-means++'
|
||||
Method for initialization of k-means algorithm; defaults to
|
||||
'k-means++'.
|
||||
|
||||
n_init : int, default=10
|
||||
Number of random initializations that are tried with the
|
||||
k-means algorithm.
|
||||
|
||||
If mini-batch k-means is used, the best initialization is
|
||||
chosen and the algorithm runs once. Otherwise, the algorithm
|
||||
is run for each initialization and the best solution chosen.
|
||||
|
||||
random_state : int, RandomState instance, default=None
|
||||
Used for randomizing the singular value decomposition and the k-means
|
||||
initialization. Use an int to make the randomness deterministic.
|
||||
See :term:`Glossary <random_state>`.
|
||||
|
||||
Attributes
|
||||
----------
|
||||
rows_ : array-like of shape (n_row_clusters, n_rows)
|
||||
Results of the clustering. `rows[i, r]` is True if
|
||||
cluster `i` contains row `r`. Available only after calling ``fit``.
|
||||
|
||||
columns_ : array-like of shape (n_column_clusters, n_columns)
|
||||
Results of the clustering, like `rows`.
|
||||
|
||||
row_labels_ : array-like of shape (n_rows,)
|
||||
The bicluster label of each row.
|
||||
|
||||
column_labels_ : array-like of shape (n_cols,)
|
||||
The bicluster label of each column.
|
||||
|
||||
biclusters_ : tuple of two ndarrays
|
||||
The tuple contains the `rows_` and `columns_` arrays.
|
||||
|
||||
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
|
||||
--------
|
||||
SpectralBiclustering : Partitions rows and columns under the assumption
|
||||
that the data has an underlying checkerboard structure.
|
||||
|
||||
References
|
||||
----------
|
||||
* :doi:`Dhillon, Inderjit S, 2001. Co-clustering documents and words using
|
||||
bipartite spectral graph partitioning.
|
||||
<10.1145/502512.502550>`
|
||||
|
||||
Examples
|
||||
--------
|
||||
>>> from sklearn.cluster import SpectralCoclustering
|
||||
>>> import numpy as np
|
||||
>>> X = np.array([[1, 1], [2, 1], [1, 0],
|
||||
... [4, 7], [3, 5], [3, 6]])
|
||||
>>> clustering = SpectralCoclustering(n_clusters=2, random_state=0).fit(X)
|
||||
>>> clustering.row_labels_ #doctest: +SKIP
|
||||
array([0, 1, 1, 0, 0, 0], dtype=int32)
|
||||
>>> clustering.column_labels_ #doctest: +SKIP
|
||||
array([0, 0], dtype=int32)
|
||||
>>> clustering
|
||||
SpectralCoclustering(n_clusters=2, random_state=0)
|
||||
"""
|
||||
|
||||
def __init__(
|
||||
self,
|
||||
n_clusters=3,
|
||||
*,
|
||||
svd_method="randomized",
|
||||
n_svd_vecs=None,
|
||||
mini_batch=False,
|
||||
init="k-means++",
|
||||
n_init=10,
|
||||
random_state=None,
|
||||
):
|
||||
super().__init__(
|
||||
n_clusters, svd_method, n_svd_vecs, mini_batch, init, n_init, random_state
|
||||
)
|
||||
|
||||
def _check_parameters(self, n_samples):
|
||||
super()._check_parameters(n_samples)
|
||||
check_scalar(
|
||||
self.n_clusters,
|
||||
"n_clusters",
|
||||
target_type=numbers.Integral,
|
||||
min_val=1,
|
||||
max_val=n_samples,
|
||||
)
|
||||
|
||||
def _fit(self, X):
|
||||
normalized_data, row_diag, col_diag = _scale_normalize(X)
|
||||
n_sv = 1 + int(np.ceil(np.log2(self.n_clusters)))
|
||||
u, v = self._svd(normalized_data, n_sv, n_discard=1)
|
||||
z = np.vstack((row_diag[:, np.newaxis] * u, col_diag[:, np.newaxis] * v))
|
||||
|
||||
_, labels = self._k_means(z, self.n_clusters)
|
||||
|
||||
n_rows = X.shape[0]
|
||||
self.row_labels_ = labels[:n_rows]
|
||||
self.column_labels_ = labels[n_rows:]
|
||||
|
||||
self.rows_ = np.vstack([self.row_labels_ == c for c in range(self.n_clusters)])
|
||||
self.columns_ = np.vstack(
|
||||
[self.column_labels_ == c for c in range(self.n_clusters)]
|
||||
)
|
||||
|
||||
|
||||
class SpectralBiclustering(BaseSpectral):
|
||||
"""Spectral biclustering (Kluger, 2003).
|
||||
|
||||
Partitions rows and columns under the assumption that the data has
|
||||
an underlying checkerboard structure. For instance, if there are
|
||||
two row partitions and three column partitions, each row will
|
||||
belong to three biclusters, and each column will belong to two
|
||||
biclusters. The outer product of the corresponding row and column
|
||||
label vectors gives this checkerboard structure.
|
||||
|
||||
Read more in the :ref:`User Guide <spectral_biclustering>`.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
n_clusters : int or tuple (n_row_clusters, n_column_clusters), default=3
|
||||
The number of row and column clusters in the checkerboard
|
||||
structure.
|
||||
|
||||
method : {'bistochastic', 'scale', 'log'}, default='bistochastic'
|
||||
Method of normalizing and converting singular vectors into
|
||||
biclusters. May be one of 'scale', 'bistochastic', or 'log'.
|
||||
The authors recommend using 'log'. If the data is sparse,
|
||||
however, log normalization will not work, which is why the
|
||||
default is 'bistochastic'.
|
||||
|
||||
.. warning::
|
||||
if `method='log'`, the data must be sparse.
|
||||
|
||||
n_components : int, default=6
|
||||
Number of singular vectors to check.
|
||||
|
||||
n_best : int, default=3
|
||||
Number of best singular vectors to which to project the data
|
||||
for clustering.
|
||||
|
||||
svd_method : {'randomized', 'arpack'}, default='randomized'
|
||||
Selects the algorithm for finding singular vectors. May be
|
||||
'randomized' or 'arpack'. If 'randomized', uses
|
||||
:func:`~sklearn.utils.extmath.randomized_svd`, which may be faster
|
||||
for large matrices. If 'arpack', uses
|
||||
`scipy.sparse.linalg.svds`, which is more accurate, but
|
||||
possibly slower in some cases.
|
||||
|
||||
n_svd_vecs : int, default=None
|
||||
Number of vectors to use in calculating the SVD. Corresponds
|
||||
to `ncv` when `svd_method=arpack` and `n_oversamples` when
|
||||
`svd_method` is 'randomized`.
|
||||
|
||||
mini_batch : bool, default=False
|
||||
Whether to use mini-batch k-means, which is faster but may get
|
||||
different results.
|
||||
|
||||
init : {'k-means++', 'random'} or ndarray of (n_clusters, n_features), \
|
||||
default='k-means++'
|
||||
Method for initialization of k-means algorithm; defaults to
|
||||
'k-means++'.
|
||||
|
||||
n_init : int, default=10
|
||||
Number of random initializations that are tried with the
|
||||
k-means algorithm.
|
||||
|
||||
If mini-batch k-means is used, the best initialization is
|
||||
chosen and the algorithm runs once. Otherwise, the algorithm
|
||||
is run for each initialization and the best solution chosen.
|
||||
|
||||
random_state : int, RandomState instance, default=None
|
||||
Used for randomizing the singular value decomposition and the k-means
|
||||
initialization. Use an int to make the randomness deterministic.
|
||||
See :term:`Glossary <random_state>`.
|
||||
|
||||
Attributes
|
||||
----------
|
||||
rows_ : array-like of shape (n_row_clusters, n_rows)
|
||||
Results of the clustering. `rows[i, r]` is True if
|
||||
cluster `i` contains row `r`. Available only after calling ``fit``.
|
||||
|
||||
columns_ : array-like of shape (n_column_clusters, n_columns)
|
||||
Results of the clustering, like `rows`.
|
||||
|
||||
row_labels_ : array-like of shape (n_rows,)
|
||||
Row partition labels.
|
||||
|
||||
column_labels_ : array-like of shape (n_cols,)
|
||||
Column partition labels.
|
||||
|
||||
biclusters_ : tuple of two ndarrays
|
||||
The tuple contains the `rows_` and `columns_` arrays.
|
||||
|
||||
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
|
||||
--------
|
||||
SpectralCoclustering : Spectral Co-Clustering algorithm (Dhillon, 2001).
|
||||
|
||||
References
|
||||
----------
|
||||
|
||||
* :doi:`Kluger, Yuval, et. al., 2003. Spectral biclustering of microarray
|
||||
data: coclustering genes and conditions.
|
||||
<10.1101/gr.648603>`
|
||||
|
||||
Examples
|
||||
--------
|
||||
>>> from sklearn.cluster import SpectralBiclustering
|
||||
>>> import numpy as np
|
||||
>>> X = np.array([[1, 1], [2, 1], [1, 0],
|
||||
... [4, 7], [3, 5], [3, 6]])
|
||||
>>> clustering = SpectralBiclustering(n_clusters=2, random_state=0).fit(X)
|
||||
>>> clustering.row_labels_
|
||||
array([1, 1, 1, 0, 0, 0], dtype=int32)
|
||||
>>> clustering.column_labels_
|
||||
array([0, 1], dtype=int32)
|
||||
>>> clustering
|
||||
SpectralBiclustering(n_clusters=2, random_state=0)
|
||||
"""
|
||||
|
||||
def __init__(
|
||||
self,
|
||||
n_clusters=3,
|
||||
*,
|
||||
method="bistochastic",
|
||||
n_components=6,
|
||||
n_best=3,
|
||||
svd_method="randomized",
|
||||
n_svd_vecs=None,
|
||||
mini_batch=False,
|
||||
init="k-means++",
|
||||
n_init=10,
|
||||
random_state=None,
|
||||
):
|
||||
super().__init__(
|
||||
n_clusters, svd_method, n_svd_vecs, mini_batch, init, n_init, random_state
|
||||
)
|
||||
self.method = method
|
||||
self.n_components = n_components
|
||||
self.n_best = n_best
|
||||
|
||||
def _check_parameters(self, n_samples):
|
||||
super()._check_parameters(n_samples)
|
||||
legal_methods = ("bistochastic", "scale", "log")
|
||||
if self.method not in legal_methods:
|
||||
raise ValueError(
|
||||
"Unknown method: '{0}'. method must be one of {1}.".format(
|
||||
self.method, legal_methods
|
||||
)
|
||||
)
|
||||
try:
|
||||
check_scalar(
|
||||
self.n_clusters,
|
||||
"n_clusters",
|
||||
target_type=numbers.Integral,
|
||||
min_val=1,
|
||||
max_val=n_samples,
|
||||
)
|
||||
except (ValueError, TypeError):
|
||||
try:
|
||||
n_row_clusters, n_column_clusters = self.n_clusters
|
||||
check_scalar(
|
||||
n_row_clusters,
|
||||
"n_row_clusters",
|
||||
target_type=numbers.Integral,
|
||||
min_val=1,
|
||||
max_val=n_samples,
|
||||
)
|
||||
check_scalar(
|
||||
n_column_clusters,
|
||||
"n_column_clusters",
|
||||
target_type=numbers.Integral,
|
||||
min_val=1,
|
||||
max_val=n_samples,
|
||||
)
|
||||
except (ValueError, TypeError) as e:
|
||||
raise ValueError(
|
||||
"Incorrect parameter n_clusters has value:"
|
||||
f" {self.n_clusters}. It should either be a single integer"
|
||||
" or an iterable with two integers:"
|
||||
" (n_row_clusters, n_column_clusters)"
|
||||
" And the values are should be in the"
|
||||
" range: (1, n_samples)"
|
||||
) from e
|
||||
check_scalar(
|
||||
self.n_components, "n_components", target_type=numbers.Integral, min_val=1
|
||||
)
|
||||
check_scalar(
|
||||
self.n_best,
|
||||
"n_best",
|
||||
target_type=numbers.Integral,
|
||||
min_val=1,
|
||||
max_val=self.n_components,
|
||||
)
|
||||
|
||||
def _fit(self, X):
|
||||
n_sv = self.n_components
|
||||
if self.method == "bistochastic":
|
||||
normalized_data = _bistochastic_normalize(X)
|
||||
n_sv += 1
|
||||
elif self.method == "scale":
|
||||
normalized_data, _, _ = _scale_normalize(X)
|
||||
n_sv += 1
|
||||
elif self.method == "log":
|
||||
normalized_data = _log_normalize(X)
|
||||
n_discard = 0 if self.method == "log" else 1
|
||||
u, v = self._svd(normalized_data, n_sv, n_discard)
|
||||
ut = u.T
|
||||
vt = v.T
|
||||
|
||||
try:
|
||||
n_row_clusters, n_col_clusters = self.n_clusters
|
||||
except TypeError:
|
||||
n_row_clusters = n_col_clusters = self.n_clusters
|
||||
|
||||
best_ut = self._fit_best_piecewise(ut, self.n_best, n_row_clusters)
|
||||
|
||||
best_vt = self._fit_best_piecewise(vt, self.n_best, n_col_clusters)
|
||||
|
||||
self.row_labels_ = self._project_and_cluster(X, best_vt.T, n_row_clusters)
|
||||
|
||||
self.column_labels_ = self._project_and_cluster(X.T, best_ut.T, n_col_clusters)
|
||||
|
||||
self.rows_ = np.vstack(
|
||||
[
|
||||
self.row_labels_ == label
|
||||
for label in range(n_row_clusters)
|
||||
for _ in range(n_col_clusters)
|
||||
]
|
||||
)
|
||||
self.columns_ = np.vstack(
|
||||
[
|
||||
self.column_labels_ == label
|
||||
for _ in range(n_row_clusters)
|
||||
for label in range(n_col_clusters)
|
||||
]
|
||||
)
|
||||
|
||||
def _fit_best_piecewise(self, vectors, n_best, n_clusters):
|
||||
"""Find the ``n_best`` vectors that are best approximated by piecewise
|
||||
constant vectors.
|
||||
|
||||
The piecewise vectors are found by k-means; the best is chosen
|
||||
according to Euclidean distance.
|
||||
|
||||
"""
|
||||
|
||||
def make_piecewise(v):
|
||||
centroid, labels = self._k_means(v.reshape(-1, 1), n_clusters)
|
||||
return centroid[labels].ravel()
|
||||
|
||||
piecewise_vectors = np.apply_along_axis(make_piecewise, axis=1, arr=vectors)
|
||||
dists = np.apply_along_axis(norm, axis=1, arr=(vectors - piecewise_vectors))
|
||||
result = vectors[np.argsort(dists)[:n_best]]
|
||||
return result
|
||||
|
||||
def _project_and_cluster(self, data, vectors, n_clusters):
|
||||
"""Project ``data`` to ``vectors`` and cluster the result."""
|
||||
projected = safe_sparse_dot(data, vectors)
|
||||
_, labels = self._k_means(projected, n_clusters)
|
||||
return labels
|
||||
@@ -0,0 +1,760 @@
|
||||
# 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
|
||||
import numbers
|
||||
import numpy as np
|
||||
from scipy import sparse
|
||||
from math import sqrt
|
||||
|
||||
from ..metrics import pairwise_distances_argmin
|
||||
from ..metrics.pairwise import euclidean_distances
|
||||
from ..base import (
|
||||
TransformerMixin,
|
||||
ClusterMixin,
|
||||
BaseEstimator,
|
||||
_ClassNamePrefixFeaturesOutMixin,
|
||||
)
|
||||
from ..utils.extmath import row_norms
|
||||
from ..utils import check_scalar, deprecated
|
||||
from ..utils.validation import check_is_fitted
|
||||
from ..exceptions import ConvergenceWarning
|
||||
from . import AgglomerativeClustering
|
||||
from .._config import config_context
|
||||
|
||||
|
||||
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,
|
||||
)
|
||||
new_node2 = _CFNode(
|
||||
threshold=threshold,
|
||||
branching_factor=branching_factor,
|
||||
is_leaf=node.is_leaf,
|
||||
n_features=node.n_features,
|
||||
)
|
||||
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
|
||||
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):
|
||||
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))
|
||||
self.init_sq_norm_ = np.zeros((branching_factor + 1))
|
||||
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, 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])
|
||||
"""
|
||||
|
||||
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
|
||||
|
||||
# TODO: Remove in 1.2
|
||||
# mypy error: Decorated property not supported
|
||||
@deprecated( # type: ignore
|
||||
"`fit_` is deprecated in 1.0 and will be removed in 1.2."
|
||||
)
|
||||
@property
|
||||
def fit_(self):
|
||||
return self._deprecated_fit
|
||||
|
||||
# TODO: Remove in 1.2
|
||||
# mypy error: Decorated property not supported
|
||||
@deprecated( # type: ignore
|
||||
"`partial_fit_` is deprecated in 1.0 and will be removed in 1.2."
|
||||
)
|
||||
@property
|
||||
def partial_fit_(self):
|
||||
return self._deprecated_partial_fit
|
||||
|
||||
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.
|
||||
"""
|
||||
|
||||
# Validating the scalar parameters.
|
||||
check_scalar(
|
||||
self.threshold,
|
||||
"threshold",
|
||||
target_type=numbers.Real,
|
||||
min_val=0.0,
|
||||
include_boundaries="neither",
|
||||
)
|
||||
check_scalar(
|
||||
self.branching_factor,
|
||||
"branching_factor",
|
||||
target_type=numbers.Integral,
|
||||
min_val=1,
|
||||
include_boundaries="neither",
|
||||
)
|
||||
if isinstance(self.n_clusters, numbers.Number):
|
||||
check_scalar(
|
||||
self.n_clusters,
|
||||
"n_clusters",
|
||||
target_type=numbers.Integral,
|
||||
min_val=1,
|
||||
)
|
||||
|
||||
# TODO: Remove deprecated flags in 1.2
|
||||
self._deprecated_fit, self._deprecated_partial_fit = True, False
|
||||
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
|
||||
)
|
||||
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,
|
||||
)
|
||||
|
||||
# To enable getting back subclusters.
|
||||
self.dummy_leaf_ = _CFNode(
|
||||
threshold=threshold,
|
||||
branching_factor=branching_factor,
|
||||
is_leaf=True,
|
||||
n_features=n_features,
|
||||
)
|
||||
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,
|
||||
)
|
||||
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
|
||||
|
||||
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.
|
||||
"""
|
||||
# TODO: Remove deprecated flags in 1.2
|
||||
self._deprecated_partial_fit, self._deprecated_fit = True, False
|
||||
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)
|
||||
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, numbers.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
|
||||
elif clusterer is not None and not hasattr(clusterer, "fit_predict"):
|
||||
raise TypeError(
|
||||
"n_clusters should be an instance of ClusterMixin or an int"
|
||||
)
|
||||
|
||||
# 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)
|
||||
@@ -0,0 +1,538 @@
|
||||
"""Bisecting K-means clustering."""
|
||||
# Author: Michal Krawczyk <mkrwczyk.1@gmail.com>
|
||||
|
||||
import warnings
|
||||
|
||||
import numpy as np
|
||||
import scipy.sparse as sp
|
||||
|
||||
from ._kmeans import _BaseKMeans
|
||||
from ._kmeans import _kmeans_single_elkan
|
||||
from ._kmeans import _kmeans_single_lloyd
|
||||
from ._kmeans import _labels_inertia_threadpool_limit
|
||||
from ._k_means_common import _inertia_dense
|
||||
from ._k_means_common import _inertia_sparse
|
||||
from ..utils.extmath import row_norms
|
||||
from ..utils._openmp_helpers import _openmp_effective_n_threads
|
||||
from ..utils.validation import check_is_fitted
|
||||
from ..utils.validation import _check_sample_weight
|
||||
from ..utils.validation import check_random_state
|
||||
from ..utils.validation import _is_arraylike_not_scalar
|
||||
|
||||
|
||||
class _BisectingTree:
|
||||
"""Tree structure representing the hierarchical clusters of BisectingKMeans."""
|
||||
|
||||
def __init__(self, center, indices, score):
|
||||
"""Create a new cluster node in the tree.
|
||||
|
||||
The node holds the center of this cluster and the indices of the data points
|
||||
that belong to it.
|
||||
"""
|
||||
self.center = center
|
||||
self.indices = indices
|
||||
self.score = score
|
||||
|
||||
self.left = None
|
||||
self.right = None
|
||||
|
||||
def split(self, labels, centers, scores):
|
||||
"""Split the cluster node into two subclusters."""
|
||||
self.left = _BisectingTree(
|
||||
indices=self.indices[labels == 0], center=centers[0], score=scores[0]
|
||||
)
|
||||
self.right = _BisectingTree(
|
||||
indices=self.indices[labels == 1], center=centers[1], score=scores[1]
|
||||
)
|
||||
|
||||
# reset the indices attribute to save memory
|
||||
self.indices = None
|
||||
|
||||
def get_cluster_to_bisect(self):
|
||||
"""Return the cluster node to bisect next.
|
||||
|
||||
It's based on the score of the cluster, which can be either the number of
|
||||
data points assigned to that cluster or the inertia of that cluster
|
||||
(see `bisecting_strategy` for details).
|
||||
"""
|
||||
max_score = None
|
||||
|
||||
for cluster_leaf in self.iter_leaves():
|
||||
if max_score is None or cluster_leaf.score > max_score:
|
||||
max_score = cluster_leaf.score
|
||||
best_cluster_leaf = cluster_leaf
|
||||
|
||||
return best_cluster_leaf
|
||||
|
||||
def iter_leaves(self):
|
||||
"""Iterate over all the cluster leaves in the tree."""
|
||||
if self.left is None:
|
||||
yield self
|
||||
else:
|
||||
yield from self.left.iter_leaves()
|
||||
yield from self.right.iter_leaves()
|
||||
|
||||
|
||||
class BisectingKMeans(_BaseKMeans):
|
||||
"""Bisecting K-Means clustering.
|
||||
|
||||
Read more in the :ref:`User Guide <bisect_k_means>`.
|
||||
|
||||
.. versionadded:: 1.1
|
||||
|
||||
Parameters
|
||||
----------
|
||||
n_clusters : int, default=8
|
||||
The number of clusters to form as well as the number of
|
||||
centroids to generate.
|
||||
|
||||
init : {'k-means++', 'random'} or callable, default='random'
|
||||
Method for initialization:
|
||||
|
||||
'k-means++' : selects initial cluster centers for k-mean
|
||||
clustering in a smart way to speed up convergence. See section
|
||||
Notes in k_init for more details.
|
||||
|
||||
'random': choose `n_clusters` observations (rows) at random from data
|
||||
for the initial centroids.
|
||||
|
||||
If a callable is passed, it should take arguments X, n_clusters and a
|
||||
random state and return an initialization.
|
||||
|
||||
n_init : int, default=1
|
||||
Number of time the inner k-means algorithm will be run with different
|
||||
centroid seeds in each bisection.
|
||||
That will result producing for each bisection best output of n_init
|
||||
consecutive runs in terms of inertia.
|
||||
|
||||
random_state : int, RandomState instance or None, default=None
|
||||
Determines random number generation for centroid initialization
|
||||
in inner K-Means. Use an int to make the randomness deterministic.
|
||||
See :term:`Glossary <random_state>`.
|
||||
|
||||
max_iter : int, default=300
|
||||
Maximum number of iterations of the inner k-means algorithm at each
|
||||
bisection.
|
||||
|
||||
verbose : int, default=0
|
||||
Verbosity mode.
|
||||
|
||||
tol : float, default=1e-4
|
||||
Relative tolerance with regards to Frobenius norm of the difference
|
||||
in the cluster centers of two consecutive iterations to declare
|
||||
convergence. Used in inner k-means algorithm at each bisection to pick
|
||||
best possible clusters.
|
||||
|
||||
copy_x : bool, default=True
|
||||
When pre-computing distances it is more numerically accurate to center
|
||||
the data first. If copy_x is True (default), then the original data is
|
||||
not modified. If False, the original data is modified, and put back
|
||||
before the function returns, but small numerical differences may be
|
||||
introduced by subtracting and then adding the data mean. Note that if
|
||||
the original data is not C-contiguous, a copy will be made even if
|
||||
copy_x is False. If the original data is sparse, but not in CSR format,
|
||||
a copy will be made even if copy_x is False.
|
||||
|
||||
algorithm : {"lloyd", "elkan"}, default="lloyd"
|
||||
Inner K-means algorithm used in bisection.
|
||||
The classical EM-style algorithm is `"lloyd"`.
|
||||
The `"elkan"` variation can be more efficient on some datasets with
|
||||
well-defined clusters, by using the triangle inequality. However it's
|
||||
more memory intensive due to the allocation of an extra array of shape
|
||||
`(n_samples, n_clusters)`.
|
||||
|
||||
bisecting_strategy : {"biggest_inertia", "largest_cluster"},\
|
||||
default="biggest_inertia"
|
||||
Defines how bisection should be performed:
|
||||
|
||||
- "biggest_inertia" means that BisectingKMeans will always check
|
||||
all calculated cluster for cluster with biggest SSE
|
||||
(Sum of squared errors) and bisect it. This approach concentrates on
|
||||
precision, but may be costly in terms of execution time (especially for
|
||||
larger amount of data points).
|
||||
|
||||
- "largest_cluster" - BisectingKMeans will always split cluster with
|
||||
largest amount of points assigned to it from all clusters
|
||||
previously calculated. That should work faster than picking by SSE
|
||||
('biggest_inertia') and may produce similar results in most cases.
|
||||
|
||||
Attributes
|
||||
----------
|
||||
cluster_centers_ : ndarray of shape (n_clusters, n_features)
|
||||
Coordinates of cluster centers. If the algorithm stops before fully
|
||||
converging (see ``tol`` and ``max_iter``), these will not be
|
||||
consistent with ``labels_``.
|
||||
|
||||
labels_ : ndarray of shape (n_samples,)
|
||||
Labels of each point.
|
||||
|
||||
inertia_ : float
|
||||
Sum of squared distances of samples to their closest cluster center,
|
||||
weighted by the sample weights if provided.
|
||||
|
||||
n_features_in_ : int
|
||||
Number of features seen during :term:`fit`.
|
||||
|
||||
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.
|
||||
|
||||
See Also
|
||||
--------
|
||||
KMeans : Original implementation of K-Means algorithm.
|
||||
|
||||
Notes
|
||||
-----
|
||||
It might be inefficient when n_cluster is less than 3, due to unnecassary
|
||||
calculations for that case.
|
||||
|
||||
Examples
|
||||
--------
|
||||
>>> from sklearn.cluster import BisectingKMeans
|
||||
>>> import numpy as np
|
||||
>>> X = np.array([[1, 2], [1, 4], [1, 0],
|
||||
... [10, 2], [10, 4], [10, 0],
|
||||
... [10, 6], [10, 8], [10, 10]])
|
||||
>>> bisect_means = BisectingKMeans(n_clusters=3, random_state=0).fit(X)
|
||||
>>> bisect_means.labels_
|
||||
array([2, 2, 2, 0, 0, 0, 1, 1, 1], dtype=int32)
|
||||
>>> bisect_means.predict([[0, 0], [12, 3]])
|
||||
array([2, 0], dtype=int32)
|
||||
>>> bisect_means.cluster_centers_
|
||||
array([[10., 2.],
|
||||
[10., 8.],
|
||||
[ 1., 2.]])
|
||||
"""
|
||||
|
||||
def __init__(
|
||||
self,
|
||||
n_clusters=8,
|
||||
*,
|
||||
init="random",
|
||||
n_init=1,
|
||||
random_state=None,
|
||||
max_iter=300,
|
||||
verbose=0,
|
||||
tol=1e-4,
|
||||
copy_x=True,
|
||||
algorithm="lloyd",
|
||||
bisecting_strategy="biggest_inertia",
|
||||
):
|
||||
|
||||
super().__init__(
|
||||
n_clusters=n_clusters,
|
||||
init=init,
|
||||
max_iter=max_iter,
|
||||
verbose=verbose,
|
||||
random_state=random_state,
|
||||
tol=tol,
|
||||
n_init=n_init,
|
||||
)
|
||||
|
||||
self.copy_x = copy_x
|
||||
self.algorithm = algorithm
|
||||
self.bisecting_strategy = bisecting_strategy
|
||||
|
||||
def _check_params(self, X):
|
||||
super()._check_params(X)
|
||||
|
||||
# algorithm
|
||||
if self.algorithm not in ("lloyd", "elkan"):
|
||||
raise ValueError(
|
||||
"Algorithm must be either 'lloyd' or 'elkan', "
|
||||
f"got {self.algorithm} instead."
|
||||
)
|
||||
|
||||
# bisecting_strategy
|
||||
if self.bisecting_strategy not in ["biggest_inertia", "largest_cluster"]:
|
||||
raise ValueError(
|
||||
"Bisect Strategy must be 'biggest_inertia' or 'largest_cluster'. "
|
||||
f"Got {self.bisecting_strategy} instead."
|
||||
)
|
||||
|
||||
# init
|
||||
if _is_arraylike_not_scalar(self.init):
|
||||
raise ValueError("BisectingKMeans does not support init as array.")
|
||||
|
||||
def _warn_mkl_vcomp(self, n_active_threads):
|
||||
"""Warn when vcomp and mkl are both present"""
|
||||
warnings.warn(
|
||||
"BisectingKMeans is known to have a memory leak on Windows "
|
||||
"with MKL, when there are less chunks than available "
|
||||
"threads. You can avoid it by setting the environment"
|
||||
f" variable OMP_NUM_THREADS={n_active_threads}."
|
||||
)
|
||||
|
||||
def _inertia_per_cluster(self, X, centers, labels, sample_weight):
|
||||
"""Calculate the sum of squared errors (inertia) per cluster.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
X : {ndarray, csr_matrix} of shape (n_samples, n_features)
|
||||
The input samples.
|
||||
|
||||
centers : ndarray of shape (n_clusters, n_features)
|
||||
The cluster centers.
|
||||
|
||||
labels : ndarray of shape (n_samples,)
|
||||
Index of the cluster each sample belongs to.
|
||||
|
||||
sample_weight : ndarray of shape (n_samples,)
|
||||
The weights for each observation in X.
|
||||
|
||||
Returns
|
||||
-------
|
||||
inertia_per_cluster : ndarray of shape (n_clusters,)
|
||||
Sum of squared errors (inertia) for each cluster.
|
||||
"""
|
||||
_inertia = _inertia_sparse if sp.issparse(X) else _inertia_dense
|
||||
|
||||
inertia_per_cluster = np.empty(centers.shape[1])
|
||||
for label in range(centers.shape[0]):
|
||||
inertia_per_cluster[label] = _inertia(
|
||||
X, sample_weight, centers, labels, self._n_threads, single_label=label
|
||||
)
|
||||
|
||||
return inertia_per_cluster
|
||||
|
||||
def _bisect(self, X, x_squared_norms, sample_weight, cluster_to_bisect):
|
||||
"""Split a cluster into 2 subsclusters.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
X : {ndarray, csr_matrix} of shape (n_samples, n_features)
|
||||
Training instances to cluster.
|
||||
|
||||
x_squared_norms : ndarray of shape (n_samples,)
|
||||
Squared euclidean norm of each data point.
|
||||
|
||||
sample_weight : ndarray of shape (n_samples,)
|
||||
The weights for each observation in X.
|
||||
|
||||
cluster_to_bisect : _BisectingTree node object
|
||||
The cluster node to split.
|
||||
"""
|
||||
X = X[cluster_to_bisect.indices]
|
||||
x_squared_norms = x_squared_norms[cluster_to_bisect.indices]
|
||||
sample_weight = sample_weight[cluster_to_bisect.indices]
|
||||
|
||||
best_inertia = None
|
||||
|
||||
# Split samples in X into 2 clusters.
|
||||
# Repeating `n_init` times to obtain best clusters
|
||||
for _ in range(self.n_init):
|
||||
centers_init = self._init_centroids(
|
||||
X, x_squared_norms, self.init, self._random_state, n_centroids=2
|
||||
)
|
||||
|
||||
labels, inertia, centers, _ = self._kmeans_single(
|
||||
X,
|
||||
sample_weight,
|
||||
centers_init,
|
||||
max_iter=self.max_iter,
|
||||
verbose=self.verbose,
|
||||
tol=self.tol,
|
||||
x_squared_norms=x_squared_norms,
|
||||
n_threads=self._n_threads,
|
||||
)
|
||||
|
||||
# allow small tolerance on the inertia to accommodate for
|
||||
# non-deterministic rounding errors due to parallel computation
|
||||
if best_inertia is None or inertia < best_inertia * (1 - 1e-6):
|
||||
best_labels = labels
|
||||
best_centers = centers
|
||||
best_inertia = inertia
|
||||
|
||||
if self.verbose:
|
||||
print(f"New centroids from bisection: {best_centers}")
|
||||
|
||||
if self.bisecting_strategy == "biggest_inertia":
|
||||
scores = self._inertia_per_cluster(
|
||||
X, best_centers, best_labels, sample_weight
|
||||
)
|
||||
else: # bisecting_strategy == "largest_cluster"
|
||||
scores = np.bincount(best_labels)
|
||||
|
||||
cluster_to_bisect.split(best_labels, best_centers, scores)
|
||||
|
||||
def fit(self, X, y=None, sample_weight=None):
|
||||
"""Compute bisecting k-means clustering.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
X : {array-like, sparse matrix} of shape (n_samples, n_features)
|
||||
|
||||
Training instances to cluster.
|
||||
|
||||
.. note:: The data will be converted to C ordering,
|
||||
which will cause a memory copy
|
||||
if the given data is not C-contiguous.
|
||||
|
||||
y : Ignored
|
||||
Not used, present here for API consistency by convention.
|
||||
|
||||
sample_weight : array-like of shape (n_samples,), default=None
|
||||
The weights for each observation in X. If None, all observations
|
||||
are assigned equal weight.
|
||||
|
||||
Returns
|
||||
-------
|
||||
self
|
||||
Fitted estimator.
|
||||
"""
|
||||
X = self._validate_data(
|
||||
X,
|
||||
accept_sparse="csr",
|
||||
dtype=[np.float64, np.float32],
|
||||
order="C",
|
||||
copy=self.copy_x,
|
||||
accept_large_sparse=False,
|
||||
)
|
||||
|
||||
self._check_params(X)
|
||||
self._random_state = check_random_state(self.random_state)
|
||||
sample_weight = _check_sample_weight(sample_weight, X, dtype=X.dtype)
|
||||
self._n_threads = _openmp_effective_n_threads()
|
||||
|
||||
if self.algorithm == "lloyd" or self.n_clusters == 1:
|
||||
self._kmeans_single = _kmeans_single_lloyd
|
||||
self._check_mkl_vcomp(X, X.shape[0])
|
||||
else:
|
||||
self._kmeans_single = _kmeans_single_elkan
|
||||
|
||||
# Subtract of mean of X for more accurate distance computations
|
||||
if not sp.issparse(X):
|
||||
self._X_mean = X.mean(axis=0)
|
||||
X -= self._X_mean
|
||||
|
||||
# Initialize the hierarchical clusters tree
|
||||
self._bisecting_tree = _BisectingTree(
|
||||
indices=np.arange(X.shape[0]),
|
||||
center=X.mean(axis=0),
|
||||
score=0,
|
||||
)
|
||||
|
||||
x_squared_norms = row_norms(X, squared=True)
|
||||
|
||||
for _ in range(self.n_clusters - 1):
|
||||
# Chose cluster to bisect
|
||||
cluster_to_bisect = self._bisecting_tree.get_cluster_to_bisect()
|
||||
|
||||
# Split this cluster into 2 subclusters
|
||||
self._bisect(X, x_squared_norms, sample_weight, cluster_to_bisect)
|
||||
|
||||
# Aggregate final labels and centers from the bisecting tree
|
||||
self.labels_ = np.full(X.shape[0], -1, dtype=np.int32)
|
||||
self.cluster_centers_ = np.empty((self.n_clusters, X.shape[1]), dtype=X.dtype)
|
||||
|
||||
for i, cluster_node in enumerate(self._bisecting_tree.iter_leaves()):
|
||||
self.labels_[cluster_node.indices] = i
|
||||
self.cluster_centers_[i] = cluster_node.center
|
||||
cluster_node.label = i # label final clusters for future prediction
|
||||
cluster_node.indices = None # release memory
|
||||
|
||||
# Restore original data
|
||||
if not sp.issparse(X):
|
||||
X += self._X_mean
|
||||
self.cluster_centers_ += self._X_mean
|
||||
|
||||
_inertia = _inertia_sparse if sp.issparse(X) else _inertia_dense
|
||||
self.inertia_ = _inertia(
|
||||
X, sample_weight, self.cluster_centers_, self.labels_, self._n_threads
|
||||
)
|
||||
|
||||
self._n_features_out = self.cluster_centers_.shape[0]
|
||||
|
||||
return self
|
||||
|
||||
def predict(self, X):
|
||||
"""Predict which cluster each sample in X belongs to.
|
||||
|
||||
Prediction is made by going down the hierarchical tree
|
||||
in searching of closest leaf cluster.
|
||||
|
||||
In the vector quantization literature, `cluster_centers_` is called
|
||||
the code book and each value returned by `predict` is the index of
|
||||
the closest code in the code book.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
X : {array-like, sparse matrix} of shape (n_samples, n_features)
|
||||
New data to predict.
|
||||
|
||||
Returns
|
||||
-------
|
||||
labels : ndarray of shape (n_samples,)
|
||||
Index of the cluster each sample belongs to.
|
||||
"""
|
||||
check_is_fitted(self)
|
||||
|
||||
X = self._check_test_data(X)
|
||||
x_squared_norms = row_norms(X, squared=True)
|
||||
|
||||
# sample weights are unused but necessary in cython helpers
|
||||
sample_weight = np.ones_like(x_squared_norms)
|
||||
|
||||
labels = self._predict_recursive(
|
||||
X, x_squared_norms, sample_weight, self._bisecting_tree
|
||||
)
|
||||
|
||||
return labels
|
||||
|
||||
def _predict_recursive(self, X, x_squared_norms, sample_weight, cluster_node):
|
||||
"""Predict recursively by going down the hierarchical tree.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
X : {ndarray, csr_matrix} of shape (n_samples, n_features)
|
||||
The data points, currently assigned to `cluster_node`, to predict between
|
||||
the subclusters of this node.
|
||||
|
||||
x_squared_norms : ndarray of shape (n_samples,)
|
||||
Squared euclidean norm of each data point.
|
||||
|
||||
sample_weight : ndarray of shape (n_samples,)
|
||||
The weights for each observation in X.
|
||||
|
||||
cluster_node : _BisectingTree node object
|
||||
The cluster node of the hierarchical tree.
|
||||
|
||||
Returns
|
||||
-------
|
||||
labels : ndarray of shape (n_samples,)
|
||||
Index of the cluster each sample belongs to.
|
||||
"""
|
||||
if cluster_node.left is None:
|
||||
# This cluster has no subcluster. Labels are just the label of the cluster.
|
||||
return np.full(X.shape[0], cluster_node.label, dtype=np.int32)
|
||||
|
||||
# Determine if data points belong to the left or right subcluster
|
||||
centers = np.vstack((cluster_node.left.center, cluster_node.right.center))
|
||||
if hasattr(self, "_X_mean"):
|
||||
centers += self._X_mean
|
||||
|
||||
cluster_labels = _labels_inertia_threadpool_limit(
|
||||
X,
|
||||
sample_weight,
|
||||
x_squared_norms,
|
||||
centers,
|
||||
self._n_threads,
|
||||
return_inertia=False,
|
||||
)
|
||||
mask = cluster_labels == 0
|
||||
|
||||
# Compute the labels for each subset of the data points.
|
||||
labels = np.full(X.shape[0], -1, dtype=np.int32)
|
||||
|
||||
labels[mask] = self._predict_recursive(
|
||||
X[mask], x_squared_norms[mask], sample_weight[mask], cluster_node.left
|
||||
)
|
||||
|
||||
labels[~mask] = self._predict_recursive(
|
||||
X[~mask], x_squared_norms[~mask], sample_weight[~mask], cluster_node.right
|
||||
)
|
||||
|
||||
return labels
|
||||
|
||||
def _more_tags(self):
|
||||
return {"preserves_dtype": [np.float64, np.float32]}
|
||||
@@ -0,0 +1,462 @@
|
||||
"""
|
||||
DBSCAN: Density-Based Spatial Clustering of Applications with Noise
|
||||
"""
|
||||
|
||||
# Author: Robert Layton <robertlayton@gmail.com>
|
||||
# Joel Nothman <joel.nothman@gmail.com>
|
||||
# Lars Buitinck
|
||||
#
|
||||
# License: BSD 3 clause
|
||||
|
||||
import numpy as np
|
||||
import numbers
|
||||
import warnings
|
||||
from scipy import sparse
|
||||
|
||||
from ..utils import check_scalar
|
||||
from ..base import BaseEstimator, ClusterMixin
|
||||
from ..utils.validation import _check_sample_weight
|
||||
from ..neighbors import NearestNeighbors
|
||||
|
||||
from ._dbscan_inner import dbscan_inner
|
||||
|
||||
|
||||
def dbscan(
|
||||
X,
|
||||
eps=0.5,
|
||||
*,
|
||||
min_samples=5,
|
||||
metric="minkowski",
|
||||
metric_params=None,
|
||||
algorithm="auto",
|
||||
leaf_size=30,
|
||||
p=2,
|
||||
sample_weight=None,
|
||||
n_jobs=None,
|
||||
):
|
||||
"""Perform DBSCAN clustering from vector array or distance matrix.
|
||||
|
||||
Read more in the :ref:`User Guide <dbscan>`.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
X : {array-like, sparse (CSR) matrix} of shape (n_samples, n_features) or \
|
||||
(n_samples, n_samples)
|
||||
A feature array, or array of distances between samples if
|
||||
``metric='precomputed'``.
|
||||
|
||||
eps : float, default=0.5
|
||||
The maximum distance between two samples for one to be considered
|
||||
as in the neighborhood of the other. This is not a maximum bound
|
||||
on the distances of points within a cluster. This is the most
|
||||
important DBSCAN parameter to choose appropriately for your data set
|
||||
and distance function.
|
||||
|
||||
min_samples : int, default=5
|
||||
The number of samples (or total weight) in a neighborhood for a point
|
||||
to be considered as a core point. This includes the point itself.
|
||||
|
||||
metric : str or callable, default='minkowski'
|
||||
The metric to use when calculating distance between instances in a
|
||||
feature array. If metric is a string or callable, it must be one of
|
||||
the options allowed by :func:`sklearn.metrics.pairwise_distances` for
|
||||
its metric parameter.
|
||||
If metric is "precomputed", X is assumed to be a distance matrix and
|
||||
must be square during fit.
|
||||
X may be a :term:`sparse graph <sparse graph>`,
|
||||
in which case only "nonzero" elements may be considered neighbors.
|
||||
|
||||
metric_params : dict, default=None
|
||||
Additional keyword arguments for the metric function.
|
||||
|
||||
.. versionadded:: 0.19
|
||||
|
||||
algorithm : {'auto', 'ball_tree', 'kd_tree', 'brute'}, default='auto'
|
||||
The algorithm to be used by the NearestNeighbors module
|
||||
to compute pointwise distances and find nearest neighbors.
|
||||
See NearestNeighbors module documentation for details.
|
||||
|
||||
leaf_size : int, default=30
|
||||
Leaf size passed to BallTree or cKDTree. This can affect the speed
|
||||
of the construction and query, as well as the memory required
|
||||
to store the tree. The optimal value depends
|
||||
on the nature of the problem.
|
||||
|
||||
p : float, default=2
|
||||
The power of the Minkowski metric to be used to calculate distance
|
||||
between points.
|
||||
|
||||
sample_weight : array-like of shape (n_samples,), default=None
|
||||
Weight of each sample, such that a sample with a weight of at least
|
||||
``min_samples`` is by itself a core sample; a sample with negative
|
||||
weight may inhibit its eps-neighbor from being core.
|
||||
Note that weights are absolute, and default to 1.
|
||||
|
||||
n_jobs : int, default=None
|
||||
The number of parallel jobs to run for neighbors search. ``None`` means
|
||||
1 unless in a :obj:`joblib.parallel_backend` context. ``-1`` means
|
||||
using all processors. See :term:`Glossary <n_jobs>` for more details.
|
||||
If precomputed distance are used, parallel execution is not available
|
||||
and thus n_jobs will have no effect.
|
||||
|
||||
Returns
|
||||
-------
|
||||
core_samples : ndarray of shape (n_core_samples,)
|
||||
Indices of core samples.
|
||||
|
||||
labels : ndarray of shape (n_samples,)
|
||||
Cluster labels for each point. Noisy samples are given the label -1.
|
||||
|
||||
See Also
|
||||
--------
|
||||
DBSCAN : An estimator interface for this clustering algorithm.
|
||||
OPTICS : A similar estimator interface clustering at multiple values of
|
||||
eps. Our implementation is optimized for memory usage.
|
||||
|
||||
Notes
|
||||
-----
|
||||
For an example, see :ref:`examples/cluster/plot_dbscan.py
|
||||
<sphx_glr_auto_examples_cluster_plot_dbscan.py>`.
|
||||
|
||||
This implementation bulk-computes all neighborhood queries, which increases
|
||||
the memory complexity to O(n.d) where d is the average number of neighbors,
|
||||
while original DBSCAN had memory complexity O(n). It may attract a higher
|
||||
memory complexity when querying these nearest neighborhoods, depending
|
||||
on the ``algorithm``.
|
||||
|
||||
One way to avoid the query complexity is to pre-compute sparse
|
||||
neighborhoods in chunks using
|
||||
:func:`NearestNeighbors.radius_neighbors_graph
|
||||
<sklearn.neighbors.NearestNeighbors.radius_neighbors_graph>` with
|
||||
``mode='distance'``, then using ``metric='precomputed'`` here.
|
||||
|
||||
Another way to reduce memory and computation time is to remove
|
||||
(near-)duplicate points and use ``sample_weight`` instead.
|
||||
|
||||
:func:`cluster.optics <sklearn.cluster.optics>` provides a similar
|
||||
clustering with lower memory usage.
|
||||
|
||||
References
|
||||
----------
|
||||
Ester, M., H. P. Kriegel, J. Sander, and X. Xu, "A Density-Based
|
||||
Algorithm for Discovering Clusters in Large Spatial Databases with Noise".
|
||||
In: Proceedings of the 2nd International Conference on Knowledge Discovery
|
||||
and Data Mining, Portland, OR, AAAI Press, pp. 226-231. 1996
|
||||
|
||||
Schubert, E., Sander, J., Ester, M., Kriegel, H. P., & Xu, X. (2017).
|
||||
DBSCAN revisited, revisited: why and how you should (still) use DBSCAN.
|
||||
ACM Transactions on Database Systems (TODS), 42(3), 19.
|
||||
"""
|
||||
|
||||
est = DBSCAN(
|
||||
eps=eps,
|
||||
min_samples=min_samples,
|
||||
metric=metric,
|
||||
metric_params=metric_params,
|
||||
algorithm=algorithm,
|
||||
leaf_size=leaf_size,
|
||||
p=p,
|
||||
n_jobs=n_jobs,
|
||||
)
|
||||
est.fit(X, sample_weight=sample_weight)
|
||||
return est.core_sample_indices_, est.labels_
|
||||
|
||||
|
||||
class DBSCAN(ClusterMixin, BaseEstimator):
|
||||
"""Perform DBSCAN clustering from vector array or distance matrix.
|
||||
|
||||
DBSCAN - Density-Based Spatial Clustering of Applications with Noise.
|
||||
Finds core samples of high density and expands clusters from them.
|
||||
Good for data which contains clusters of similar density.
|
||||
|
||||
Read more in the :ref:`User Guide <dbscan>`.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
eps : float, default=0.5
|
||||
The maximum distance between two samples for one to be considered
|
||||
as in the neighborhood of the other. This is not a maximum bound
|
||||
on the distances of points within a cluster. This is the most
|
||||
important DBSCAN parameter to choose appropriately for your data set
|
||||
and distance function.
|
||||
|
||||
min_samples : int, default=5
|
||||
The number of samples (or total weight) in a neighborhood for a point
|
||||
to be considered as a core point. This includes the point itself.
|
||||
|
||||
metric : str, or callable, default='euclidean'
|
||||
The metric to use when calculating distance between instances in a
|
||||
feature array. If metric is a string or callable, it must be one of
|
||||
the options allowed by :func:`sklearn.metrics.pairwise_distances` for
|
||||
its metric parameter.
|
||||
If metric is "precomputed", X is assumed to be a distance matrix and
|
||||
must be square. X may be a :term:`sparse graph`, in which
|
||||
case only "nonzero" elements may be considered neighbors for DBSCAN.
|
||||
|
||||
.. versionadded:: 0.17
|
||||
metric *precomputed* to accept precomputed sparse matrix.
|
||||
|
||||
metric_params : dict, default=None
|
||||
Additional keyword arguments for the metric function.
|
||||
|
||||
.. versionadded:: 0.19
|
||||
|
||||
algorithm : {'auto', 'ball_tree', 'kd_tree', 'brute'}, default='auto'
|
||||
The algorithm to be used by the NearestNeighbors module
|
||||
to compute pointwise distances and find nearest neighbors.
|
||||
See NearestNeighbors module documentation for details.
|
||||
|
||||
leaf_size : int, default=30
|
||||
Leaf size passed to BallTree or cKDTree. This can affect the speed
|
||||
of the construction and query, as well as the memory required
|
||||
to store the tree. The optimal value depends
|
||||
on the nature of the problem.
|
||||
|
||||
p : float, default=None
|
||||
The power of the Minkowski metric to be used to calculate distance
|
||||
between points. If None, then ``p=2`` (equivalent to the Euclidean
|
||||
distance).
|
||||
|
||||
n_jobs : int, default=None
|
||||
The number of parallel jobs to run.
|
||||
``None`` means 1 unless in a :obj:`joblib.parallel_backend` context.
|
||||
``-1`` means using all processors. See :term:`Glossary <n_jobs>`
|
||||
for more details.
|
||||
|
||||
Attributes
|
||||
----------
|
||||
core_sample_indices_ : ndarray of shape (n_core_samples,)
|
||||
Indices of core samples.
|
||||
|
||||
components_ : ndarray of shape (n_core_samples, n_features)
|
||||
Copy of each core sample found by training.
|
||||
|
||||
labels_ : ndarray of shape (n_samples)
|
||||
Cluster labels for each point in the dataset given to fit().
|
||||
Noisy samples are given the label -1.
|
||||
|
||||
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
|
||||
--------
|
||||
OPTICS : A similar clustering at multiple values of eps. Our implementation
|
||||
is optimized for memory usage.
|
||||
|
||||
Notes
|
||||
-----
|
||||
For an example, see :ref:`examples/cluster/plot_dbscan.py
|
||||
<sphx_glr_auto_examples_cluster_plot_dbscan.py>`.
|
||||
|
||||
This implementation bulk-computes all neighborhood queries, which increases
|
||||
the memory complexity to O(n.d) where d is the average number of neighbors,
|
||||
while original DBSCAN had memory complexity O(n). It may attract a higher
|
||||
memory complexity when querying these nearest neighborhoods, depending
|
||||
on the ``algorithm``.
|
||||
|
||||
One way to avoid the query complexity is to pre-compute sparse
|
||||
neighborhoods in chunks using
|
||||
:func:`NearestNeighbors.radius_neighbors_graph
|
||||
<sklearn.neighbors.NearestNeighbors.radius_neighbors_graph>` with
|
||||
``mode='distance'``, then using ``metric='precomputed'`` here.
|
||||
|
||||
Another way to reduce memory and computation time is to remove
|
||||
(near-)duplicate points and use ``sample_weight`` instead.
|
||||
|
||||
:class:`cluster.OPTICS` provides a similar clustering with lower memory
|
||||
usage.
|
||||
|
||||
References
|
||||
----------
|
||||
Ester, M., H. P. Kriegel, J. Sander, and X. Xu, "A Density-Based
|
||||
Algorithm for Discovering Clusters in Large Spatial Databases with Noise".
|
||||
In: Proceedings of the 2nd International Conference on Knowledge Discovery
|
||||
and Data Mining, Portland, OR, AAAI Press, pp. 226-231. 1996
|
||||
|
||||
Schubert, E., Sander, J., Ester, M., Kriegel, H. P., & Xu, X. (2017).
|
||||
DBSCAN revisited, revisited: why and how you should (still) use DBSCAN.
|
||||
ACM Transactions on Database Systems (TODS), 42(3), 19.
|
||||
|
||||
Examples
|
||||
--------
|
||||
>>> from sklearn.cluster import DBSCAN
|
||||
>>> import numpy as np
|
||||
>>> X = np.array([[1, 2], [2, 2], [2, 3],
|
||||
... [8, 7], [8, 8], [25, 80]])
|
||||
>>> clustering = DBSCAN(eps=3, min_samples=2).fit(X)
|
||||
>>> clustering.labels_
|
||||
array([ 0, 0, 0, 1, 1, -1])
|
||||
>>> clustering
|
||||
DBSCAN(eps=3, min_samples=2)
|
||||
"""
|
||||
|
||||
def __init__(
|
||||
self,
|
||||
eps=0.5,
|
||||
*,
|
||||
min_samples=5,
|
||||
metric="euclidean",
|
||||
metric_params=None,
|
||||
algorithm="auto",
|
||||
leaf_size=30,
|
||||
p=None,
|
||||
n_jobs=None,
|
||||
):
|
||||
self.eps = eps
|
||||
self.min_samples = min_samples
|
||||
self.metric = metric
|
||||
self.metric_params = metric_params
|
||||
self.algorithm = algorithm
|
||||
self.leaf_size = leaf_size
|
||||
self.p = p
|
||||
self.n_jobs = n_jobs
|
||||
|
||||
def fit(self, X, y=None, sample_weight=None):
|
||||
"""Perform DBSCAN clustering from features, or distance matrix.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
X : {array-like, sparse matrix} of shape (n_samples, n_features), or \
|
||||
(n_samples, n_samples)
|
||||
Training instances to cluster, or distances between instances if
|
||||
``metric='precomputed'``. If a sparse matrix is provided, it will
|
||||
be converted into a sparse ``csr_matrix``.
|
||||
|
||||
y : Ignored
|
||||
Not used, present here for API consistency by convention.
|
||||
|
||||
sample_weight : array-like of shape (n_samples,), default=None
|
||||
Weight of each sample, such that a sample with a weight of at least
|
||||
``min_samples`` is by itself a core sample; a sample with a
|
||||
negative weight may inhibit its eps-neighbor from being core.
|
||||
Note that weights are absolute, and default to 1.
|
||||
|
||||
Returns
|
||||
-------
|
||||
self : object
|
||||
Returns a fitted instance of self.
|
||||
"""
|
||||
X = self._validate_data(X, accept_sparse="csr")
|
||||
|
||||
if sample_weight is not None:
|
||||
sample_weight = _check_sample_weight(sample_weight, X)
|
||||
|
||||
# Calculate neighborhood for all samples. This leaves the original
|
||||
# point in, which needs to be considered later (i.e. point i is in the
|
||||
# neighborhood of point i. While True, its useless information)
|
||||
if self.metric == "precomputed" and sparse.issparse(X):
|
||||
# set the diagonal to explicit values, as a point is its own
|
||||
# neighbor
|
||||
with warnings.catch_warnings():
|
||||
warnings.simplefilter("ignore", sparse.SparseEfficiencyWarning)
|
||||
X.setdiag(X.diagonal()) # XXX: modifies X's internals in-place
|
||||
|
||||
# Validating the scalar parameters.
|
||||
check_scalar(
|
||||
self.eps,
|
||||
"eps",
|
||||
target_type=numbers.Real,
|
||||
min_val=0.0,
|
||||
include_boundaries="neither",
|
||||
)
|
||||
check_scalar(
|
||||
self.min_samples,
|
||||
"min_samples",
|
||||
target_type=numbers.Integral,
|
||||
min_val=1,
|
||||
include_boundaries="left",
|
||||
)
|
||||
check_scalar(
|
||||
self.leaf_size,
|
||||
"leaf_size",
|
||||
target_type=numbers.Integral,
|
||||
min_val=1,
|
||||
include_boundaries="left",
|
||||
)
|
||||
if self.p is not None:
|
||||
check_scalar(
|
||||
self.p,
|
||||
"p",
|
||||
target_type=numbers.Real,
|
||||
min_val=0.0,
|
||||
include_boundaries="left",
|
||||
)
|
||||
if self.n_jobs is not None:
|
||||
check_scalar(self.n_jobs, "n_jobs", target_type=numbers.Integral)
|
||||
|
||||
neighbors_model = NearestNeighbors(
|
||||
radius=self.eps,
|
||||
algorithm=self.algorithm,
|
||||
leaf_size=self.leaf_size,
|
||||
metric=self.metric,
|
||||
metric_params=self.metric_params,
|
||||
p=self.p,
|
||||
n_jobs=self.n_jobs,
|
||||
)
|
||||
neighbors_model.fit(X)
|
||||
# This has worst case O(n^2) memory complexity
|
||||
neighborhoods = neighbors_model.radius_neighbors(X, return_distance=False)
|
||||
|
||||
if sample_weight is None:
|
||||
n_neighbors = np.array([len(neighbors) for neighbors in neighborhoods])
|
||||
else:
|
||||
n_neighbors = np.array(
|
||||
[np.sum(sample_weight[neighbors]) for neighbors in neighborhoods]
|
||||
)
|
||||
|
||||
# Initially, all samples are noise.
|
||||
labels = np.full(X.shape[0], -1, dtype=np.intp)
|
||||
|
||||
# A list of all core samples found.
|
||||
core_samples = np.asarray(n_neighbors >= self.min_samples, dtype=np.uint8)
|
||||
dbscan_inner(core_samples, neighborhoods, labels)
|
||||
|
||||
self.core_sample_indices_ = np.where(core_samples)[0]
|
||||
self.labels_ = labels
|
||||
|
||||
if len(self.core_sample_indices_):
|
||||
# fix for scipy sparse indexing issue
|
||||
self.components_ = X[self.core_sample_indices_].copy()
|
||||
else:
|
||||
# no core samples
|
||||
self.components_ = np.empty((0, X.shape[1]))
|
||||
return self
|
||||
|
||||
def fit_predict(self, X, y=None, sample_weight=None):
|
||||
"""Compute clusters from a data or distance matrix and predict labels.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
X : {array-like, sparse matrix} of shape (n_samples, n_features), or \
|
||||
(n_samples, n_samples)
|
||||
Training instances to cluster, or distances between instances if
|
||||
``metric='precomputed'``. If a sparse matrix is provided, it will
|
||||
be converted into a sparse ``csr_matrix``.
|
||||
|
||||
y : Ignored
|
||||
Not used, present here for API consistency by convention.
|
||||
|
||||
sample_weight : array-like of shape (n_samples,), default=None
|
||||
Weight of each sample, such that a sample with a weight of at least
|
||||
``min_samples`` is by itself a core sample; a sample with a
|
||||
negative weight may inhibit its eps-neighbor from being core.
|
||||
Note that weights are absolute, and default to 1.
|
||||
|
||||
Returns
|
||||
-------
|
||||
labels : ndarray of shape (n_samples,)
|
||||
Cluster labels. Noisy samples are given the label -1.
|
||||
"""
|
||||
self.fit(X, sample_weight=sample_weight)
|
||||
return self.labels_
|
||||
|
||||
def _more_tags(self):
|
||||
return {"pairwise": self.metric == "precomputed"}
|
||||
Binary file not shown.
@@ -0,0 +1,75 @@
|
||||
"""
|
||||
Feature agglomeration. Base classes and functions for performing feature
|
||||
agglomeration.
|
||||
"""
|
||||
# Author: V. Michel, A. Gramfort
|
||||
# License: BSD 3 clause
|
||||
|
||||
import numpy as np
|
||||
|
||||
from ..base import TransformerMixin
|
||||
from ..utils.validation import check_is_fitted
|
||||
from scipy.sparse import issparse
|
||||
|
||||
###############################################################################
|
||||
# Mixin class for feature agglomeration.
|
||||
|
||||
|
||||
class AgglomerationTransform(TransformerMixin):
|
||||
"""
|
||||
A class for feature agglomeration via the transform interface.
|
||||
"""
|
||||
|
||||
def transform(self, X):
|
||||
"""
|
||||
Transform a new matrix using the built clustering.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
X : array-like of shape (n_samples, n_features) or \
|
||||
(n_samples, n_samples)
|
||||
A M by N array of M observations in N dimensions or a length
|
||||
M array of M one-dimensional observations.
|
||||
|
||||
Returns
|
||||
-------
|
||||
Y : ndarray of shape (n_samples, n_clusters) or (n_clusters,)
|
||||
The pooled values for each feature cluster.
|
||||
"""
|
||||
check_is_fitted(self)
|
||||
|
||||
X = self._validate_data(X, reset=False)
|
||||
if self.pooling_func == np.mean and not issparse(X):
|
||||
size = np.bincount(self.labels_)
|
||||
n_samples = X.shape[0]
|
||||
# a fast way to compute the mean of grouped features
|
||||
nX = np.array(
|
||||
[np.bincount(self.labels_, X[i, :]) / size for i in range(n_samples)]
|
||||
)
|
||||
else:
|
||||
nX = [
|
||||
self.pooling_func(X[:, self.labels_ == l], axis=1)
|
||||
for l in np.unique(self.labels_)
|
||||
]
|
||||
nX = np.array(nX).T
|
||||
return nX
|
||||
|
||||
def inverse_transform(self, Xred):
|
||||
"""
|
||||
Inverse the transformation and return a vector of size `n_features`.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
Xred : array-like of shape (n_samples, n_clusters) or (n_clusters,)
|
||||
The values to be assigned to each cluster of samples.
|
||||
|
||||
Returns
|
||||
-------
|
||||
X : ndarray of shape (n_samples, n_features) or (n_features,)
|
||||
A vector of size `n_samples` with the values of `Xred` assigned to
|
||||
each of the cluster of samples.
|
||||
"""
|
||||
check_is_fitted(self)
|
||||
|
||||
unil, inverse = np.unique(self.labels_, return_inverse=True)
|
||||
return Xred[..., inverse]
|
||||
Binary file not shown.
Binary file not shown.
@@ -0,0 +1,20 @@
|
||||
from cython cimport floating
|
||||
cimport numpy as np
|
||||
|
||||
|
||||
cdef floating _euclidean_dense_dense(floating*, floating*, int, bint) nogil
|
||||
|
||||
cdef floating _euclidean_sparse_dense(floating[::1], int[::1], floating[::1],
|
||||
floating, bint) nogil
|
||||
|
||||
cpdef void _relocate_empty_clusters_dense(
|
||||
floating[:, ::1], floating[::1], floating[:, ::1],
|
||||
floating[:, ::1], floating[::1], int[::1])
|
||||
|
||||
cpdef void _relocate_empty_clusters_sparse(
|
||||
floating[::1], int[::1], int[::1], floating[::1], floating[:, ::1],
|
||||
floating[:, ::1], floating[::1], int[::1])
|
||||
|
||||
cdef void _average_centers(floating[:, ::1], floating[::1])
|
||||
|
||||
cdef void _center_shift(floating[:, ::1], floating[:, ::1], floating[::1])
|
||||
Binary file not shown.
Binary file not shown.
Binary file not shown.
File diff suppressed because it is too large
Load Diff
@@ -0,0 +1,514 @@
|
||||
"""Mean shift clustering algorithm.
|
||||
|
||||
Mean shift clustering aims to discover *blobs* in a smooth density of
|
||||
samples. It is a centroid based algorithm, which works by updating candidates
|
||||
for centroids to be the mean of the points within a given region. These
|
||||
candidates are then filtered in a post-processing stage to eliminate
|
||||
near-duplicates to form the final set of centroids.
|
||||
|
||||
Seeding is performed using a binning technique for scalability.
|
||||
"""
|
||||
|
||||
# Authors: Conrad Lee <conradlee@gmail.com>
|
||||
# Alexandre Gramfort <alexandre.gramfort@inria.fr>
|
||||
# Gael Varoquaux <gael.varoquaux@normalesup.org>
|
||||
# Martino Sorbaro <martino.sorbaro@ed.ac.uk>
|
||||
|
||||
import numpy as np
|
||||
import warnings
|
||||
from joblib import Parallel
|
||||
|
||||
from collections import defaultdict
|
||||
from ..utils.validation import check_is_fitted
|
||||
from ..utils.fixes import delayed
|
||||
from ..utils import check_random_state, gen_batches, check_array
|
||||
from ..base import BaseEstimator, ClusterMixin
|
||||
from ..neighbors import NearestNeighbors
|
||||
from ..metrics.pairwise import pairwise_distances_argmin
|
||||
from .._config import config_context
|
||||
|
||||
|
||||
def estimate_bandwidth(X, *, quantile=0.3, n_samples=None, random_state=0, n_jobs=None):
|
||||
"""Estimate the bandwidth to use with the mean-shift algorithm.
|
||||
|
||||
That this function takes time at least quadratic in n_samples. For large
|
||||
datasets, it's wise to set that parameter to a small value.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
X : array-like of shape (n_samples, n_features)
|
||||
Input points.
|
||||
|
||||
quantile : float, default=0.3
|
||||
Should be between [0, 1]
|
||||
0.5 means that the median of all pairwise distances is used.
|
||||
|
||||
n_samples : int, default=None
|
||||
The number of samples to use. If not given, all samples are used.
|
||||
|
||||
random_state : int, RandomState instance, default=None
|
||||
The generator used to randomly select the samples from input points
|
||||
for bandwidth estimation. Use an int to make the randomness
|
||||
deterministic.
|
||||
See :term:`Glossary <random_state>`.
|
||||
|
||||
n_jobs : int, default=None
|
||||
The number of parallel jobs to run for neighbors search.
|
||||
``None`` means 1 unless in a :obj:`joblib.parallel_backend` context.
|
||||
``-1`` means using all processors. See :term:`Glossary <n_jobs>`
|
||||
for more details.
|
||||
|
||||
Returns
|
||||
-------
|
||||
bandwidth : float
|
||||
The bandwidth parameter.
|
||||
"""
|
||||
X = check_array(X)
|
||||
|
||||
random_state = check_random_state(random_state)
|
||||
if n_samples is not None:
|
||||
idx = random_state.permutation(X.shape[0])[:n_samples]
|
||||
X = X[idx]
|
||||
n_neighbors = int(X.shape[0] * quantile)
|
||||
if n_neighbors < 1: # cannot fit NearestNeighbors with n_neighbors = 0
|
||||
n_neighbors = 1
|
||||
nbrs = NearestNeighbors(n_neighbors=n_neighbors, n_jobs=n_jobs)
|
||||
nbrs.fit(X)
|
||||
|
||||
bandwidth = 0.0
|
||||
for batch in gen_batches(len(X), 500):
|
||||
d, _ = nbrs.kneighbors(X[batch, :], return_distance=True)
|
||||
bandwidth += np.max(d, axis=1).sum()
|
||||
|
||||
return bandwidth / X.shape[0]
|
||||
|
||||
|
||||
# separate function for each seed's iterative loop
|
||||
def _mean_shift_single_seed(my_mean, X, nbrs, max_iter):
|
||||
# For each seed, climb gradient until convergence or max_iter
|
||||
bandwidth = nbrs.get_params()["radius"]
|
||||
stop_thresh = 1e-3 * bandwidth # when mean has converged
|
||||
completed_iterations = 0
|
||||
while True:
|
||||
# Find mean of points within bandwidth
|
||||
i_nbrs = nbrs.radius_neighbors([my_mean], bandwidth, return_distance=False)[0]
|
||||
points_within = X[i_nbrs]
|
||||
if len(points_within) == 0:
|
||||
break # Depending on seeding strategy this condition may occur
|
||||
my_old_mean = my_mean # save the old mean
|
||||
my_mean = np.mean(points_within, axis=0)
|
||||
# If converged or at max_iter, adds the cluster
|
||||
if (
|
||||
np.linalg.norm(my_mean - my_old_mean) < stop_thresh
|
||||
or completed_iterations == max_iter
|
||||
):
|
||||
break
|
||||
completed_iterations += 1
|
||||
return tuple(my_mean), len(points_within), completed_iterations
|
||||
|
||||
|
||||
def mean_shift(
|
||||
X,
|
||||
*,
|
||||
bandwidth=None,
|
||||
seeds=None,
|
||||
bin_seeding=False,
|
||||
min_bin_freq=1,
|
||||
cluster_all=True,
|
||||
max_iter=300,
|
||||
n_jobs=None,
|
||||
):
|
||||
"""Perform mean shift clustering of data using a flat kernel.
|
||||
|
||||
Read more in the :ref:`User Guide <mean_shift>`.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
|
||||
X : array-like of shape (n_samples, n_features)
|
||||
Input data.
|
||||
|
||||
bandwidth : float, default=None
|
||||
Kernel bandwidth.
|
||||
|
||||
If bandwidth is not given, it is determined using a heuristic based on
|
||||
the median of all pairwise distances. This will take quadratic time in
|
||||
the number of samples. The sklearn.cluster.estimate_bandwidth function
|
||||
can be used to do this more efficiently.
|
||||
|
||||
seeds : array-like of shape (n_seeds, n_features) or None
|
||||
Point used as initial kernel locations. If None and bin_seeding=False,
|
||||
each data point is used as a seed. If None and bin_seeding=True,
|
||||
see bin_seeding.
|
||||
|
||||
bin_seeding : bool, default=False
|
||||
If true, initial kernel locations are not locations of all
|
||||
points, but rather the location of the discretized version of
|
||||
points, where points are binned onto a grid whose coarseness
|
||||
corresponds to the bandwidth. Setting this option to True will speed
|
||||
up the algorithm because fewer seeds will be initialized.
|
||||
Ignored if seeds argument is not None.
|
||||
|
||||
min_bin_freq : int, default=1
|
||||
To speed up the algorithm, accept only those bins with at least
|
||||
min_bin_freq points as seeds.
|
||||
|
||||
cluster_all : bool, default=True
|
||||
If true, then all points are clustered, even those orphans that are
|
||||
not within any kernel. Orphans are assigned to the nearest kernel.
|
||||
If false, then orphans are given cluster label -1.
|
||||
|
||||
max_iter : int, default=300
|
||||
Maximum number of iterations, per seed point before the clustering
|
||||
operation terminates (for that seed point), if has not converged yet.
|
||||
|
||||
n_jobs : int, default=None
|
||||
The number of jobs to use for the computation. This works by computing
|
||||
each of the n_init runs in parallel.
|
||||
|
||||
``None`` means 1 unless in a :obj:`joblib.parallel_backend` context.
|
||||
``-1`` means using all processors. See :term:`Glossary <n_jobs>`
|
||||
for more details.
|
||||
|
||||
.. versionadded:: 0.17
|
||||
Parallel Execution using *n_jobs*.
|
||||
|
||||
Returns
|
||||
-------
|
||||
|
||||
cluster_centers : ndarray of shape (n_clusters, n_features)
|
||||
Coordinates of cluster centers.
|
||||
|
||||
labels : ndarray of shape (n_samples,)
|
||||
Cluster labels for each point.
|
||||
|
||||
Notes
|
||||
-----
|
||||
For an example, see :ref:`examples/cluster/plot_mean_shift.py
|
||||
<sphx_glr_auto_examples_cluster_plot_mean_shift.py>`.
|
||||
"""
|
||||
model = MeanShift(
|
||||
bandwidth=bandwidth,
|
||||
seeds=seeds,
|
||||
min_bin_freq=min_bin_freq,
|
||||
bin_seeding=bin_seeding,
|
||||
cluster_all=cluster_all,
|
||||
n_jobs=n_jobs,
|
||||
max_iter=max_iter,
|
||||
).fit(X)
|
||||
return model.cluster_centers_, model.labels_
|
||||
|
||||
|
||||
def get_bin_seeds(X, bin_size, min_bin_freq=1):
|
||||
"""Find seeds for mean_shift.
|
||||
|
||||
Finds seeds by first binning data onto a grid whose lines are
|
||||
spaced bin_size apart, and then choosing those bins with at least
|
||||
min_bin_freq points.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
|
||||
X : array-like of shape (n_samples, n_features)
|
||||
Input points, the same points that will be used in mean_shift.
|
||||
|
||||
bin_size : float
|
||||
Controls the coarseness of the binning. Smaller values lead
|
||||
to more seeding (which is computationally more expensive). If you're
|
||||
not sure how to set this, set it to the value of the bandwidth used
|
||||
in clustering.mean_shift.
|
||||
|
||||
min_bin_freq : int, default=1
|
||||
Only bins with at least min_bin_freq will be selected as seeds.
|
||||
Raising this value decreases the number of seeds found, which
|
||||
makes mean_shift computationally cheaper.
|
||||
|
||||
Returns
|
||||
-------
|
||||
bin_seeds : array-like of shape (n_samples, n_features)
|
||||
Points used as initial kernel positions in clustering.mean_shift.
|
||||
"""
|
||||
if bin_size == 0:
|
||||
return X
|
||||
|
||||
# Bin points
|
||||
bin_sizes = defaultdict(int)
|
||||
for point in X:
|
||||
binned_point = np.round(point / bin_size)
|
||||
bin_sizes[tuple(binned_point)] += 1
|
||||
|
||||
# Select only those bins as seeds which have enough members
|
||||
bin_seeds = np.array(
|
||||
[point for point, freq in bin_sizes.items() if freq >= min_bin_freq],
|
||||
dtype=np.float32,
|
||||
)
|
||||
if len(bin_seeds) == len(X):
|
||||
warnings.warn(
|
||||
"Binning data failed with provided bin_size=%f, using data points as seeds."
|
||||
% bin_size
|
||||
)
|
||||
return X
|
||||
bin_seeds = bin_seeds * bin_size
|
||||
return bin_seeds
|
||||
|
||||
|
||||
class MeanShift(ClusterMixin, BaseEstimator):
|
||||
"""Mean shift clustering using a flat kernel.
|
||||
|
||||
Mean shift clustering aims to discover "blobs" in a smooth density of
|
||||
samples. It is a centroid-based algorithm, which works by updating
|
||||
candidates for centroids to be the mean of the points within a given
|
||||
region. These candidates are then filtered in a post-processing stage to
|
||||
eliminate near-duplicates to form the final set of centroids.
|
||||
|
||||
Seeding is performed using a binning technique for scalability.
|
||||
|
||||
Read more in the :ref:`User Guide <mean_shift>`.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
bandwidth : float, default=None
|
||||
Bandwidth used in the RBF kernel.
|
||||
|
||||
If not given, the bandwidth is estimated using
|
||||
sklearn.cluster.estimate_bandwidth; see the documentation for that
|
||||
function for hints on scalability (see also the Notes, below).
|
||||
|
||||
seeds : array-like of shape (n_samples, n_features), default=None
|
||||
Seeds used to initialize kernels. If not set,
|
||||
the seeds are calculated by clustering.get_bin_seeds
|
||||
with bandwidth as the grid size and default values for
|
||||
other parameters.
|
||||
|
||||
bin_seeding : bool, default=False
|
||||
If true, initial kernel locations are not locations of all
|
||||
points, but rather the location of the discretized version of
|
||||
points, where points are binned onto a grid whose coarseness
|
||||
corresponds to the bandwidth. Setting this option to True will speed
|
||||
up the algorithm because fewer seeds will be initialized.
|
||||
The default value is False.
|
||||
Ignored if seeds argument is not None.
|
||||
|
||||
min_bin_freq : int, default=1
|
||||
To speed up the algorithm, accept only those bins with at least
|
||||
min_bin_freq points as seeds.
|
||||
|
||||
cluster_all : bool, default=True
|
||||
If true, then all points are clustered, even those orphans that are
|
||||
not within any kernel. Orphans are assigned to the nearest kernel.
|
||||
If false, then orphans are given cluster label -1.
|
||||
|
||||
n_jobs : int, default=None
|
||||
The number of jobs to use for the computation. This works by computing
|
||||
each of the n_init runs in parallel.
|
||||
|
||||
``None`` means 1 unless in a :obj:`joblib.parallel_backend` context.
|
||||
``-1`` means using all processors. See :term:`Glossary <n_jobs>`
|
||||
for more details.
|
||||
|
||||
max_iter : int, default=300
|
||||
Maximum number of iterations, per seed point before the clustering
|
||||
operation terminates (for that seed point), if has not converged yet.
|
||||
|
||||
.. versionadded:: 0.22
|
||||
|
||||
Attributes
|
||||
----------
|
||||
cluster_centers_ : ndarray of shape (n_clusters, n_features)
|
||||
Coordinates of cluster centers.
|
||||
|
||||
labels_ : ndarray of shape (n_samples,)
|
||||
Labels of each point.
|
||||
|
||||
n_iter_ : int
|
||||
Maximum number of iterations performed on each seed.
|
||||
|
||||
.. versionadded:: 0.22
|
||||
|
||||
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
|
||||
--------
|
||||
KMeans : K-Means clustering.
|
||||
|
||||
Notes
|
||||
-----
|
||||
|
||||
Scalability:
|
||||
|
||||
Because this implementation uses a flat kernel and
|
||||
a Ball Tree to look up members of each kernel, the complexity will tend
|
||||
towards O(T*n*log(n)) in lower dimensions, with n the number of samples
|
||||
and T the number of points. In higher dimensions the complexity will
|
||||
tend towards O(T*n^2).
|
||||
|
||||
Scalability can be boosted by using fewer seeds, for example by using
|
||||
a higher value of min_bin_freq in the get_bin_seeds function.
|
||||
|
||||
Note that the estimate_bandwidth function is much less scalable than the
|
||||
mean shift algorithm and will be the bottleneck if it is used.
|
||||
|
||||
References
|
||||
----------
|
||||
|
||||
Dorin Comaniciu and Peter Meer, "Mean Shift: A robust approach toward
|
||||
feature space analysis". IEEE Transactions on Pattern Analysis and
|
||||
Machine Intelligence. 2002. pp. 603-619.
|
||||
|
||||
Examples
|
||||
--------
|
||||
>>> from sklearn.cluster import MeanShift
|
||||
>>> import numpy as np
|
||||
>>> X = np.array([[1, 1], [2, 1], [1, 0],
|
||||
... [4, 7], [3, 5], [3, 6]])
|
||||
>>> clustering = MeanShift(bandwidth=2).fit(X)
|
||||
>>> clustering.labels_
|
||||
array([1, 1, 1, 0, 0, 0])
|
||||
>>> clustering.predict([[0, 0], [5, 5]])
|
||||
array([1, 0])
|
||||
>>> clustering
|
||||
MeanShift(bandwidth=2)
|
||||
"""
|
||||
|
||||
def __init__(
|
||||
self,
|
||||
*,
|
||||
bandwidth=None,
|
||||
seeds=None,
|
||||
bin_seeding=False,
|
||||
min_bin_freq=1,
|
||||
cluster_all=True,
|
||||
n_jobs=None,
|
||||
max_iter=300,
|
||||
):
|
||||
self.bandwidth = bandwidth
|
||||
self.seeds = seeds
|
||||
self.bin_seeding = bin_seeding
|
||||
self.cluster_all = cluster_all
|
||||
self.min_bin_freq = min_bin_freq
|
||||
self.n_jobs = n_jobs
|
||||
self.max_iter = max_iter
|
||||
|
||||
def fit(self, X, y=None):
|
||||
"""Perform clustering.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
X : array-like of shape (n_samples, n_features)
|
||||
Samples to cluster.
|
||||
|
||||
y : Ignored
|
||||
Not used, present for API consistency by convention.
|
||||
|
||||
Returns
|
||||
-------
|
||||
self : object
|
||||
Fitted instance.
|
||||
"""
|
||||
X = self._validate_data(X)
|
||||
bandwidth = self.bandwidth
|
||||
if bandwidth is None:
|
||||
bandwidth = estimate_bandwidth(X, n_jobs=self.n_jobs)
|
||||
elif bandwidth <= 0:
|
||||
raise ValueError(
|
||||
"bandwidth needs to be greater than zero or None, got %f" % bandwidth
|
||||
)
|
||||
|
||||
seeds = self.seeds
|
||||
if seeds is None:
|
||||
if self.bin_seeding:
|
||||
seeds = get_bin_seeds(X, bandwidth, self.min_bin_freq)
|
||||
else:
|
||||
seeds = X
|
||||
n_samples, n_features = X.shape
|
||||
center_intensity_dict = {}
|
||||
|
||||
# We use n_jobs=1 because this will be used in nested calls under
|
||||
# parallel calls to _mean_shift_single_seed so there is no need for
|
||||
# for further parallelism.
|
||||
nbrs = NearestNeighbors(radius=bandwidth, n_jobs=1).fit(X)
|
||||
|
||||
# execute iterations on all seeds in parallel
|
||||
all_res = Parallel(n_jobs=self.n_jobs)(
|
||||
delayed(_mean_shift_single_seed)(seed, X, nbrs, self.max_iter)
|
||||
for seed in seeds
|
||||
)
|
||||
# copy results in a dictionary
|
||||
for i in range(len(seeds)):
|
||||
if all_res[i][1]: # i.e. len(points_within) > 0
|
||||
center_intensity_dict[all_res[i][0]] = all_res[i][1]
|
||||
|
||||
self.n_iter_ = max([x[2] for x in all_res])
|
||||
|
||||
if not center_intensity_dict:
|
||||
# nothing near seeds
|
||||
raise ValueError(
|
||||
"No point was within bandwidth=%f of any seed. Try a different seeding"
|
||||
" strategy or increase the bandwidth."
|
||||
% bandwidth
|
||||
)
|
||||
|
||||
# POST PROCESSING: remove near duplicate points
|
||||
# If the distance between two kernels is less than the bandwidth,
|
||||
# then we have to remove one because it is a duplicate. Remove the
|
||||
# one with fewer points.
|
||||
|
||||
sorted_by_intensity = sorted(
|
||||
center_intensity_dict.items(),
|
||||
key=lambda tup: (tup[1], tup[0]),
|
||||
reverse=True,
|
||||
)
|
||||
sorted_centers = np.array([tup[0] for tup in sorted_by_intensity])
|
||||
unique = np.ones(len(sorted_centers), dtype=bool)
|
||||
nbrs = NearestNeighbors(radius=bandwidth, n_jobs=self.n_jobs).fit(
|
||||
sorted_centers
|
||||
)
|
||||
for i, center in enumerate(sorted_centers):
|
||||
if unique[i]:
|
||||
neighbor_idxs = nbrs.radius_neighbors([center], return_distance=False)[
|
||||
0
|
||||
]
|
||||
unique[neighbor_idxs] = 0
|
||||
unique[i] = 1 # leave the current point as unique
|
||||
cluster_centers = sorted_centers[unique]
|
||||
|
||||
# ASSIGN LABELS: a point belongs to the cluster that it is closest to
|
||||
nbrs = NearestNeighbors(n_neighbors=1, n_jobs=self.n_jobs).fit(cluster_centers)
|
||||
labels = np.zeros(n_samples, dtype=int)
|
||||
distances, idxs = nbrs.kneighbors(X)
|
||||
if self.cluster_all:
|
||||
labels = idxs.flatten()
|
||||
else:
|
||||
labels.fill(-1)
|
||||
bool_selector = distances.flatten() <= bandwidth
|
||||
labels[bool_selector] = idxs.flatten()[bool_selector]
|
||||
|
||||
self.cluster_centers_, self.labels_ = cluster_centers, labels
|
||||
return self
|
||||
|
||||
def predict(self, X):
|
||||
"""Predict the closest cluster each sample in X belongs to.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
X : array-like of shape (n_samples, n_features)
|
||||
New data to predict.
|
||||
|
||||
Returns
|
||||
-------
|
||||
labels : ndarray of shape (n_samples,)
|
||||
Index of the cluster each sample belongs to.
|
||||
"""
|
||||
check_is_fitted(self)
|
||||
X = self._validate_data(X, reset=False)
|
||||
with config_context(assume_finite=True):
|
||||
return pairwise_distances_argmin(X, self.cluster_centers_)
|
||||
File diff suppressed because it is too large
Load Diff
@@ -0,0 +1,781 @@
|
||||
"""Algorithms for spectral clustering"""
|
||||
|
||||
# Author: Gael Varoquaux <gael.varoquaux@normalesup.org>
|
||||
# Brian Cheung
|
||||
# Wei LI <kuantkid@gmail.com>
|
||||
# Andrew Knyazev <Andrew.Knyazev@ucdenver.edu>
|
||||
# License: BSD 3 clause
|
||||
|
||||
import numbers
|
||||
import warnings
|
||||
|
||||
import numpy as np
|
||||
|
||||
from scipy.linalg import LinAlgError, qr, svd
|
||||
from scipy.sparse import csc_matrix
|
||||
|
||||
from ..base import BaseEstimator, ClusterMixin
|
||||
from ..utils import check_random_state, as_float_array, check_scalar
|
||||
from ..metrics.pairwise import pairwise_kernels
|
||||
from ..neighbors import kneighbors_graph, NearestNeighbors
|
||||
from ..manifold import spectral_embedding
|
||||
from ._kmeans import k_means
|
||||
|
||||
|
||||
def cluster_qr(vectors):
|
||||
"""Find the discrete partition closest to the eigenvector embedding.
|
||||
|
||||
This implementation was proposed in [1]_.
|
||||
|
||||
.. versionadded:: 1.1
|
||||
|
||||
Parameters
|
||||
----------
|
||||
vectors : array-like, shape: (n_samples, n_clusters)
|
||||
The embedding space of the samples.
|
||||
|
||||
Returns
|
||||
-------
|
||||
labels : array of integers, shape: n_samples
|
||||
The cluster labels of vectors.
|
||||
|
||||
References
|
||||
----------
|
||||
.. [1] :doi:`Simple, direct, and efficient multi-way spectral clustering, 2019
|
||||
Anil Damle, Victor Minden, Lexing Ying
|
||||
<10.1093/imaiai/iay008>`
|
||||
|
||||
"""
|
||||
|
||||
k = vectors.shape[1]
|
||||
_, _, piv = qr(vectors.T, pivoting=True)
|
||||
ut, _, v = svd(vectors[piv[:k], :].T)
|
||||
vectors = abs(np.dot(vectors, np.dot(ut, v.conj())))
|
||||
return vectors.argmax(axis=1)
|
||||
|
||||
|
||||
def discretize(
|
||||
vectors, *, copy=True, max_svd_restarts=30, n_iter_max=20, random_state=None
|
||||
):
|
||||
"""Search for a partition matrix which is closest to the eigenvector embedding.
|
||||
|
||||
This implementation was proposed in [1]_.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
vectors : array-like of shape (n_samples, n_clusters)
|
||||
The embedding space of the samples.
|
||||
|
||||
copy : bool, default=True
|
||||
Whether to copy vectors, or perform in-place normalization.
|
||||
|
||||
max_svd_restarts : int, default=30
|
||||
Maximum number of attempts to restart SVD if convergence fails
|
||||
|
||||
n_iter_max : int, default=30
|
||||
Maximum number of iterations to attempt in rotation and partition
|
||||
matrix search if machine precision convergence is not reached
|
||||
|
||||
random_state : int, RandomState instance, default=None
|
||||
Determines random number generation for rotation matrix initialization.
|
||||
Use an int to make the randomness deterministic.
|
||||
See :term:`Glossary <random_state>`.
|
||||
|
||||
Returns
|
||||
-------
|
||||
labels : array of integers, shape: n_samples
|
||||
The labels of the clusters.
|
||||
|
||||
References
|
||||
----------
|
||||
|
||||
.. [1] `Multiclass spectral clustering, 2003
|
||||
Stella X. Yu, Jianbo Shi
|
||||
<https://www1.icsi.berkeley.edu/~stellayu/publication/doc/2003kwayICCV.pdf>`_
|
||||
|
||||
Notes
|
||||
-----
|
||||
|
||||
The eigenvector embedding is used to iteratively search for the
|
||||
closest discrete partition. First, the eigenvector embedding is
|
||||
normalized to the space of partition matrices. An optimal discrete
|
||||
partition matrix closest to this normalized embedding multiplied by
|
||||
an initial rotation is calculated. Fixing this discrete partition
|
||||
matrix, an optimal rotation matrix is calculated. These two
|
||||
calculations are performed until convergence. The discrete partition
|
||||
matrix is returned as the clustering solution. Used in spectral
|
||||
clustering, this method tends to be faster and more robust to random
|
||||
initialization than k-means.
|
||||
|
||||
"""
|
||||
|
||||
random_state = check_random_state(random_state)
|
||||
|
||||
vectors = as_float_array(vectors, copy=copy)
|
||||
|
||||
eps = np.finfo(float).eps
|
||||
n_samples, n_components = vectors.shape
|
||||
|
||||
# Normalize the eigenvectors to an equal length of a vector of ones.
|
||||
# Reorient the eigenvectors to point in the negative direction with respect
|
||||
# to the first element. This may have to do with constraining the
|
||||
# eigenvectors to lie in a specific quadrant to make the discretization
|
||||
# search easier.
|
||||
norm_ones = np.sqrt(n_samples)
|
||||
for i in range(vectors.shape[1]):
|
||||
vectors[:, i] = (vectors[:, i] / np.linalg.norm(vectors[:, i])) * norm_ones
|
||||
if vectors[0, i] != 0:
|
||||
vectors[:, i] = -1 * vectors[:, i] * np.sign(vectors[0, i])
|
||||
|
||||
# Normalize the rows of the eigenvectors. Samples should lie on the unit
|
||||
# hypersphere centered at the origin. This transforms the samples in the
|
||||
# embedding space to the space of partition matrices.
|
||||
vectors = vectors / np.sqrt((vectors**2).sum(axis=1))[:, np.newaxis]
|
||||
|
||||
svd_restarts = 0
|
||||
has_converged = False
|
||||
|
||||
# If there is an exception we try to randomize and rerun SVD again
|
||||
# do this max_svd_restarts times.
|
||||
while (svd_restarts < max_svd_restarts) and not has_converged:
|
||||
|
||||
# Initialize first column of rotation matrix with a row of the
|
||||
# eigenvectors
|
||||
rotation = np.zeros((n_components, n_components))
|
||||
rotation[:, 0] = vectors[random_state.randint(n_samples), :].T
|
||||
|
||||
# To initialize the rest of the rotation matrix, find the rows
|
||||
# of the eigenvectors that are as orthogonal to each other as
|
||||
# possible
|
||||
c = np.zeros(n_samples)
|
||||
for j in range(1, n_components):
|
||||
# Accumulate c to ensure row is as orthogonal as possible to
|
||||
# previous picks as well as current one
|
||||
c += np.abs(np.dot(vectors, rotation[:, j - 1]))
|
||||
rotation[:, j] = vectors[c.argmin(), :].T
|
||||
|
||||
last_objective_value = 0.0
|
||||
n_iter = 0
|
||||
|
||||
while not has_converged:
|
||||
n_iter += 1
|
||||
|
||||
t_discrete = np.dot(vectors, rotation)
|
||||
|
||||
labels = t_discrete.argmax(axis=1)
|
||||
vectors_discrete = csc_matrix(
|
||||
(np.ones(len(labels)), (np.arange(0, n_samples), labels)),
|
||||
shape=(n_samples, n_components),
|
||||
)
|
||||
|
||||
t_svd = vectors_discrete.T * vectors
|
||||
|
||||
try:
|
||||
U, S, Vh = np.linalg.svd(t_svd)
|
||||
except LinAlgError:
|
||||
svd_restarts += 1
|
||||
print("SVD did not converge, randomizing and trying again")
|
||||
break
|
||||
|
||||
ncut_value = 2.0 * (n_samples - S.sum())
|
||||
if (abs(ncut_value - last_objective_value) < eps) or (n_iter > n_iter_max):
|
||||
has_converged = True
|
||||
else:
|
||||
# otherwise calculate rotation and continue
|
||||
last_objective_value = ncut_value
|
||||
rotation = np.dot(Vh.T, U.T)
|
||||
|
||||
if not has_converged:
|
||||
raise LinAlgError("SVD did not converge")
|
||||
return labels
|
||||
|
||||
|
||||
def spectral_clustering(
|
||||
affinity,
|
||||
*,
|
||||
n_clusters=8,
|
||||
n_components=None,
|
||||
eigen_solver=None,
|
||||
random_state=None,
|
||||
n_init=10,
|
||||
eigen_tol=0.0,
|
||||
assign_labels="kmeans",
|
||||
verbose=False,
|
||||
):
|
||||
"""Apply clustering to a projection of the normalized Laplacian.
|
||||
|
||||
In practice Spectral Clustering is very useful when the structure of
|
||||
the individual clusters is highly non-convex or more generally when
|
||||
a measure of the center and spread of the cluster is not a suitable
|
||||
description of the complete cluster. For instance, when clusters are
|
||||
nested circles on the 2D plane.
|
||||
|
||||
If affinity is the adjacency matrix of a graph, this method can be
|
||||
used to find normalized graph cuts [1]_, [2]_.
|
||||
|
||||
Read more in the :ref:`User Guide <spectral_clustering>`.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
affinity : {array-like, sparse matrix} of shape (n_samples, n_samples)
|
||||
The affinity matrix describing the relationship of the samples to
|
||||
embed. **Must be symmetric**.
|
||||
|
||||
Possible examples:
|
||||
- adjacency matrix of a graph,
|
||||
- heat kernel of the pairwise distance matrix of the samples,
|
||||
- symmetric k-nearest neighbours connectivity matrix of the samples.
|
||||
|
||||
n_clusters : int, default=None
|
||||
Number of clusters to extract.
|
||||
|
||||
n_components : int, default=n_clusters
|
||||
Number of eigenvectors to use for the spectral embedding.
|
||||
|
||||
eigen_solver : {None, 'arpack', 'lobpcg', or 'amg'}
|
||||
The eigenvalue decomposition method. If None then ``'arpack'`` is used.
|
||||
See [4]_ for more details regarding ``'lobpcg'``.
|
||||
Eigensolver ``'amg'`` runs ``'lobpcg'`` with optional
|
||||
Algebraic MultiGrid preconditioning and requires pyamg to be installed.
|
||||
It can be faster on very large sparse problems [6]_ and [7]_.
|
||||
|
||||
random_state : int, RandomState instance, default=None
|
||||
A pseudo random number generator used for the initialization
|
||||
of the lobpcg eigenvectors decomposition when `eigen_solver ==
|
||||
'amg'`, and for the K-Means initialization. Use an int to make
|
||||
the results deterministic across calls (See
|
||||
:term:`Glossary <random_state>`).
|
||||
|
||||
.. note::
|
||||
When using `eigen_solver == 'amg'`,
|
||||
it is necessary to also fix the global numpy seed with
|
||||
`np.random.seed(int)` to get deterministic results. See
|
||||
https://github.com/pyamg/pyamg/issues/139 for further
|
||||
information.
|
||||
|
||||
n_init : int, default=10
|
||||
Number of time the k-means algorithm will be run with different
|
||||
centroid seeds. The final results will be the best output of n_init
|
||||
consecutive runs in terms of inertia. Only used if
|
||||
``assign_labels='kmeans'``.
|
||||
|
||||
eigen_tol : float, default=0.0
|
||||
Stopping criterion for eigendecomposition of the Laplacian matrix
|
||||
when using arpack eigen_solver.
|
||||
|
||||
assign_labels : {'kmeans', 'discretize', 'cluster_qr'}, default='kmeans'
|
||||
The strategy to use to assign labels in the embedding
|
||||
space. There are three ways to assign labels after the Laplacian
|
||||
embedding. k-means can be applied and is a popular choice. But it can
|
||||
also be sensitive to initialization. Discretization is another
|
||||
approach which is less sensitive to random initialization [3]_.
|
||||
The cluster_qr method [5]_ directly extracts clusters from eigenvectors
|
||||
in spectral clustering. In contrast to k-means and discretization, cluster_qr
|
||||
has no tuning parameters and is not an iterative method, yet may outperform
|
||||
k-means and discretization in terms of both quality and speed.
|
||||
|
||||
.. versionchanged:: 1.1
|
||||
Added new labeling method 'cluster_qr'.
|
||||
|
||||
verbose : bool, default=False
|
||||
Verbosity mode.
|
||||
|
||||
.. versionadded:: 0.24
|
||||
|
||||
Returns
|
||||
-------
|
||||
labels : array of integers, shape: n_samples
|
||||
The labels of the clusters.
|
||||
|
||||
Notes
|
||||
-----
|
||||
The graph should contain only one connected component, elsewhere
|
||||
the results make little sense.
|
||||
|
||||
This algorithm solves the normalized cut for `k=2`: it is a
|
||||
normalized spectral clustering.
|
||||
|
||||
References
|
||||
----------
|
||||
|
||||
.. [1] :doi:`Normalized cuts and image segmentation, 2000
|
||||
Jianbo Shi, Jitendra Malik
|
||||
<10.1109/34.868688>`
|
||||
|
||||
.. [2] :doi:`A Tutorial on Spectral Clustering, 2007
|
||||
Ulrike von Luxburg
|
||||
<10.1007/s11222-007-9033-z>`
|
||||
|
||||
.. [3] `Multiclass spectral clustering, 2003
|
||||
Stella X. Yu, Jianbo Shi
|
||||
<https://www1.icsi.berkeley.edu/~stellayu/publication/doc/2003kwayICCV.pdf>`_
|
||||
|
||||
.. [4] :doi:`Toward the Optimal Preconditioned Eigensolver:
|
||||
Locally Optimal Block Preconditioned Conjugate Gradient Method, 2001
|
||||
A. V. Knyazev
|
||||
SIAM Journal on Scientific Computing 23, no. 2, pp. 517-541.
|
||||
<10.1137/S1064827500366124>`
|
||||
|
||||
.. [5] :doi:`Simple, direct, and efficient multi-way spectral clustering, 2019
|
||||
Anil Damle, Victor Minden, Lexing Ying
|
||||
<10.1093/imaiai/iay008>`
|
||||
|
||||
.. [6] :doi:`Multiscale Spectral Image Segmentation Multiscale preconditioning
|
||||
for computing eigenvalues of graph Laplacians in image segmentation, 2006
|
||||
Andrew Knyazev
|
||||
<10.13140/RG.2.2.35280.02565>`
|
||||
|
||||
.. [7] :doi:`Preconditioned spectral clustering for stochastic block partition
|
||||
streaming graph challenge (Preliminary version at arXiv.)
|
||||
David Zhuzhunashvili, Andrew Knyazev
|
||||
<10.1109/HPEC.2017.8091045>`
|
||||
"""
|
||||
if assign_labels not in ("kmeans", "discretize", "cluster_qr"):
|
||||
raise ValueError(
|
||||
"The 'assign_labels' parameter should be "
|
||||
"'kmeans' or 'discretize', or 'cluster_qr', "
|
||||
f"but {assign_labels!r} was given"
|
||||
)
|
||||
if isinstance(affinity, np.matrix):
|
||||
raise TypeError(
|
||||
"spectral_clustering does not support passing in affinity as an "
|
||||
"np.matrix. Please convert to a numpy array with np.asarray. For "
|
||||
"more information see: "
|
||||
"https://numpy.org/doc/stable/reference/generated/numpy.matrix.html", # noqa
|
||||
)
|
||||
|
||||
random_state = check_random_state(random_state)
|
||||
n_components = n_clusters if n_components is None else n_components
|
||||
|
||||
# We now obtain the real valued solution matrix to the
|
||||
# relaxed Ncut problem, solving the eigenvalue problem
|
||||
# L_sym x = lambda x and recovering u = D^-1/2 x.
|
||||
# The first eigenvector is constant only for fully connected graphs
|
||||
# and should be kept for spectral clustering (drop_first = False)
|
||||
# See spectral_embedding documentation.
|
||||
maps = spectral_embedding(
|
||||
affinity,
|
||||
n_components=n_components,
|
||||
eigen_solver=eigen_solver,
|
||||
random_state=random_state,
|
||||
eigen_tol=eigen_tol,
|
||||
drop_first=False,
|
||||
)
|
||||
if verbose:
|
||||
print(f"Computing label assignment using {assign_labels}")
|
||||
|
||||
if assign_labels == "kmeans":
|
||||
_, labels, _ = k_means(
|
||||
maps, n_clusters, random_state=random_state, n_init=n_init, verbose=verbose
|
||||
)
|
||||
elif assign_labels == "cluster_qr":
|
||||
labels = cluster_qr(maps)
|
||||
else:
|
||||
labels = discretize(maps, random_state=random_state)
|
||||
|
||||
return labels
|
||||
|
||||
|
||||
class SpectralClustering(ClusterMixin, BaseEstimator):
|
||||
"""Apply clustering to a projection of the normalized Laplacian.
|
||||
|
||||
In practice Spectral Clustering is very useful when the structure of
|
||||
the individual clusters is highly non-convex, or more generally when
|
||||
a measure of the center and spread of the cluster is not a suitable
|
||||
description of the complete cluster, such as when clusters are
|
||||
nested circles on the 2D plane.
|
||||
|
||||
If the affinity matrix is the adjacency matrix of a graph, this method
|
||||
can be used to find normalized graph cuts [1]_, [2]_.
|
||||
|
||||
When calling ``fit``, an affinity matrix is constructed using either
|
||||
a kernel function such the Gaussian (aka RBF) kernel with Euclidean
|
||||
distance ``d(X, X)``::
|
||||
|
||||
np.exp(-gamma * d(X,X) ** 2)
|
||||
|
||||
or a k-nearest neighbors connectivity matrix.
|
||||
|
||||
Alternatively, a user-provided affinity matrix can be specified by
|
||||
setting ``affinity='precomputed'``.
|
||||
|
||||
Read more in the :ref:`User Guide <spectral_clustering>`.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
n_clusters : int, default=8
|
||||
The dimension of the projection subspace.
|
||||
|
||||
eigen_solver : {'arpack', 'lobpcg', 'amg'}, default=None
|
||||
The eigenvalue decomposition strategy to use. AMG requires pyamg
|
||||
to be installed. It can be faster on very large, sparse problems,
|
||||
but may also lead to instabilities. If None, then ``'arpack'`` is
|
||||
used. See [4]_ for more details regarding `'lobpcg'`.
|
||||
|
||||
n_components : int, default=n_clusters
|
||||
Number of eigenvectors to use for the spectral embedding.
|
||||
|
||||
random_state : int, RandomState instance, default=None
|
||||
A pseudo random number generator used for the initialization
|
||||
of the lobpcg eigenvectors decomposition when `eigen_solver ==
|
||||
'amg'`, and for the K-Means initialization. Use an int to make
|
||||
the results deterministic across calls (See
|
||||
:term:`Glossary <random_state>`).
|
||||
|
||||
.. note::
|
||||
When using `eigen_solver == 'amg'`,
|
||||
it is necessary to also fix the global numpy seed with
|
||||
`np.random.seed(int)` to get deterministic results. See
|
||||
https://github.com/pyamg/pyamg/issues/139 for further
|
||||
information.
|
||||
|
||||
n_init : int, default=10
|
||||
Number of time the k-means algorithm will be run with different
|
||||
centroid seeds. The final results will be the best output of n_init
|
||||
consecutive runs in terms of inertia. Only used if
|
||||
``assign_labels='kmeans'``.
|
||||
|
||||
gamma : float, default=1.0
|
||||
Kernel coefficient for rbf, poly, sigmoid, laplacian and chi2 kernels.
|
||||
Ignored for ``affinity='nearest_neighbors'``.
|
||||
|
||||
affinity : str or callable, default='rbf'
|
||||
How to construct the affinity matrix.
|
||||
- 'nearest_neighbors': construct the affinity matrix by computing a
|
||||
graph of nearest neighbors.
|
||||
- 'rbf': construct the affinity matrix using a radial basis function
|
||||
(RBF) kernel.
|
||||
- 'precomputed': interpret ``X`` as a precomputed affinity matrix,
|
||||
where larger values indicate greater similarity between instances.
|
||||
- 'precomputed_nearest_neighbors': interpret ``X`` as a sparse graph
|
||||
of precomputed distances, and construct a binary affinity matrix
|
||||
from the ``n_neighbors`` nearest neighbors of each instance.
|
||||
- one of the kernels supported by
|
||||
:func:`~sklearn.metrics.pairwise_kernels`.
|
||||
|
||||
Only kernels that produce similarity scores (non-negative values that
|
||||
increase with similarity) should be used. This property is not checked
|
||||
by the clustering algorithm.
|
||||
|
||||
n_neighbors : int, default=10
|
||||
Number of neighbors to use when constructing the affinity matrix using
|
||||
the nearest neighbors method. Ignored for ``affinity='rbf'``.
|
||||
|
||||
eigen_tol : float, default=0.0
|
||||
Stopping criterion for eigendecomposition of the Laplacian matrix
|
||||
when ``eigen_solver='arpack'``.
|
||||
|
||||
assign_labels : {'kmeans', 'discretize', 'cluster_qr'}, default='kmeans'
|
||||
The strategy for assigning labels in the embedding space. There are two
|
||||
ways to assign labels after the Laplacian embedding. k-means is a
|
||||
popular choice, but it can be sensitive to initialization.
|
||||
Discretization is another approach which is less sensitive to random
|
||||
initialization [3]_.
|
||||
The cluster_qr method [5]_ directly extract clusters from eigenvectors
|
||||
in spectral clustering. In contrast to k-means and discretization, cluster_qr
|
||||
has no tuning parameters and runs no iterations, yet may outperform
|
||||
k-means and discretization in terms of both quality and speed.
|
||||
|
||||
.. versionchanged:: 1.1
|
||||
Added new labeling method 'cluster_qr'.
|
||||
|
||||
degree : float, default=3
|
||||
Degree of the polynomial kernel. Ignored by other kernels.
|
||||
|
||||
coef0 : float, default=1
|
||||
Zero coefficient for polynomial and sigmoid kernels.
|
||||
Ignored by other kernels.
|
||||
|
||||
kernel_params : dict of str to any, default=None
|
||||
Parameters (keyword arguments) and values for kernel passed as
|
||||
callable object. Ignored by other kernels.
|
||||
|
||||
n_jobs : int, default=None
|
||||
The number of parallel jobs to run when `affinity='nearest_neighbors'`
|
||||
or `affinity='precomputed_nearest_neighbors'`. The neighbors search
|
||||
will be done in parallel.
|
||||
``None`` means 1 unless in a :obj:`joblib.parallel_backend` context.
|
||||
``-1`` means using all processors. See :term:`Glossary <n_jobs>`
|
||||
for more details.
|
||||
|
||||
verbose : bool, default=False
|
||||
Verbosity mode.
|
||||
|
||||
.. versionadded:: 0.24
|
||||
|
||||
Attributes
|
||||
----------
|
||||
affinity_matrix_ : array-like of shape (n_samples, n_samples)
|
||||
Affinity matrix used for clustering. Available only after calling
|
||||
``fit``.
|
||||
|
||||
labels_ : ndarray of shape (n_samples,)
|
||||
Labels of each point
|
||||
|
||||
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
|
||||
--------
|
||||
sklearn.cluster.KMeans : K-Means clustering.
|
||||
sklearn.cluster.DBSCAN : Density-Based Spatial Clustering of
|
||||
Applications with Noise.
|
||||
|
||||
Notes
|
||||
-----
|
||||
A distance matrix for which 0 indicates identical elements and high values
|
||||
indicate very dissimilar elements can be transformed into an affinity /
|
||||
similarity matrix that is well-suited for the algorithm by
|
||||
applying the Gaussian (aka RBF, heat) kernel::
|
||||
|
||||
np.exp(- dist_matrix ** 2 / (2. * delta ** 2))
|
||||
|
||||
where ``delta`` is a free parameter representing the width of the Gaussian
|
||||
kernel.
|
||||
|
||||
An alternative is to take a symmetric version of the k-nearest neighbors
|
||||
connectivity matrix of the points.
|
||||
|
||||
If the pyamg package is installed, it is used: this greatly
|
||||
speeds up computation.
|
||||
|
||||
References
|
||||
----------
|
||||
.. [1] :doi:`Normalized cuts and image segmentation, 2000
|
||||
Jianbo Shi, Jitendra Malik
|
||||
<10.1109/34.868688>`
|
||||
|
||||
.. [2] :doi:`A Tutorial on Spectral Clustering, 2007
|
||||
Ulrike von Luxburg
|
||||
<10.1007/s11222-007-9033-z>`
|
||||
|
||||
.. [3] `Multiclass spectral clustering, 2003
|
||||
Stella X. Yu, Jianbo Shi
|
||||
<https://www1.icsi.berkeley.edu/~stellayu/publication/doc/2003kwayICCV.pdf>`_
|
||||
|
||||
.. [4] `Toward the Optimal Preconditioned Eigensolver:
|
||||
Locally Optimal Block Preconditioned Conjugate Gradient Method, 2001.
|
||||
A. V. Knyazev
|
||||
SIAM Journal on Scientific Computing 23, no. 2, pp. 517-541.
|
||||
<https://epubs.siam.org/doi/pdf/10.1137/S1064827500366124>`_
|
||||
|
||||
.. [5] :doi:`Simple, direct, and efficient multi-way spectral clustering, 2019
|
||||
Anil Damle, Victor Minden, Lexing Ying
|
||||
<10.1093/imaiai/iay008>`
|
||||
|
||||
Examples
|
||||
--------
|
||||
>>> from sklearn.cluster import SpectralClustering
|
||||
>>> import numpy as np
|
||||
>>> X = np.array([[1, 1], [2, 1], [1, 0],
|
||||
... [4, 7], [3, 5], [3, 6]])
|
||||
>>> clustering = SpectralClustering(n_clusters=2,
|
||||
... assign_labels='discretize',
|
||||
... random_state=0).fit(X)
|
||||
>>> clustering.labels_
|
||||
array([1, 1, 1, 0, 0, 0])
|
||||
>>> clustering
|
||||
SpectralClustering(assign_labels='discretize', n_clusters=2,
|
||||
random_state=0)
|
||||
"""
|
||||
|
||||
def __init__(
|
||||
self,
|
||||
n_clusters=8,
|
||||
*,
|
||||
eigen_solver=None,
|
||||
n_components=None,
|
||||
random_state=None,
|
||||
n_init=10,
|
||||
gamma=1.0,
|
||||
affinity="rbf",
|
||||
n_neighbors=10,
|
||||
eigen_tol=0.0,
|
||||
assign_labels="kmeans",
|
||||
degree=3,
|
||||
coef0=1,
|
||||
kernel_params=None,
|
||||
n_jobs=None,
|
||||
verbose=False,
|
||||
):
|
||||
self.n_clusters = n_clusters
|
||||
self.eigen_solver = eigen_solver
|
||||
self.n_components = n_components
|
||||
self.random_state = random_state
|
||||
self.n_init = n_init
|
||||
self.gamma = gamma
|
||||
self.affinity = affinity
|
||||
self.n_neighbors = n_neighbors
|
||||
self.eigen_tol = eigen_tol
|
||||
self.assign_labels = assign_labels
|
||||
self.degree = degree
|
||||
self.coef0 = coef0
|
||||
self.kernel_params = kernel_params
|
||||
self.n_jobs = n_jobs
|
||||
self.verbose = verbose
|
||||
|
||||
def fit(self, X, y=None):
|
||||
"""Perform spectral clustering from features, or affinity matrix.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
X : {array-like, sparse matrix} of shape (n_samples, n_features) or \
|
||||
(n_samples, n_samples)
|
||||
Training instances to cluster, similarities / affinities between
|
||||
instances if ``affinity='precomputed'``, or distances between
|
||||
instances if ``affinity='precomputed_nearest_neighbors``. If a
|
||||
sparse matrix is provided in a format other than ``csr_matrix``,
|
||||
``csc_matrix``, or ``coo_matrix``, it will be converted into a
|
||||
sparse ``csr_matrix``.
|
||||
|
||||
y : Ignored
|
||||
Not used, present here for API consistency by convention.
|
||||
|
||||
Returns
|
||||
-------
|
||||
self : object
|
||||
A fitted instance of the estimator.
|
||||
"""
|
||||
X = self._validate_data(
|
||||
X,
|
||||
accept_sparse=["csr", "csc", "coo"],
|
||||
dtype=np.float64,
|
||||
ensure_min_samples=2,
|
||||
)
|
||||
allow_squared = self.affinity in [
|
||||
"precomputed",
|
||||
"precomputed_nearest_neighbors",
|
||||
]
|
||||
if X.shape[0] == X.shape[1] and not allow_squared:
|
||||
warnings.warn(
|
||||
"The spectral clustering API has changed. ``fit``"
|
||||
"now constructs an affinity matrix from data. To use"
|
||||
" a custom affinity matrix, "
|
||||
"set ``affinity=precomputed``."
|
||||
)
|
||||
|
||||
check_scalar(
|
||||
self.n_clusters,
|
||||
"n_clusters",
|
||||
target_type=numbers.Integral,
|
||||
min_val=1,
|
||||
include_boundaries="left",
|
||||
)
|
||||
|
||||
check_scalar(
|
||||
self.n_init,
|
||||
"n_init",
|
||||
target_type=numbers.Integral,
|
||||
min_val=1,
|
||||
include_boundaries="left",
|
||||
)
|
||||
|
||||
check_scalar(
|
||||
self.gamma,
|
||||
"gamma",
|
||||
target_type=numbers.Real,
|
||||
min_val=1.0,
|
||||
include_boundaries="left",
|
||||
)
|
||||
|
||||
check_scalar(
|
||||
self.n_neighbors,
|
||||
"n_neighbors",
|
||||
target_type=numbers.Integral,
|
||||
min_val=1,
|
||||
include_boundaries="left",
|
||||
)
|
||||
|
||||
if self.eigen_solver == "arpack":
|
||||
check_scalar(
|
||||
self.eigen_tol,
|
||||
"eigen_tol",
|
||||
target_type=numbers.Real,
|
||||
min_val=0,
|
||||
include_boundaries="left",
|
||||
)
|
||||
|
||||
check_scalar(
|
||||
self.degree,
|
||||
"degree",
|
||||
target_type=numbers.Integral,
|
||||
min_val=1,
|
||||
include_boundaries="left",
|
||||
)
|
||||
|
||||
if self.affinity == "nearest_neighbors":
|
||||
connectivity = kneighbors_graph(
|
||||
X, n_neighbors=self.n_neighbors, include_self=True, n_jobs=self.n_jobs
|
||||
)
|
||||
self.affinity_matrix_ = 0.5 * (connectivity + connectivity.T)
|
||||
elif self.affinity == "precomputed_nearest_neighbors":
|
||||
estimator = NearestNeighbors(
|
||||
n_neighbors=self.n_neighbors, n_jobs=self.n_jobs, metric="precomputed"
|
||||
).fit(X)
|
||||
connectivity = estimator.kneighbors_graph(X=X, mode="connectivity")
|
||||
self.affinity_matrix_ = 0.5 * (connectivity + connectivity.T)
|
||||
elif self.affinity == "precomputed":
|
||||
self.affinity_matrix_ = X
|
||||
else:
|
||||
params = self.kernel_params
|
||||
if params is None:
|
||||
params = {}
|
||||
if not callable(self.affinity):
|
||||
params["gamma"] = self.gamma
|
||||
params["degree"] = self.degree
|
||||
params["coef0"] = self.coef0
|
||||
self.affinity_matrix_ = pairwise_kernels(
|
||||
X, metric=self.affinity, filter_params=True, **params
|
||||
)
|
||||
|
||||
random_state = check_random_state(self.random_state)
|
||||
self.labels_ = spectral_clustering(
|
||||
self.affinity_matrix_,
|
||||
n_clusters=self.n_clusters,
|
||||
n_components=self.n_components,
|
||||
eigen_solver=self.eigen_solver,
|
||||
random_state=random_state,
|
||||
n_init=self.n_init,
|
||||
eigen_tol=self.eigen_tol,
|
||||
assign_labels=self.assign_labels,
|
||||
verbose=self.verbose,
|
||||
)
|
||||
return self
|
||||
|
||||
def fit_predict(self, X, y=None):
|
||||
"""Perform spectral clustering on `X` and return cluster labels.
|
||||
|
||||
Parameters
|
||||
----------
|
||||
X : {array-like, sparse matrix} of shape (n_samples, n_features) or \
|
||||
(n_samples, n_samples)
|
||||
Training instances to cluster, similarities / affinities between
|
||||
instances if ``affinity='precomputed'``, or distances between
|
||||
instances if ``affinity='precomputed_nearest_neighbors``. If a
|
||||
sparse matrix is provided in a format other than ``csr_matrix``,
|
||||
``csc_matrix``, or ``coo_matrix``, it will be converted into a
|
||||
sparse ``csr_matrix``.
|
||||
|
||||
y : Ignored
|
||||
Not used, present here for API consistency by convention.
|
||||
|
||||
Returns
|
||||
-------
|
||||
labels : ndarray of shape (n_samples,)
|
||||
Cluster labels.
|
||||
"""
|
||||
return super().fit_predict(X, y)
|
||||
|
||||
def _more_tags(self):
|
||||
return {
|
||||
"pairwise": self.affinity
|
||||
in ["precomputed", "precomputed_nearest_neighbors"]
|
||||
}
|
||||
@@ -0,0 +1,68 @@
|
||||
# Author: Alexandre Gramfort <alexandre.gramfort@inria.fr>
|
||||
# License: BSD 3 clause
|
||||
import os
|
||||
|
||||
import numpy
|
||||
|
||||
|
||||
def configuration(parent_package="", top_path=None):
|
||||
from numpy.distutils.misc_util import Configuration
|
||||
|
||||
libraries = []
|
||||
if os.name == "posix":
|
||||
libraries.append("m")
|
||||
|
||||
config = Configuration("cluster", parent_package, top_path)
|
||||
|
||||
config.add_extension(
|
||||
"_dbscan_inner",
|
||||
sources=["_dbscan_inner.pyx"],
|
||||
include_dirs=[numpy.get_include()],
|
||||
language="c++",
|
||||
)
|
||||
|
||||
config.add_extension(
|
||||
"_hierarchical_fast",
|
||||
sources=["_hierarchical_fast.pyx"],
|
||||
language="c++",
|
||||
include_dirs=[numpy.get_include()],
|
||||
libraries=libraries,
|
||||
)
|
||||
|
||||
config.add_extension(
|
||||
"_k_means_common",
|
||||
sources=["_k_means_common.pyx"],
|
||||
include_dirs=[numpy.get_include()],
|
||||
libraries=libraries,
|
||||
)
|
||||
|
||||
config.add_extension(
|
||||
"_k_means_lloyd",
|
||||
sources=["_k_means_lloyd.pyx"],
|
||||
include_dirs=[numpy.get_include()],
|
||||
libraries=libraries,
|
||||
)
|
||||
|
||||
config.add_extension(
|
||||
"_k_means_elkan",
|
||||
sources=["_k_means_elkan.pyx"],
|
||||
include_dirs=[numpy.get_include()],
|
||||
libraries=libraries,
|
||||
)
|
||||
|
||||
config.add_extension(
|
||||
"_k_means_minibatch",
|
||||
sources=["_k_means_minibatch.pyx"],
|
||||
include_dirs=[numpy.get_include()],
|
||||
libraries=libraries,
|
||||
)
|
||||
|
||||
config.add_subpackage("tests")
|
||||
|
||||
return config
|
||||
|
||||
|
||||
if __name__ == "__main__":
|
||||
from numpy.distutils.core import setup
|
||||
|
||||
setup(**configuration(top_path="").todict())
|
||||
Binary file not shown.
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@@ -0,0 +1,38 @@
|
||||
"""
|
||||
Common utilities for testing clustering.
|
||||
|
||||
"""
|
||||
|
||||
import numpy as np
|
||||
|
||||
|
||||
###############################################################################
|
||||
# Generate sample data
|
||||
|
||||
|
||||
def generate_clustered_data(
|
||||
seed=0, n_clusters=3, n_features=2, n_samples_per_cluster=20, std=0.4
|
||||
):
|
||||
prng = np.random.RandomState(seed)
|
||||
|
||||
# the data is voluntary shifted away from zero to check clustering
|
||||
# algorithm robustness with regards to non centered data
|
||||
means = (
|
||||
np.array(
|
||||
[
|
||||
[1, 1, 1, 0],
|
||||
[-1, -1, 0, 1],
|
||||
[1, -1, 1, 1],
|
||||
[-1, 1, 1, 0],
|
||||
]
|
||||
)
|
||||
+ 10
|
||||
)
|
||||
|
||||
X = np.empty((0, n_features))
|
||||
for i in range(n_clusters):
|
||||
X = np.r_[
|
||||
X,
|
||||
means[i][:n_features] + std * prng.randn(n_samples_per_cluster, n_features),
|
||||
]
|
||||
return X
|
||||
@@ -0,0 +1,284 @@
|
||||
"""
|
||||
Testing for Clustering methods
|
||||
|
||||
"""
|
||||
|
||||
import numpy as np
|
||||
import pytest
|
||||
import warnings
|
||||
|
||||
from scipy.sparse import csr_matrix
|
||||
|
||||
from sklearn.exceptions import ConvergenceWarning
|
||||
from sklearn.utils._testing import assert_array_equal
|
||||
|
||||
from sklearn.cluster import AffinityPropagation
|
||||
from sklearn.cluster._affinity_propagation import _equal_similarities_and_preferences
|
||||
from sklearn.cluster import affinity_propagation
|
||||
from sklearn.datasets import make_blobs
|
||||
from sklearn.metrics import euclidean_distances
|
||||
|
||||
n_clusters = 3
|
||||
centers = np.array([[1, 1], [-1, -1], [1, -1]]) + 10
|
||||
X, _ = make_blobs(
|
||||
n_samples=60,
|
||||
n_features=2,
|
||||
centers=centers,
|
||||
cluster_std=0.4,
|
||||
shuffle=True,
|
||||
random_state=0,
|
||||
)
|
||||
|
||||
|
||||
def test_affinity_propagation():
|
||||
# Affinity Propagation algorithm
|
||||
# Compute similarities
|
||||
S = -euclidean_distances(X, squared=True)
|
||||
preference = np.median(S) * 10
|
||||
# Compute Affinity Propagation
|
||||
cluster_centers_indices, labels = affinity_propagation(
|
||||
S, preference=preference, random_state=39
|
||||
)
|
||||
|
||||
n_clusters_ = len(cluster_centers_indices)
|
||||
|
||||
assert n_clusters == n_clusters_
|
||||
|
||||
af = AffinityPropagation(
|
||||
preference=preference, affinity="precomputed", random_state=28
|
||||
)
|
||||
labels_precomputed = af.fit(S).labels_
|
||||
|
||||
af = AffinityPropagation(preference=preference, verbose=True, random_state=37)
|
||||
labels = af.fit(X).labels_
|
||||
|
||||
assert_array_equal(labels, labels_precomputed)
|
||||
|
||||
cluster_centers_indices = af.cluster_centers_indices_
|
||||
|
||||
n_clusters_ = len(cluster_centers_indices)
|
||||
assert np.unique(labels).size == n_clusters_
|
||||
assert n_clusters == n_clusters_
|
||||
|
||||
# Test also with no copy
|
||||
_, labels_no_copy = affinity_propagation(
|
||||
S, preference=preference, copy=False, random_state=74
|
||||
)
|
||||
assert_array_equal(labels, labels_no_copy)
|
||||
|
||||
|
||||
def test_affinity_propagation_affinity_shape():
|
||||
"""Check the shape of the affinity matrix when using `affinity_propagation."""
|
||||
S = -euclidean_distances(X, squared=True)
|
||||
err_msg = "S must be a square array"
|
||||
with pytest.raises(ValueError, match=err_msg):
|
||||
affinity_propagation(S[:, :-1])
|
||||
|
||||
|
||||
@pytest.mark.parametrize(
|
||||
"input, params, err_type, err_msg",
|
||||
[
|
||||
(X, {"damping": 0}, ValueError, "damping == 0, must be >= 0.5"),
|
||||
(X, {"damping": 2}, ValueError, "damping == 2, must be < 1"),
|
||||
(X, {"max_iter": 0}, ValueError, "max_iter == 0, must be >= 1."),
|
||||
(X, {"convergence_iter": 0}, ValueError, "convergence_iter == 0, must be >= 1"),
|
||||
(X, {"affinity": "unknown"}, ValueError, "Affinity must be"),
|
||||
(
|
||||
csr_matrix((3, 3)),
|
||||
{"affinity": "precomputed"},
|
||||
TypeError,
|
||||
"A sparse matrix was passed, but dense data is required",
|
||||
),
|
||||
],
|
||||
)
|
||||
def test_affinity_propagation_params_validation(input, params, err_type, err_msg):
|
||||
"""Check the parameters validation in `AffinityPropagation`."""
|
||||
with pytest.raises(err_type, match=err_msg):
|
||||
AffinityPropagation(**params).fit(input)
|
||||
|
||||
|
||||
def test_affinity_propagation_predict():
|
||||
# Test AffinityPropagation.predict
|
||||
af = AffinityPropagation(affinity="euclidean", random_state=63)
|
||||
labels = af.fit_predict(X)
|
||||
labels2 = af.predict(X)
|
||||
assert_array_equal(labels, labels2)
|
||||
|
||||
|
||||
def test_affinity_propagation_predict_error():
|
||||
# Test exception in AffinityPropagation.predict
|
||||
# Not fitted.
|
||||
af = AffinityPropagation(affinity="euclidean")
|
||||
with pytest.raises(ValueError):
|
||||
af.predict(X)
|
||||
|
||||
# Predict not supported when affinity="precomputed".
|
||||
S = np.dot(X, X.T)
|
||||
af = AffinityPropagation(affinity="precomputed", random_state=57)
|
||||
af.fit(S)
|
||||
with pytest.raises(ValueError):
|
||||
af.predict(X)
|
||||
|
||||
|
||||
def test_affinity_propagation_fit_non_convergence():
|
||||
# In case of non-convergence of affinity_propagation(), the cluster
|
||||
# centers should be an empty array and training samples should be labelled
|
||||
# as noise (-1)
|
||||
X = np.array([[0, 0], [1, 1], [-2, -2]])
|
||||
|
||||
# Force non-convergence by allowing only a single iteration
|
||||
af = AffinityPropagation(preference=-10, max_iter=1, random_state=82)
|
||||
|
||||
with pytest.warns(ConvergenceWarning):
|
||||
af.fit(X)
|
||||
assert_array_equal(np.empty((0, 2)), af.cluster_centers_)
|
||||
assert_array_equal(np.array([-1, -1, -1]), af.labels_)
|
||||
|
||||
|
||||
def test_affinity_propagation_equal_mutual_similarities():
|
||||
X = np.array([[-1, 1], [1, -1]])
|
||||
S = -euclidean_distances(X, squared=True)
|
||||
|
||||
# setting preference > similarity
|
||||
with pytest.warns(UserWarning, match="mutually equal"):
|
||||
cluster_center_indices, labels = affinity_propagation(S, preference=0)
|
||||
|
||||
# expect every sample to become an exemplar
|
||||
assert_array_equal([0, 1], cluster_center_indices)
|
||||
assert_array_equal([0, 1], labels)
|
||||
|
||||
# setting preference < similarity
|
||||
with pytest.warns(UserWarning, match="mutually equal"):
|
||||
cluster_center_indices, labels = affinity_propagation(S, preference=-10)
|
||||
|
||||
# expect one cluster, with arbitrary (first) sample as exemplar
|
||||
assert_array_equal([0], cluster_center_indices)
|
||||
assert_array_equal([0, 0], labels)
|
||||
|
||||
# setting different preferences
|
||||
with warnings.catch_warnings():
|
||||
warnings.simplefilter("error", UserWarning)
|
||||
cluster_center_indices, labels = affinity_propagation(
|
||||
S, preference=[-20, -10], random_state=37
|
||||
)
|
||||
|
||||
# expect one cluster, with highest-preference sample as exemplar
|
||||
assert_array_equal([1], cluster_center_indices)
|
||||
assert_array_equal([0, 0], labels)
|
||||
|
||||
|
||||
def test_affinity_propagation_predict_non_convergence():
|
||||
# In case of non-convergence of affinity_propagation(), the cluster
|
||||
# centers should be an empty array
|
||||
X = np.array([[0, 0], [1, 1], [-2, -2]])
|
||||
|
||||
# Force non-convergence by allowing only a single iteration
|
||||
with pytest.warns(ConvergenceWarning):
|
||||
af = AffinityPropagation(preference=-10, max_iter=1, random_state=75).fit(X)
|
||||
|
||||
# At prediction time, consider new samples as noise since there are no
|
||||
# clusters
|
||||
to_predict = np.array([[2, 2], [3, 3], [4, 4]])
|
||||
with pytest.warns(ConvergenceWarning):
|
||||
y = af.predict(to_predict)
|
||||
assert_array_equal(np.array([-1, -1, -1]), y)
|
||||
|
||||
|
||||
def test_affinity_propagation_non_convergence_regressiontest():
|
||||
X = np.array([[1, 0, 0, 0, 0, 0], [0, 1, 1, 1, 0, 0], [0, 0, 1, 0, 0, 1]])
|
||||
af = AffinityPropagation(affinity="euclidean", max_iter=2, random_state=34)
|
||||
msg = (
|
||||
"Affinity propagation did not converge, this model may return degenerate"
|
||||
" cluster centers and labels."
|
||||
)
|
||||
with pytest.warns(ConvergenceWarning, match=msg):
|
||||
af.fit(X)
|
||||
|
||||
assert_array_equal(np.array([0, 0, 0]), af.labels_)
|
||||
|
||||
|
||||
def test_equal_similarities_and_preferences():
|
||||
# Unequal distances
|
||||
X = np.array([[0, 0], [1, 1], [-2, -2]])
|
||||
S = -euclidean_distances(X, squared=True)
|
||||
|
||||
assert not _equal_similarities_and_preferences(S, np.array(0))
|
||||
assert not _equal_similarities_and_preferences(S, np.array([0, 0]))
|
||||
assert not _equal_similarities_and_preferences(S, np.array([0, 1]))
|
||||
|
||||
# Equal distances
|
||||
X = np.array([[0, 0], [1, 1]])
|
||||
S = -euclidean_distances(X, squared=True)
|
||||
|
||||
# Different preferences
|
||||
assert not _equal_similarities_and_preferences(S, np.array([0, 1]))
|
||||
|
||||
# Same preferences
|
||||
assert _equal_similarities_and_preferences(S, np.array([0, 0]))
|
||||
assert _equal_similarities_and_preferences(S, np.array(0))
|
||||
|
||||
|
||||
def test_affinity_propagation_random_state():
|
||||
# Significance of random_state parameter
|
||||
# Generate sample data
|
||||
centers = [[1, 1], [-1, -1], [1, -1]]
|
||||
X, labels_true = make_blobs(
|
||||
n_samples=300, centers=centers, cluster_std=0.5, random_state=0
|
||||
)
|
||||
# random_state = 0
|
||||
ap = AffinityPropagation(convergence_iter=1, max_iter=2, random_state=0)
|
||||
ap.fit(X)
|
||||
centers0 = ap.cluster_centers_
|
||||
|
||||
# random_state = 76
|
||||
ap = AffinityPropagation(convergence_iter=1, max_iter=2, random_state=76)
|
||||
ap.fit(X)
|
||||
centers76 = ap.cluster_centers_
|
||||
|
||||
assert np.mean((centers0 - centers76) ** 2) > 1
|
||||
|
||||
|
||||
@pytest.mark.parametrize("centers", [csr_matrix(np.zeros((1, 10))), np.zeros((1, 10))])
|
||||
def test_affinity_propagation_convergence_warning_dense_sparse(centers):
|
||||
"""Non-regression, see #13334"""
|
||||
rng = np.random.RandomState(42)
|
||||
X = rng.rand(40, 10)
|
||||
y = (4 * rng.rand(40)).astype(int)
|
||||
ap = AffinityPropagation(random_state=46)
|
||||
ap.fit(X, y)
|
||||
ap.cluster_centers_ = centers
|
||||
with warnings.catch_warnings():
|
||||
warnings.simplefilter("error", ConvergenceWarning)
|
||||
assert_array_equal(ap.predict(X), np.zeros(X.shape[0], dtype=int))
|
||||
|
||||
|
||||
def test_affinity_propagation_float32():
|
||||
# Test to fix incorrect clusters due to dtype change
|
||||
# (non-regression test for issue #10832)
|
||||
X = np.array(
|
||||
[[1, 0, 0, 0], [0, 1, 1, 0], [0, 1, 1, 0], [0, 0, 0, 1]], dtype="float32"
|
||||
)
|
||||
afp = AffinityPropagation(preference=1, affinity="precomputed", random_state=0).fit(
|
||||
X
|
||||
)
|
||||
expected = np.array([0, 1, 1, 2])
|
||||
assert_array_equal(afp.labels_, expected)
|
||||
|
||||
|
||||
def test_sparse_input_for_predict():
|
||||
# Test to make sure sparse inputs are accepted for predict
|
||||
# (non-regression test for issue #20049)
|
||||
af = AffinityPropagation(affinity="euclidean", random_state=42)
|
||||
af.fit(X)
|
||||
labels = af.predict(csr_matrix((2, 2)))
|
||||
assert_array_equal(labels, (2, 2))
|
||||
|
||||
|
||||
def test_sparse_input_for_fit_predict():
|
||||
# Test to make sure sparse inputs are accepted for fit_predict
|
||||
# (non-regression test for issue #20049)
|
||||
af = AffinityPropagation(affinity="euclidean", random_state=42)
|
||||
rng = np.random.RandomState(42)
|
||||
X = csr_matrix(rng.randint(0, 2, size=(5, 5)))
|
||||
labels = af.fit_predict(X)
|
||||
assert_array_equal(labels, (0, 1, 1, 2, 3))
|
||||
@@ -0,0 +1,280 @@
|
||||
"""Testing for Spectral Biclustering methods"""
|
||||
|
||||
import numpy as np
|
||||
import pytest
|
||||
from scipy.sparse import csr_matrix, issparse
|
||||
|
||||
from sklearn.model_selection import ParameterGrid
|
||||
|
||||
from sklearn.utils._testing import assert_almost_equal
|
||||
from sklearn.utils._testing import assert_array_equal
|
||||
from sklearn.utils._testing import assert_array_almost_equal
|
||||
|
||||
from sklearn.base import BaseEstimator, BiclusterMixin
|
||||
|
||||
from sklearn.cluster import SpectralCoclustering
|
||||
from sklearn.cluster import SpectralBiclustering
|
||||
from sklearn.cluster._bicluster import _scale_normalize
|
||||
from sklearn.cluster._bicluster import _bistochastic_normalize
|
||||
from sklearn.cluster._bicluster import _log_normalize
|
||||
|
||||
from sklearn.metrics import consensus_score, v_measure_score
|
||||
|
||||
from sklearn.datasets import make_biclusters, make_checkerboard
|
||||
|
||||
|
||||
class MockBiclustering(BiclusterMixin, BaseEstimator):
|
||||
# Mock object for testing get_submatrix.
|
||||
def __init__(self):
|
||||
pass
|
||||
|
||||
def get_indices(self, i):
|
||||
# Overridden to reproduce old get_submatrix test.
|
||||
return (
|
||||
np.where([True, True, False, False, True])[0],
|
||||
np.where([False, False, True, True])[0],
|
||||
)
|
||||
|
||||
|
||||
def test_get_submatrix():
|
||||
data = np.arange(20).reshape(5, 4)
|
||||
model = MockBiclustering()
|
||||
|
||||
for X in (data, csr_matrix(data), data.tolist()):
|
||||
submatrix = model.get_submatrix(0, X)
|
||||
if issparse(submatrix):
|
||||
submatrix = submatrix.toarray()
|
||||
assert_array_equal(submatrix, [[2, 3], [6, 7], [18, 19]])
|
||||
submatrix[:] = -1
|
||||
if issparse(X):
|
||||
X = X.toarray()
|
||||
assert np.all(X != -1)
|
||||
|
||||
|
||||
def _test_shape_indices(model):
|
||||
# Test get_shape and get_indices on fitted model.
|
||||
for i in range(model.n_clusters):
|
||||
m, n = model.get_shape(i)
|
||||
i_ind, j_ind = model.get_indices(i)
|
||||
assert len(i_ind) == m
|
||||
assert len(j_ind) == n
|
||||
|
||||
|
||||
def test_spectral_coclustering():
|
||||
# Test Dhillon's Spectral CoClustering on a simple problem.
|
||||
param_grid = {
|
||||
"svd_method": ["randomized", "arpack"],
|
||||
"n_svd_vecs": [None, 20],
|
||||
"mini_batch": [False, True],
|
||||
"init": ["k-means++"],
|
||||
"n_init": [10],
|
||||
}
|
||||
random_state = 0
|
||||
S, rows, cols = make_biclusters((30, 30), 3, noise=0.5, random_state=random_state)
|
||||
S -= S.min() # needs to be nonnegative before making it sparse
|
||||
S = np.where(S < 1, 0, S) # threshold some values
|
||||
for mat in (S, csr_matrix(S)):
|
||||
for kwargs in ParameterGrid(param_grid):
|
||||
model = SpectralCoclustering(
|
||||
n_clusters=3, random_state=random_state, **kwargs
|
||||
)
|
||||
model.fit(mat)
|
||||
|
||||
assert model.rows_.shape == (3, 30)
|
||||
assert_array_equal(model.rows_.sum(axis=0), np.ones(30))
|
||||
assert_array_equal(model.columns_.sum(axis=0), np.ones(30))
|
||||
assert consensus_score(model.biclusters_, (rows, cols)) == 1
|
||||
|
||||
_test_shape_indices(model)
|
||||
|
||||
|
||||
def test_spectral_biclustering():
|
||||
# Test Kluger methods on a checkerboard dataset.
|
||||
S, rows, cols = make_checkerboard((30, 30), 3, noise=0.5, random_state=0)
|
||||
|
||||
non_default_params = {
|
||||
"method": ["scale", "log"],
|
||||
"svd_method": ["arpack"],
|
||||
"n_svd_vecs": [20],
|
||||
"mini_batch": [True],
|
||||
}
|
||||
|
||||
for mat in (S, csr_matrix(S)):
|
||||
for param_name, param_values in non_default_params.items():
|
||||
for param_value in param_values:
|
||||
|
||||
model = SpectralBiclustering(
|
||||
n_clusters=3,
|
||||
n_init=3,
|
||||
init="k-means++",
|
||||
random_state=0,
|
||||
)
|
||||
model.set_params(**dict([(param_name, param_value)]))
|
||||
|
||||
if issparse(mat) and model.get_params().get("method") == "log":
|
||||
# cannot take log of sparse matrix
|
||||
with pytest.raises(ValueError):
|
||||
model.fit(mat)
|
||||
continue
|
||||
else:
|
||||
model.fit(mat)
|
||||
|
||||
assert model.rows_.shape == (9, 30)
|
||||
assert model.columns_.shape == (9, 30)
|
||||
assert_array_equal(model.rows_.sum(axis=0), np.repeat(3, 30))
|
||||
assert_array_equal(model.columns_.sum(axis=0), np.repeat(3, 30))
|
||||
assert consensus_score(model.biclusters_, (rows, cols)) == 1
|
||||
|
||||
_test_shape_indices(model)
|
||||
|
||||
|
||||
def _do_scale_test(scaled):
|
||||
"""Check that rows sum to one constant, and columns to another."""
|
||||
row_sum = scaled.sum(axis=1)
|
||||
col_sum = scaled.sum(axis=0)
|
||||
if issparse(scaled):
|
||||
row_sum = np.asarray(row_sum).squeeze()
|
||||
col_sum = np.asarray(col_sum).squeeze()
|
||||
assert_array_almost_equal(row_sum, np.tile(row_sum.mean(), 100), decimal=1)
|
||||
assert_array_almost_equal(col_sum, np.tile(col_sum.mean(), 100), decimal=1)
|
||||
|
||||
|
||||
def _do_bistochastic_test(scaled):
|
||||
"""Check that rows and columns sum to the same constant."""
|
||||
_do_scale_test(scaled)
|
||||
assert_almost_equal(scaled.sum(axis=0).mean(), scaled.sum(axis=1).mean(), decimal=1)
|
||||
|
||||
|
||||
def test_scale_normalize():
|
||||
generator = np.random.RandomState(0)
|
||||
X = generator.rand(100, 100)
|
||||
for mat in (X, csr_matrix(X)):
|
||||
scaled, _, _ = _scale_normalize(mat)
|
||||
_do_scale_test(scaled)
|
||||
if issparse(mat):
|
||||
assert issparse(scaled)
|
||||
|
||||
|
||||
def test_bistochastic_normalize():
|
||||
generator = np.random.RandomState(0)
|
||||
X = generator.rand(100, 100)
|
||||
for mat in (X, csr_matrix(X)):
|
||||
scaled = _bistochastic_normalize(mat)
|
||||
_do_bistochastic_test(scaled)
|
||||
if issparse(mat):
|
||||
assert issparse(scaled)
|
||||
|
||||
|
||||
def test_log_normalize():
|
||||
# adding any constant to a log-scaled matrix should make it
|
||||
# bistochastic
|
||||
generator = np.random.RandomState(0)
|
||||
mat = generator.rand(100, 100)
|
||||
scaled = _log_normalize(mat) + 1
|
||||
_do_bistochastic_test(scaled)
|
||||
|
||||
|
||||
def test_fit_best_piecewise():
|
||||
model = SpectralBiclustering(random_state=0)
|
||||
vectors = np.array([[0, 0, 0, 1, 1, 1], [2, 2, 2, 3, 3, 3], [0, 1, 2, 3, 4, 5]])
|
||||
best = model._fit_best_piecewise(vectors, n_best=2, n_clusters=2)
|
||||
assert_array_equal(best, vectors[:2])
|
||||
|
||||
|
||||
def test_project_and_cluster():
|
||||
model = SpectralBiclustering(random_state=0)
|
||||
data = np.array([[1, 1, 1], [1, 1, 1], [3, 6, 3], [3, 6, 3]])
|
||||
vectors = np.array([[1, 0], [0, 1], [0, 0]])
|
||||
for mat in (data, csr_matrix(data)):
|
||||
labels = model._project_and_cluster(mat, vectors, n_clusters=2)
|
||||
assert_almost_equal(v_measure_score(labels, [0, 0, 1, 1]), 1.0)
|
||||
|
||||
|
||||
def test_perfect_checkerboard():
|
||||
# XXX Previously failed on build bot (not reproducible)
|
||||
model = SpectralBiclustering(3, svd_method="arpack", random_state=0)
|
||||
|
||||
S, rows, cols = make_checkerboard((30, 30), 3, noise=0, random_state=0)
|
||||
model.fit(S)
|
||||
assert consensus_score(model.biclusters_, (rows, cols)) == 1
|
||||
|
||||
S, rows, cols = make_checkerboard((40, 30), 3, noise=0, random_state=0)
|
||||
model.fit(S)
|
||||
assert consensus_score(model.biclusters_, (rows, cols)) == 1
|
||||
|
||||
S, rows, cols = make_checkerboard((30, 40), 3, noise=0, random_state=0)
|
||||
model.fit(S)
|
||||
assert consensus_score(model.biclusters_, (rows, cols)) == 1
|
||||
|
||||
|
||||
@pytest.mark.parametrize(
|
||||
"params, type_err, err_msg",
|
||||
[
|
||||
({"n_init": 0}, ValueError, "n_init == 0, must be >= 1."),
|
||||
({"n_init": 1.5}, TypeError, "n_init must be an instance of"),
|
||||
(
|
||||
{"n_clusters": "abc"},
|
||||
TypeError,
|
||||
"n_clusters must be an instance of",
|
||||
),
|
||||
({"svd_method": "unknown"}, ValueError, "Unknown SVD method: 'unknown'"),
|
||||
],
|
||||
)
|
||||
def test_spectralcoclustering_parameter_validation(params, type_err, err_msg):
|
||||
"""Check parameters validation in `SpectralBiClustering`"""
|
||||
data = np.arange(25).reshape((5, 5))
|
||||
model = SpectralCoclustering(**params)
|
||||
with pytest.raises(type_err, match=err_msg):
|
||||
model.fit(data)
|
||||
|
||||
|
||||
@pytest.mark.parametrize(
|
||||
"params, type_err, err_msg",
|
||||
[
|
||||
({"n_init": 0}, ValueError, "n_init == 0, must be >= 1."),
|
||||
({"n_init": 1.5}, TypeError, "n_init must be an instance of"),
|
||||
(
|
||||
{"n_clusters": (3, 3, 3)},
|
||||
ValueError,
|
||||
r"Incorrect parameter n_clusters has value: \(3, 3, 3\)",
|
||||
),
|
||||
(
|
||||
{"n_clusters": "abc"},
|
||||
ValueError,
|
||||
"Incorrect parameter n_clusters has value: abc",
|
||||
),
|
||||
(
|
||||
{"n_clusters": (3, "abc")},
|
||||
ValueError,
|
||||
r"Incorrect parameter n_clusters has value: \(3, 'abc'\)",
|
||||
),
|
||||
(
|
||||
{"n_clusters": ("abc", 3)},
|
||||
ValueError,
|
||||
r"Incorrect parameter n_clusters has value: \('abc', 3\)",
|
||||
),
|
||||
({"method": "unknown"}, ValueError, "Unknown method: 'unknown'"),
|
||||
({"n_components": 0}, ValueError, "n_components == 0, must be >= 1."),
|
||||
({"n_components": 1.5}, TypeError, "n_components must be an instance of"),
|
||||
({"n_components": 3, "n_best": 4}, ValueError, "n_best == 4, must be <= 3."),
|
||||
({"n_best": 0}, ValueError, "n_best == 0, must be >= 1."),
|
||||
({"n_best": 1.5}, TypeError, "n_best must be an instance of"),
|
||||
({"svd_method": "unknown"}, ValueError, "Unknown SVD method: 'unknown'"),
|
||||
],
|
||||
)
|
||||
def test_spectralbiclustering_parameter_validation(params, type_err, err_msg):
|
||||
"""Check parameters validation in `SpectralBiClustering`"""
|
||||
data = np.arange(25).reshape((5, 5))
|
||||
model = SpectralBiclustering(**params)
|
||||
with pytest.raises(type_err, match=err_msg):
|
||||
model.fit(data)
|
||||
|
||||
|
||||
@pytest.mark.parametrize("est", (SpectralBiclustering(), SpectralCoclustering()))
|
||||
def test_n_features_in_(est):
|
||||
|
||||
X, _, _ = make_biclusters((3, 3), 3, random_state=0)
|
||||
|
||||
assert not hasattr(est, "n_features_in_")
|
||||
est.fit(X)
|
||||
assert est.n_features_in_ == 3
|
||||
@@ -0,0 +1,230 @@
|
||||
"""
|
||||
Tests for the birch clustering algorithm.
|
||||
"""
|
||||
|
||||
from scipy import sparse
|
||||
import numpy as np
|
||||
import pytest
|
||||
|
||||
from sklearn.cluster.tests.common import generate_clustered_data
|
||||
from sklearn.cluster import Birch
|
||||
from sklearn.cluster import AgglomerativeClustering
|
||||
from sklearn.datasets import make_blobs
|
||||
from sklearn.exceptions import ConvergenceWarning
|
||||
from sklearn.linear_model import ElasticNet
|
||||
from sklearn.metrics import pairwise_distances_argmin, v_measure_score
|
||||
|
||||
from sklearn.utils._testing import assert_almost_equal
|
||||
from sklearn.utils._testing import assert_array_equal
|
||||
from sklearn.utils._testing import assert_array_almost_equal
|
||||
|
||||
|
||||
def test_n_samples_leaves_roots():
|
||||
# Sanity check for the number of samples in leaves and roots
|
||||
X, y = make_blobs(n_samples=10)
|
||||
brc = Birch()
|
||||
brc.fit(X)
|
||||
n_samples_root = sum([sc.n_samples_ for sc in brc.root_.subclusters_])
|
||||
n_samples_leaves = sum(
|
||||
[sc.n_samples_ for leaf in brc._get_leaves() for sc in leaf.subclusters_]
|
||||
)
|
||||
assert n_samples_leaves == X.shape[0]
|
||||
assert n_samples_root == X.shape[0]
|
||||
|
||||
|
||||
def test_partial_fit():
|
||||
# Test that fit is equivalent to calling partial_fit multiple times
|
||||
X, y = make_blobs(n_samples=100)
|
||||
brc = Birch(n_clusters=3)
|
||||
brc.fit(X)
|
||||
brc_partial = Birch(n_clusters=None)
|
||||
brc_partial.partial_fit(X[:50])
|
||||
brc_partial.partial_fit(X[50:])
|
||||
assert_array_almost_equal(brc_partial.subcluster_centers_, brc.subcluster_centers_)
|
||||
|
||||
# Test that same global labels are obtained after calling partial_fit
|
||||
# with None
|
||||
brc_partial.set_params(n_clusters=3)
|
||||
brc_partial.partial_fit(None)
|
||||
assert_array_equal(brc_partial.subcluster_labels_, brc.subcluster_labels_)
|
||||
|
||||
|
||||
def test_birch_predict():
|
||||
# Test the predict method predicts the nearest centroid.
|
||||
rng = np.random.RandomState(0)
|
||||
X = generate_clustered_data(n_clusters=3, n_features=3, n_samples_per_cluster=10)
|
||||
|
||||
# n_samples * n_samples_per_cluster
|
||||
shuffle_indices = np.arange(30)
|
||||
rng.shuffle(shuffle_indices)
|
||||
X_shuffle = X[shuffle_indices, :]
|
||||
brc = Birch(n_clusters=4, threshold=1.0)
|
||||
brc.fit(X_shuffle)
|
||||
centroids = brc.subcluster_centers_
|
||||
assert_array_equal(brc.labels_, brc.predict(X_shuffle))
|
||||
nearest_centroid = pairwise_distances_argmin(X_shuffle, centroids)
|
||||
assert_almost_equal(v_measure_score(nearest_centroid, brc.labels_), 1.0)
|
||||
|
||||
|
||||
def test_n_clusters():
|
||||
# Test that n_clusters param works properly
|
||||
X, y = make_blobs(n_samples=100, centers=10)
|
||||
brc1 = Birch(n_clusters=10)
|
||||
brc1.fit(X)
|
||||
assert len(brc1.subcluster_centers_) > 10
|
||||
assert len(np.unique(brc1.labels_)) == 10
|
||||
|
||||
# Test that n_clusters = Agglomerative Clustering gives
|
||||
# the same results.
|
||||
gc = AgglomerativeClustering(n_clusters=10)
|
||||
brc2 = Birch(n_clusters=gc)
|
||||
brc2.fit(X)
|
||||
assert_array_equal(brc1.subcluster_labels_, brc2.subcluster_labels_)
|
||||
assert_array_equal(brc1.labels_, brc2.labels_)
|
||||
|
||||
# Test that the wrong global clustering step raises an Error.
|
||||
clf = ElasticNet()
|
||||
brc3 = Birch(n_clusters=clf)
|
||||
err_msg = "n_clusters should be an instance of ClusterMixin or an int"
|
||||
with pytest.raises(TypeError, match=err_msg):
|
||||
brc3.fit(X)
|
||||
|
||||
# Test that a small number of clusters raises a warning.
|
||||
brc4 = Birch(threshold=10000.0)
|
||||
with pytest.warns(ConvergenceWarning):
|
||||
brc4.fit(X)
|
||||
|
||||
|
||||
def test_sparse_X():
|
||||
# Test that sparse and dense data give same results
|
||||
X, y = make_blobs(n_samples=100, centers=10)
|
||||
brc = Birch(n_clusters=10)
|
||||
brc.fit(X)
|
||||
|
||||
csr = sparse.csr_matrix(X)
|
||||
brc_sparse = Birch(n_clusters=10)
|
||||
brc_sparse.fit(csr)
|
||||
|
||||
assert_array_equal(brc.labels_, brc_sparse.labels_)
|
||||
assert_array_almost_equal(brc.subcluster_centers_, brc_sparse.subcluster_centers_)
|
||||
|
||||
|
||||
def test_partial_fit_second_call_error_checks():
|
||||
# second partial fit calls will error when n_features is not consistent
|
||||
# with the first call
|
||||
X, y = make_blobs(n_samples=100)
|
||||
brc = Birch(n_clusters=3)
|
||||
brc.partial_fit(X, y)
|
||||
|
||||
msg = "X has 1 features, but Birch is expecting 2 features"
|
||||
with pytest.raises(ValueError, match=msg):
|
||||
brc.partial_fit(X[:, [0]], y)
|
||||
|
||||
|
||||
def check_branching_factor(node, branching_factor):
|
||||
subclusters = node.subclusters_
|
||||
assert branching_factor >= len(subclusters)
|
||||
for cluster in subclusters:
|
||||
if cluster.child_:
|
||||
check_branching_factor(cluster.child_, branching_factor)
|
||||
|
||||
|
||||
def test_branching_factor():
|
||||
# Test that nodes have at max branching_factor number of subclusters
|
||||
X, y = make_blobs()
|
||||
branching_factor = 9
|
||||
|
||||
# Purposefully set a low threshold to maximize the subclusters.
|
||||
brc = Birch(n_clusters=None, branching_factor=branching_factor, threshold=0.01)
|
||||
brc.fit(X)
|
||||
check_branching_factor(brc.root_, branching_factor)
|
||||
brc = Birch(n_clusters=3, branching_factor=branching_factor, threshold=0.01)
|
||||
brc.fit(X)
|
||||
check_branching_factor(brc.root_, branching_factor)
|
||||
|
||||
|
||||
def check_threshold(birch_instance, threshold):
|
||||
"""Use the leaf linked list for traversal"""
|
||||
current_leaf = birch_instance.dummy_leaf_.next_leaf_
|
||||
while current_leaf:
|
||||
subclusters = current_leaf.subclusters_
|
||||
for sc in subclusters:
|
||||
assert threshold >= sc.radius
|
||||
current_leaf = current_leaf.next_leaf_
|
||||
|
||||
|
||||
def test_threshold():
|
||||
# Test that the leaf subclusters have a threshold lesser than radius
|
||||
X, y = make_blobs(n_samples=80, centers=4)
|
||||
brc = Birch(threshold=0.5, n_clusters=None)
|
||||
brc.fit(X)
|
||||
check_threshold(brc, 0.5)
|
||||
|
||||
brc = Birch(threshold=5.0, n_clusters=None)
|
||||
brc.fit(X)
|
||||
check_threshold(brc, 5.0)
|
||||
|
||||
|
||||
def test_birch_n_clusters_long_int():
|
||||
# Check that birch supports n_clusters with np.int64 dtype, for instance
|
||||
# coming from np.arange. #16484
|
||||
X, _ = make_blobs(random_state=0)
|
||||
n_clusters = np.int64(5)
|
||||
Birch(n_clusters=n_clusters).fit(X)
|
||||
|
||||
|
||||
# TODO: Remove in 1.2
|
||||
@pytest.mark.parametrize("attribute", ["fit_", "partial_fit_"])
|
||||
def test_birch_fit_attributes_deprecated(attribute):
|
||||
"""Test that fit_ and partial_fit_ attributes are deprecated."""
|
||||
msg = f"`{attribute}` is deprecated in 1.0 and will be removed in 1.2"
|
||||
X, y = make_blobs(n_samples=10)
|
||||
brc = Birch().fit(X, y)
|
||||
|
||||
with pytest.warns(FutureWarning, match=msg):
|
||||
getattr(brc, attribute)
|
||||
|
||||
|
||||
@pytest.mark.parametrize(
|
||||
"params, err_type, err_msg",
|
||||
[
|
||||
({"threshold": -1.0}, ValueError, "threshold == -1.0, must be > 0.0."),
|
||||
({"threshold": 0.0}, ValueError, "threshold == 0.0, must be > 0.0."),
|
||||
({"branching_factor": 0}, ValueError, "branching_factor == 0, must be > 1."),
|
||||
({"branching_factor": 1}, ValueError, "branching_factor == 1, must be > 1."),
|
||||
(
|
||||
{"branching_factor": 1.5},
|
||||
TypeError,
|
||||
"branching_factor must be an instance of int, not float.",
|
||||
),
|
||||
({"branching_factor": -2}, ValueError, "branching_factor == -2, must be > 1."),
|
||||
({"n_clusters": 0}, ValueError, "n_clusters == 0, must be >= 1."),
|
||||
(
|
||||
{"n_clusters": 2.5},
|
||||
TypeError,
|
||||
"n_clusters must be an instance of int, not float.",
|
||||
),
|
||||
(
|
||||
{"n_clusters": "whatever"},
|
||||
TypeError,
|
||||
"n_clusters should be an instance of ClusterMixin or an int",
|
||||
),
|
||||
({"n_clusters": -3}, ValueError, "n_clusters == -3, must be >= 1."),
|
||||
],
|
||||
)
|
||||
def test_birch_params_validation(params, err_type, err_msg):
|
||||
"""Check the parameters validation in `Birch`."""
|
||||
X, _ = make_blobs(n_samples=80, centers=4)
|
||||
with pytest.raises(err_type, match=err_msg):
|
||||
Birch(**params).fit(X)
|
||||
|
||||
|
||||
def test_feature_names_out():
|
||||
"""Check `get_feature_names_out` for `Birch`."""
|
||||
X, _ = make_blobs(n_samples=80, n_features=4, random_state=0)
|
||||
brc = Birch(n_clusters=4)
|
||||
brc.fit(X)
|
||||
n_clusters = brc.subcluster_centers_.shape[0]
|
||||
|
||||
names_out = brc.get_feature_names_out()
|
||||
assert_array_equal([f"birch{i}" for i in range(n_clusters)], names_out)
|
||||
@@ -0,0 +1,160 @@
|
||||
import numpy as np
|
||||
import pytest
|
||||
import scipy.sparse as sp
|
||||
|
||||
from sklearn.utils._testing import assert_array_equal, assert_allclose
|
||||
from sklearn.cluster import BisectingKMeans
|
||||
|
||||
|
||||
@pytest.mark.parametrize("bisecting_strategy", ["biggest_inertia", "largest_cluster"])
|
||||
def test_three_clusters(bisecting_strategy):
|
||||
"""Tries to perform bisect k-means for three clusters to check
|
||||
if splitting data is performed correctly.
|
||||
"""
|
||||
|
||||
# X = np.array([[1, 2], [1, 4], [1, 0],
|
||||
# [10, 2], [10, 4], [10, 0],
|
||||
# [10, 6], [10, 8], [10, 10]])
|
||||
|
||||
# X[0][1] swapped with X[1][1] intentionally for checking labeling
|
||||
X = np.array(
|
||||
[[1, 2], [10, 4], [1, 0], [10, 2], [1, 4], [10, 0], [10, 6], [10, 8], [10, 10]]
|
||||
)
|
||||
bisect_means = BisectingKMeans(
|
||||
n_clusters=3, random_state=0, bisecting_strategy=bisecting_strategy
|
||||
)
|
||||
bisect_means.fit(X)
|
||||
|
||||
expected_centers = [[10, 2], [10, 8], [1, 2]]
|
||||
expected_predict = [2, 0]
|
||||
expected_labels = [2, 0, 2, 0, 2, 0, 1, 1, 1]
|
||||
|
||||
assert_allclose(expected_centers, bisect_means.cluster_centers_)
|
||||
assert_array_equal(expected_predict, bisect_means.predict([[0, 0], [12, 3]]))
|
||||
assert_array_equal(expected_labels, bisect_means.labels_)
|
||||
|
||||
|
||||
def test_sparse():
|
||||
"""Test Bisecting K-Means with sparse data.
|
||||
|
||||
Checks if labels and centers are the same between dense and sparse.
|
||||
"""
|
||||
|
||||
rng = np.random.RandomState(0)
|
||||
|
||||
X = rng.rand(20, 2)
|
||||
X[X < 0.8] = 0
|
||||
X_csr = sp.csr_matrix(X)
|
||||
|
||||
bisect_means = BisectingKMeans(n_clusters=3, random_state=0)
|
||||
|
||||
bisect_means.fit(X_csr)
|
||||
sparse_centers = bisect_means.cluster_centers_
|
||||
|
||||
bisect_means.fit(X)
|
||||
normal_centers = bisect_means.cluster_centers_
|
||||
|
||||
# Check if results is the same for dense and sparse data
|
||||
assert_allclose(normal_centers, sparse_centers, atol=1e-8)
|
||||
|
||||
|
||||
@pytest.mark.parametrize("n_clusters", [4, 5])
|
||||
def test_n_clusters(n_clusters):
|
||||
"""Test if resulting labels are in range [0, n_clusters - 1]."""
|
||||
|
||||
rng = np.random.RandomState(0)
|
||||
X = rng.rand(10, 2)
|
||||
|
||||
bisect_means = BisectingKMeans(n_clusters=n_clusters, random_state=0)
|
||||
bisect_means.fit(X)
|
||||
|
||||
assert_array_equal(np.unique(bisect_means.labels_), np.arange(n_clusters))
|
||||
|
||||
|
||||
def test_one_cluster():
|
||||
"""Test single cluster."""
|
||||
|
||||
X = np.array([[1, 2], [10, 2], [10, 8]])
|
||||
|
||||
bisect_means = BisectingKMeans(n_clusters=1, random_state=0).fit(X)
|
||||
|
||||
# All labels from fit or predict should be equal 0
|
||||
assert all(bisect_means.labels_ == 0)
|
||||
assert all(bisect_means.predict(X) == 0)
|
||||
|
||||
assert_allclose(bisect_means.cluster_centers_, X.mean(axis=0).reshape(1, -1))
|
||||
|
||||
|
||||
@pytest.mark.parametrize(
|
||||
"param, match",
|
||||
[
|
||||
# Test bisecting_strategy param
|
||||
(
|
||||
{"bisecting_strategy": "None"},
|
||||
"Bisect Strategy must be 'biggest_inertia' or 'largest_cluster'",
|
||||
),
|
||||
# Test init array
|
||||
(
|
||||
{"init": np.ones((5, 2))},
|
||||
"BisectingKMeans does not support init as array.",
|
||||
),
|
||||
],
|
||||
)
|
||||
def test_wrong_params(param, match):
|
||||
"""Test Exceptions at check_params function."""
|
||||
rng = np.random.RandomState(0)
|
||||
X = rng.rand(5, 2)
|
||||
|
||||
with pytest.raises(ValueError, match=match):
|
||||
bisect_means = BisectingKMeans(n_clusters=3, **param)
|
||||
bisect_means.fit(X)
|
||||
|
||||
|
||||
@pytest.mark.parametrize("is_sparse", [True, False])
|
||||
def test_fit_predict(is_sparse):
|
||||
"""Check if labels from fit(X) method are same as from fit(X).predict(X)."""
|
||||
rng = np.random.RandomState(0)
|
||||
|
||||
X = rng.rand(10, 2)
|
||||
|
||||
if is_sparse:
|
||||
X[X < 0.8] = 0
|
||||
X = sp.csr_matrix(X)
|
||||
|
||||
bisect_means = BisectingKMeans(n_clusters=3, random_state=0)
|
||||
bisect_means.fit(X)
|
||||
|
||||
assert_array_equal(bisect_means.labels_, bisect_means.predict(X))
|
||||
|
||||
|
||||
@pytest.mark.parametrize("is_sparse", [True, False])
|
||||
def test_dtype_preserved(is_sparse, global_dtype):
|
||||
"""Check that centers dtype is the same as input data dtype."""
|
||||
rng = np.random.RandomState(0)
|
||||
X = rng.rand(10, 2).astype(global_dtype, copy=False)
|
||||
|
||||
if is_sparse:
|
||||
X[X < 0.8] = 0
|
||||
X = sp.csr_matrix(X)
|
||||
|
||||
km = BisectingKMeans(n_clusters=3, random_state=0)
|
||||
km.fit(X)
|
||||
|
||||
assert km.cluster_centers_.dtype == global_dtype
|
||||
|
||||
|
||||
@pytest.mark.parametrize("is_sparse", [True, False])
|
||||
def test_float32_float64_equivalence(is_sparse):
|
||||
"""Check that the results are the same between float32 and float64."""
|
||||
rng = np.random.RandomState(0)
|
||||
X = rng.rand(10, 2)
|
||||
|
||||
if is_sparse:
|
||||
X[X < 0.8] = 0
|
||||
X = sp.csr_matrix(X)
|
||||
|
||||
km64 = BisectingKMeans(n_clusters=3, random_state=0).fit(X)
|
||||
km32 = BisectingKMeans(n_clusters=3, random_state=0).fit(X.astype(np.float32))
|
||||
|
||||
assert_allclose(km32.cluster_centers_, km64.cluster_centers_)
|
||||
assert_array_equal(km32.labels_, km64.labels_)
|
||||
@@ -0,0 +1,460 @@
|
||||
"""
|
||||
Tests for DBSCAN clustering algorithm
|
||||
"""
|
||||
|
||||
import pickle
|
||||
|
||||
import numpy as np
|
||||
|
||||
import warnings
|
||||
|
||||
from scipy.spatial import distance
|
||||
from scipy import sparse
|
||||
|
||||
import pytest
|
||||
|
||||
from sklearn.utils._testing import assert_array_equal
|
||||
from sklearn.neighbors import NearestNeighbors
|
||||
from sklearn.cluster import DBSCAN
|
||||
from sklearn.cluster import dbscan
|
||||
from sklearn.cluster.tests.common import generate_clustered_data
|
||||
from sklearn.metrics.pairwise import pairwise_distances
|
||||
|
||||
|
||||
n_clusters = 3
|
||||
X = generate_clustered_data(n_clusters=n_clusters)
|
||||
|
||||
|
||||
def test_dbscan_similarity():
|
||||
# Tests the DBSCAN algorithm with a similarity array.
|
||||
# Parameters chosen specifically for this task.
|
||||
eps = 0.15
|
||||
min_samples = 10
|
||||
# Compute similarities
|
||||
D = distance.squareform(distance.pdist(X))
|
||||
D /= np.max(D)
|
||||
# Compute DBSCAN
|
||||
core_samples, labels = dbscan(
|
||||
D, metric="precomputed", eps=eps, min_samples=min_samples
|
||||
)
|
||||
# number of clusters, ignoring noise if present
|
||||
n_clusters_1 = len(set(labels)) - (1 if -1 in labels else 0)
|
||||
|
||||
assert n_clusters_1 == n_clusters
|
||||
|
||||
db = DBSCAN(metric="precomputed", eps=eps, min_samples=min_samples)
|
||||
labels = db.fit(D).labels_
|
||||
|
||||
n_clusters_2 = len(set(labels)) - int(-1 in labels)
|
||||
assert n_clusters_2 == n_clusters
|
||||
|
||||
|
||||
def test_dbscan_feature():
|
||||
# Tests the DBSCAN algorithm with a feature vector array.
|
||||
# Parameters chosen specifically for this task.
|
||||
# Different eps to other test, because distance is not normalised.
|
||||
eps = 0.8
|
||||
min_samples = 10
|
||||
metric = "euclidean"
|
||||
# Compute DBSCAN
|
||||
# parameters chosen for task
|
||||
core_samples, labels = dbscan(X, metric=metric, eps=eps, min_samples=min_samples)
|
||||
|
||||
# number of clusters, ignoring noise if present
|
||||
n_clusters_1 = len(set(labels)) - int(-1 in labels)
|
||||
assert n_clusters_1 == n_clusters
|
||||
|
||||
db = DBSCAN(metric=metric, eps=eps, min_samples=min_samples)
|
||||
labels = db.fit(X).labels_
|
||||
|
||||
n_clusters_2 = len(set(labels)) - int(-1 in labels)
|
||||
assert n_clusters_2 == n_clusters
|
||||
|
||||
|
||||
def test_dbscan_sparse():
|
||||
core_sparse, labels_sparse = dbscan(sparse.lil_matrix(X), eps=0.8, min_samples=10)
|
||||
core_dense, labels_dense = dbscan(X, eps=0.8, min_samples=10)
|
||||
assert_array_equal(core_dense, core_sparse)
|
||||
assert_array_equal(labels_dense, labels_sparse)
|
||||
|
||||
|
||||
@pytest.mark.parametrize("include_self", [False, True])
|
||||
def test_dbscan_sparse_precomputed(include_self):
|
||||
D = pairwise_distances(X)
|
||||
nn = NearestNeighbors(radius=0.9).fit(X)
|
||||
X_ = X if include_self else None
|
||||
D_sparse = nn.radius_neighbors_graph(X=X_, mode="distance")
|
||||
# Ensure it is sparse not merely on diagonals:
|
||||
assert D_sparse.nnz < D.shape[0] * (D.shape[0] - 1)
|
||||
core_sparse, labels_sparse = dbscan(
|
||||
D_sparse, eps=0.8, min_samples=10, metric="precomputed"
|
||||
)
|
||||
core_dense, labels_dense = dbscan(D, eps=0.8, min_samples=10, metric="precomputed")
|
||||
assert_array_equal(core_dense, core_sparse)
|
||||
assert_array_equal(labels_dense, labels_sparse)
|
||||
|
||||
|
||||
def test_dbscan_sparse_precomputed_different_eps():
|
||||
# test that precomputed neighbors graph is filtered if computed with
|
||||
# a radius larger than DBSCAN's eps.
|
||||
lower_eps = 0.2
|
||||
nn = NearestNeighbors(radius=lower_eps).fit(X)
|
||||
D_sparse = nn.radius_neighbors_graph(X, mode="distance")
|
||||
dbscan_lower = dbscan(D_sparse, eps=lower_eps, metric="precomputed")
|
||||
|
||||
higher_eps = lower_eps + 0.7
|
||||
nn = NearestNeighbors(radius=higher_eps).fit(X)
|
||||
D_sparse = nn.radius_neighbors_graph(X, mode="distance")
|
||||
dbscan_higher = dbscan(D_sparse, eps=lower_eps, metric="precomputed")
|
||||
|
||||
assert_array_equal(dbscan_lower[0], dbscan_higher[0])
|
||||
assert_array_equal(dbscan_lower[1], dbscan_higher[1])
|
||||
|
||||
|
||||
@pytest.mark.parametrize("use_sparse", [True, False])
|
||||
@pytest.mark.parametrize("metric", ["precomputed", "minkowski"])
|
||||
def test_dbscan_input_not_modified(use_sparse, metric):
|
||||
# test that the input is not modified by dbscan
|
||||
X = np.random.RandomState(0).rand(10, 10)
|
||||
X = sparse.csr_matrix(X) if use_sparse else X
|
||||
X_copy = X.copy()
|
||||
dbscan(X, metric=metric)
|
||||
|
||||
if use_sparse:
|
||||
assert_array_equal(X.toarray(), X_copy.toarray())
|
||||
else:
|
||||
assert_array_equal(X, X_copy)
|
||||
|
||||
|
||||
def test_dbscan_no_core_samples():
|
||||
rng = np.random.RandomState(0)
|
||||
X = rng.rand(40, 10)
|
||||
X[X < 0.8] = 0
|
||||
|
||||
for X_ in [X, sparse.csr_matrix(X)]:
|
||||
db = DBSCAN(min_samples=6).fit(X_)
|
||||
assert_array_equal(db.components_, np.empty((0, X_.shape[1])))
|
||||
assert_array_equal(db.labels_, -1)
|
||||
assert db.core_sample_indices_.shape == (0,)
|
||||
|
||||
|
||||
def test_dbscan_callable():
|
||||
# Tests the DBSCAN algorithm with a callable metric.
|
||||
# Parameters chosen specifically for this task.
|
||||
# Different eps to other test, because distance is not normalised.
|
||||
eps = 0.8
|
||||
min_samples = 10
|
||||
# metric is the function reference, not the string key.
|
||||
metric = distance.euclidean
|
||||
# Compute DBSCAN
|
||||
# parameters chosen for task
|
||||
core_samples, labels = dbscan(
|
||||
X, metric=metric, eps=eps, min_samples=min_samples, algorithm="ball_tree"
|
||||
)
|
||||
|
||||
# number of clusters, ignoring noise if present
|
||||
n_clusters_1 = len(set(labels)) - int(-1 in labels)
|
||||
assert n_clusters_1 == n_clusters
|
||||
|
||||
db = DBSCAN(metric=metric, eps=eps, min_samples=min_samples, algorithm="ball_tree")
|
||||
labels = db.fit(X).labels_
|
||||
|
||||
n_clusters_2 = len(set(labels)) - int(-1 in labels)
|
||||
assert n_clusters_2 == n_clusters
|
||||
|
||||
|
||||
def test_dbscan_metric_params():
|
||||
# Tests that DBSCAN works with the metrics_params argument.
|
||||
eps = 0.8
|
||||
min_samples = 10
|
||||
p = 1
|
||||
|
||||
# Compute DBSCAN with metric_params arg
|
||||
|
||||
with warnings.catch_warnings(record=True) as warns:
|
||||
db = DBSCAN(
|
||||
metric="minkowski",
|
||||
metric_params={"p": p},
|
||||
eps=eps,
|
||||
p=None,
|
||||
min_samples=min_samples,
|
||||
algorithm="ball_tree",
|
||||
).fit(X)
|
||||
assert not warns, warns[0].message
|
||||
core_sample_1, labels_1 = db.core_sample_indices_, db.labels_
|
||||
|
||||
# Test that sample labels are the same as passing Minkowski 'p' directly
|
||||
db = DBSCAN(
|
||||
metric="minkowski", eps=eps, min_samples=min_samples, algorithm="ball_tree", p=p
|
||||
).fit(X)
|
||||
core_sample_2, labels_2 = db.core_sample_indices_, db.labels_
|
||||
|
||||
assert_array_equal(core_sample_1, core_sample_2)
|
||||
assert_array_equal(labels_1, labels_2)
|
||||
|
||||
# Minkowski with p=1 should be equivalent to Manhattan distance
|
||||
db = DBSCAN(
|
||||
metric="manhattan", eps=eps, min_samples=min_samples, algorithm="ball_tree"
|
||||
).fit(X)
|
||||
core_sample_3, labels_3 = db.core_sample_indices_, db.labels_
|
||||
|
||||
assert_array_equal(core_sample_1, core_sample_3)
|
||||
assert_array_equal(labels_1, labels_3)
|
||||
|
||||
with pytest.warns(
|
||||
SyntaxWarning,
|
||||
match=(
|
||||
"Parameter p is found in metric_params. "
|
||||
"The corresponding parameter from __init__ "
|
||||
"is ignored."
|
||||
),
|
||||
):
|
||||
# Test that checks p is ignored in favor of metric_params={'p': <val>}
|
||||
db = DBSCAN(
|
||||
metric="minkowski",
|
||||
metric_params={"p": p},
|
||||
eps=eps,
|
||||
p=p + 1,
|
||||
min_samples=min_samples,
|
||||
algorithm="ball_tree",
|
||||
).fit(X)
|
||||
core_sample_4, labels_4 = db.core_sample_indices_, db.labels_
|
||||
|
||||
assert_array_equal(core_sample_1, core_sample_4)
|
||||
assert_array_equal(labels_1, labels_4)
|
||||
|
||||
|
||||
def test_dbscan_balltree():
|
||||
# Tests the DBSCAN algorithm with balltree for neighbor calculation.
|
||||
eps = 0.8
|
||||
min_samples = 10
|
||||
|
||||
D = pairwise_distances(X)
|
||||
core_samples, labels = dbscan(
|
||||
D, metric="precomputed", eps=eps, min_samples=min_samples
|
||||
)
|
||||
|
||||
# number of clusters, ignoring noise if present
|
||||
n_clusters_1 = len(set(labels)) - int(-1 in labels)
|
||||
assert n_clusters_1 == n_clusters
|
||||
|
||||
db = DBSCAN(p=2.0, eps=eps, min_samples=min_samples, algorithm="ball_tree")
|
||||
labels = db.fit(X).labels_
|
||||
|
||||
n_clusters_2 = len(set(labels)) - int(-1 in labels)
|
||||
assert n_clusters_2 == n_clusters
|
||||
|
||||
db = DBSCAN(p=2.0, eps=eps, min_samples=min_samples, algorithm="kd_tree")
|
||||
labels = db.fit(X).labels_
|
||||
|
||||
n_clusters_3 = len(set(labels)) - int(-1 in labels)
|
||||
assert n_clusters_3 == n_clusters
|
||||
|
||||
db = DBSCAN(p=1.0, eps=eps, min_samples=min_samples, algorithm="ball_tree")
|
||||
labels = db.fit(X).labels_
|
||||
|
||||
n_clusters_4 = len(set(labels)) - int(-1 in labels)
|
||||
assert n_clusters_4 == n_clusters
|
||||
|
||||
db = DBSCAN(leaf_size=20, eps=eps, min_samples=min_samples, algorithm="ball_tree")
|
||||
labels = db.fit(X).labels_
|
||||
|
||||
n_clusters_5 = len(set(labels)) - int(-1 in labels)
|
||||
assert n_clusters_5 == n_clusters
|
||||
|
||||
|
||||
def test_input_validation():
|
||||
# DBSCAN.fit should accept a list of lists.
|
||||
X = [[1.0, 2.0], [3.0, 4.0]]
|
||||
DBSCAN().fit(X) # must not raise exception
|
||||
|
||||
|
||||
@pytest.mark.parametrize(
|
||||
"args",
|
||||
[
|
||||
{"algorithm": "blah"},
|
||||
{"metric": "blah"},
|
||||
],
|
||||
)
|
||||
def test_dbscan_badargs(args):
|
||||
# Test bad argument values: these should all raise ValueErrors
|
||||
with pytest.raises(ValueError):
|
||||
dbscan(X, **args)
|
||||
|
||||
|
||||
def test_pickle():
|
||||
obj = DBSCAN()
|
||||
s = pickle.dumps(obj)
|
||||
assert type(pickle.loads(s)) == obj.__class__
|
||||
|
||||
|
||||
def test_boundaries():
|
||||
# ensure min_samples is inclusive of core point
|
||||
core, _ = dbscan([[0], [1]], eps=2, min_samples=2)
|
||||
assert 0 in core
|
||||
# ensure eps is inclusive of circumference
|
||||
core, _ = dbscan([[0], [1], [1]], eps=1, min_samples=2)
|
||||
assert 0 in core
|
||||
core, _ = dbscan([[0], [1], [1]], eps=0.99, min_samples=2)
|
||||
assert 0 not in core
|
||||
|
||||
|
||||
def test_weighted_dbscan():
|
||||
# ensure sample_weight is validated
|
||||
with pytest.raises(ValueError):
|
||||
dbscan([[0], [1]], sample_weight=[2])
|
||||
with pytest.raises(ValueError):
|
||||
dbscan([[0], [1]], sample_weight=[2, 3, 4])
|
||||
|
||||
# ensure sample_weight has an effect
|
||||
assert_array_equal([], dbscan([[0], [1]], sample_weight=None, min_samples=6)[0])
|
||||
assert_array_equal([], dbscan([[0], [1]], sample_weight=[5, 5], min_samples=6)[0])
|
||||
assert_array_equal([0], dbscan([[0], [1]], sample_weight=[6, 5], min_samples=6)[0])
|
||||
assert_array_equal(
|
||||
[0, 1], dbscan([[0], [1]], sample_weight=[6, 6], min_samples=6)[0]
|
||||
)
|
||||
|
||||
# points within eps of each other:
|
||||
assert_array_equal(
|
||||
[0, 1], dbscan([[0], [1]], eps=1.5, sample_weight=[5, 1], min_samples=6)[0]
|
||||
)
|
||||
# and effect of non-positive and non-integer sample_weight:
|
||||
assert_array_equal(
|
||||
[], dbscan([[0], [1]], sample_weight=[5, 0], eps=1.5, min_samples=6)[0]
|
||||
)
|
||||
assert_array_equal(
|
||||
[0, 1], dbscan([[0], [1]], sample_weight=[5.9, 0.1], eps=1.5, min_samples=6)[0]
|
||||
)
|
||||
assert_array_equal(
|
||||
[0, 1], dbscan([[0], [1]], sample_weight=[6, 0], eps=1.5, min_samples=6)[0]
|
||||
)
|
||||
assert_array_equal(
|
||||
[], dbscan([[0], [1]], sample_weight=[6, -1], eps=1.5, min_samples=6)[0]
|
||||
)
|
||||
|
||||
# for non-negative sample_weight, cores should be identical to repetition
|
||||
rng = np.random.RandomState(42)
|
||||
sample_weight = rng.randint(0, 5, X.shape[0])
|
||||
core1, label1 = dbscan(X, sample_weight=sample_weight)
|
||||
assert len(label1) == len(X)
|
||||
|
||||
X_repeated = np.repeat(X, sample_weight, axis=0)
|
||||
core_repeated, label_repeated = dbscan(X_repeated)
|
||||
core_repeated_mask = np.zeros(X_repeated.shape[0], dtype=bool)
|
||||
core_repeated_mask[core_repeated] = True
|
||||
core_mask = np.zeros(X.shape[0], dtype=bool)
|
||||
core_mask[core1] = True
|
||||
assert_array_equal(np.repeat(core_mask, sample_weight), core_repeated_mask)
|
||||
|
||||
# sample_weight should work with precomputed distance matrix
|
||||
D = pairwise_distances(X)
|
||||
core3, label3 = dbscan(D, sample_weight=sample_weight, metric="precomputed")
|
||||
assert_array_equal(core1, core3)
|
||||
assert_array_equal(label1, label3)
|
||||
|
||||
# sample_weight should work with estimator
|
||||
est = DBSCAN().fit(X, sample_weight=sample_weight)
|
||||
core4 = est.core_sample_indices_
|
||||
label4 = est.labels_
|
||||
assert_array_equal(core1, core4)
|
||||
assert_array_equal(label1, label4)
|
||||
|
||||
est = DBSCAN()
|
||||
label5 = est.fit_predict(X, sample_weight=sample_weight)
|
||||
core5 = est.core_sample_indices_
|
||||
assert_array_equal(core1, core5)
|
||||
assert_array_equal(label1, label5)
|
||||
assert_array_equal(label1, est.labels_)
|
||||
|
||||
|
||||
@pytest.mark.parametrize("algorithm", ["brute", "kd_tree", "ball_tree"])
|
||||
def test_dbscan_core_samples_toy(algorithm):
|
||||
X = [[0], [2], [3], [4], [6], [8], [10]]
|
||||
n_samples = len(X)
|
||||
|
||||
# Degenerate case: every sample is a core sample, either with its own
|
||||
# cluster or including other close core samples.
|
||||
core_samples, labels = dbscan(X, algorithm=algorithm, eps=1, min_samples=1)
|
||||
assert_array_equal(core_samples, np.arange(n_samples))
|
||||
assert_array_equal(labels, [0, 1, 1, 1, 2, 3, 4])
|
||||
|
||||
# With eps=1 and min_samples=2 only the 3 samples from the denser area
|
||||
# are core samples. All other points are isolated and considered noise.
|
||||
core_samples, labels = dbscan(X, algorithm=algorithm, eps=1, min_samples=2)
|
||||
assert_array_equal(core_samples, [1, 2, 3])
|
||||
assert_array_equal(labels, [-1, 0, 0, 0, -1, -1, -1])
|
||||
|
||||
# Only the sample in the middle of the dense area is core. Its two
|
||||
# neighbors are edge samples. Remaining samples are noise.
|
||||
core_samples, labels = dbscan(X, algorithm=algorithm, eps=1, min_samples=3)
|
||||
assert_array_equal(core_samples, [2])
|
||||
assert_array_equal(labels, [-1, 0, 0, 0, -1, -1, -1])
|
||||
|
||||
# It's no longer possible to extract core samples with eps=1:
|
||||
# everything is noise.
|
||||
core_samples, labels = dbscan(X, algorithm=algorithm, eps=1, min_samples=4)
|
||||
assert_array_equal(core_samples, [])
|
||||
assert_array_equal(labels, np.full(n_samples, -1.0))
|
||||
|
||||
|
||||
def test_dbscan_precomputed_metric_with_degenerate_input_arrays():
|
||||
# see https://github.com/scikit-learn/scikit-learn/issues/4641 for
|
||||
# more details
|
||||
X = np.eye(10)
|
||||
labels = DBSCAN(eps=0.5, metric="precomputed").fit(X).labels_
|
||||
assert len(set(labels)) == 1
|
||||
|
||||
X = np.zeros((10, 10))
|
||||
labels = DBSCAN(eps=0.5, metric="precomputed").fit(X).labels_
|
||||
assert len(set(labels)) == 1
|
||||
|
||||
|
||||
def test_dbscan_precomputed_metric_with_initial_rows_zero():
|
||||
# sample matrix with initial two row all zero
|
||||
ar = np.array(
|
||||
[
|
||||
[0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0],
|
||||
[0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0],
|
||||
[0.0, 0.0, 0.0, 0.0, 0.1, 0.0, 0.0],
|
||||
[0.0, 0.0, 0.0, 0.0, 0.1, 0.0, 0.0],
|
||||
[0.0, 0.0, 0.1, 0.1, 0.0, 0.0, 0.3],
|
||||
[0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.1],
|
||||
[0.0, 0.0, 0.0, 0.0, 0.3, 0.1, 0.0],
|
||||
]
|
||||
)
|
||||
matrix = sparse.csr_matrix(ar)
|
||||
labels = DBSCAN(eps=0.2, metric="precomputed", min_samples=2).fit(matrix).labels_
|
||||
assert_array_equal(labels, [-1, -1, 0, 0, 0, 1, 1])
|
||||
|
||||
|
||||
@pytest.mark.parametrize(
|
||||
"params, err_type, err_msg",
|
||||
[
|
||||
({"eps": -1.0}, ValueError, "eps == -1.0, must be > 0.0."),
|
||||
({"eps": 0.0}, ValueError, "eps == 0.0, must be > 0.0."),
|
||||
({"min_samples": 0}, ValueError, "min_samples == 0, must be >= 1."),
|
||||
(
|
||||
{"min_samples": 1.5},
|
||||
TypeError,
|
||||
"min_samples must be an instance of int, not float.",
|
||||
),
|
||||
({"min_samples": -2}, ValueError, "min_samples == -2, must be >= 1."),
|
||||
({"leaf_size": 0}, ValueError, "leaf_size == 0, must be >= 1."),
|
||||
(
|
||||
{"leaf_size": 2.5},
|
||||
TypeError,
|
||||
"leaf_size must be an instance of int, not float.",
|
||||
),
|
||||
({"leaf_size": -3}, ValueError, "leaf_size == -3, must be >= 1."),
|
||||
({"p": -2}, ValueError, "p == -2, must be >= 0.0."),
|
||||
(
|
||||
{"n_jobs": 2.5},
|
||||
TypeError,
|
||||
"n_jobs must be an instance of int, not float.",
|
||||
),
|
||||
],
|
||||
)
|
||||
def test_dbscan_params_validation(params, err_type, err_msg):
|
||||
"""Check the parameters validation in `DBSCAN`."""
|
||||
with pytest.raises(err_type, match=err_msg):
|
||||
DBSCAN(**params).fit(X)
|
||||
@@ -0,0 +1,55 @@
|
||||
"""
|
||||
Tests for sklearn.cluster._feature_agglomeration
|
||||
"""
|
||||
# Authors: Sergul Aydore 2017
|
||||
import numpy as np
|
||||
|
||||
from numpy.testing import assert_array_equal
|
||||
from sklearn.cluster import FeatureAgglomeration
|
||||
from sklearn.utils._testing import assert_array_almost_equal
|
||||
from sklearn.datasets import make_blobs
|
||||
|
||||
|
||||
def test_feature_agglomeration():
|
||||
n_clusters = 1
|
||||
X = np.array([0, 0, 1]).reshape(1, 3) # (n_samples, n_features)
|
||||
|
||||
agglo_mean = FeatureAgglomeration(n_clusters=n_clusters, pooling_func=np.mean)
|
||||
agglo_median = FeatureAgglomeration(n_clusters=n_clusters, pooling_func=np.median)
|
||||
agglo_mean.fit(X)
|
||||
agglo_median.fit(X)
|
||||
|
||||
assert np.size(np.unique(agglo_mean.labels_)) == n_clusters
|
||||
assert np.size(np.unique(agglo_median.labels_)) == n_clusters
|
||||
assert np.size(agglo_mean.labels_) == X.shape[1]
|
||||
assert np.size(agglo_median.labels_) == X.shape[1]
|
||||
|
||||
# Test transform
|
||||
Xt_mean = agglo_mean.transform(X)
|
||||
Xt_median = agglo_median.transform(X)
|
||||
assert Xt_mean.shape[1] == n_clusters
|
||||
assert Xt_median.shape[1] == n_clusters
|
||||
assert Xt_mean == np.array([1 / 3.0])
|
||||
assert Xt_median == np.array([0.0])
|
||||
|
||||
# Test inverse transform
|
||||
X_full_mean = agglo_mean.inverse_transform(Xt_mean)
|
||||
X_full_median = agglo_median.inverse_transform(Xt_median)
|
||||
assert np.unique(X_full_mean[0]).size == n_clusters
|
||||
assert np.unique(X_full_median[0]).size == n_clusters
|
||||
|
||||
assert_array_almost_equal(agglo_mean.transform(X_full_mean), Xt_mean)
|
||||
assert_array_almost_equal(agglo_median.transform(X_full_median), Xt_median)
|
||||
|
||||
|
||||
def test_feature_agglomeration_feature_names_out():
|
||||
"""Check `get_feature_names_out` for `FeatureAgglomeration`."""
|
||||
X, _ = make_blobs(n_features=6, random_state=0)
|
||||
agglo = FeatureAgglomeration(n_clusters=3)
|
||||
agglo.fit(X)
|
||||
n_clusters = agglo.n_clusters_
|
||||
|
||||
names_out = agglo.get_feature_names_out()
|
||||
assert_array_equal(
|
||||
[f"featureagglomeration{i}" for i in range(n_clusters)], names_out
|
||||
)
|
||||
@@ -0,0 +1,918 @@
|
||||
"""
|
||||
Several basic tests for hierarchical clustering procedures
|
||||
|
||||
"""
|
||||
# Authors: Vincent Michel, 2010, Gael Varoquaux 2012,
|
||||
# Matteo Visconti di Oleggio Castello 2014
|
||||
# License: BSD 3 clause
|
||||
import itertools
|
||||
from tempfile import mkdtemp
|
||||
import shutil
|
||||
import pytest
|
||||
from functools import partial
|
||||
|
||||
import numpy as np
|
||||
from scipy import sparse
|
||||
from scipy.cluster import hierarchy
|
||||
from scipy.sparse.csgraph import connected_components
|
||||
|
||||
from sklearn.metrics.cluster import adjusted_rand_score
|
||||
from sklearn.metrics.tests.test_dist_metrics import METRICS_DEFAULT_PARAMS
|
||||
from sklearn.utils._testing import assert_almost_equal, create_memmap_backed_data
|
||||
from sklearn.utils._testing import assert_array_almost_equal
|
||||
from sklearn.utils._testing import ignore_warnings
|
||||
|
||||
from sklearn.cluster import ward_tree
|
||||
from sklearn.cluster import AgglomerativeClustering, FeatureAgglomeration
|
||||
from sklearn.cluster._agglomerative import (
|
||||
_hc_cut,
|
||||
_TREE_BUILDERS,
|
||||
linkage_tree,
|
||||
_fix_connectivity,
|
||||
)
|
||||
from sklearn.feature_extraction.image import grid_to_graph
|
||||
from sklearn.metrics import DistanceMetric
|
||||
from sklearn.metrics.pairwise import (
|
||||
PAIRED_DISTANCES,
|
||||
cosine_distances,
|
||||
manhattan_distances,
|
||||
pairwise_distances,
|
||||
)
|
||||
from sklearn.metrics.cluster import normalized_mutual_info_score
|
||||
from sklearn.neighbors import kneighbors_graph
|
||||
from sklearn.cluster._hierarchical_fast import (
|
||||
average_merge,
|
||||
max_merge,
|
||||
mst_linkage_core,
|
||||
)
|
||||
from sklearn.utils._fast_dict import IntFloatDict
|
||||
from sklearn.utils._testing import assert_array_equal
|
||||
from sklearn.datasets import make_moons, make_circles
|
||||
|
||||
|
||||
def test_linkage_misc():
|
||||
# Misc tests on linkage
|
||||
rng = np.random.RandomState(42)
|
||||
X = rng.normal(size=(5, 5))
|
||||
with pytest.raises(ValueError):
|
||||
AgglomerativeClustering(linkage="foo").fit(X)
|
||||
|
||||
with pytest.raises(ValueError):
|
||||
linkage_tree(X, linkage="foo")
|
||||
|
||||
with pytest.raises(ValueError):
|
||||
linkage_tree(X, connectivity=np.ones((4, 4)))
|
||||
|
||||
# Smoke test FeatureAgglomeration
|
||||
FeatureAgglomeration().fit(X)
|
||||
|
||||
# test hierarchical clustering on a precomputed distances matrix
|
||||
dis = cosine_distances(X)
|
||||
|
||||
res = linkage_tree(dis, affinity="precomputed")
|
||||
assert_array_equal(res[0], linkage_tree(X, affinity="cosine")[0])
|
||||
|
||||
# test hierarchical clustering on a precomputed distances matrix
|
||||
res = linkage_tree(X, affinity=manhattan_distances)
|
||||
assert_array_equal(res[0], linkage_tree(X, affinity="manhattan")[0])
|
||||
|
||||
|
||||
def test_structured_linkage_tree():
|
||||
# Check that we obtain the correct solution for structured linkage trees.
|
||||
rng = np.random.RandomState(0)
|
||||
mask = np.ones([10, 10], dtype=bool)
|
||||
# Avoiding a mask with only 'True' entries
|
||||
mask[4:7, 4:7] = 0
|
||||
X = rng.randn(50, 100)
|
||||
connectivity = grid_to_graph(*mask.shape)
|
||||
for tree_builder in _TREE_BUILDERS.values():
|
||||
children, n_components, n_leaves, parent = tree_builder(
|
||||
X.T, connectivity=connectivity
|
||||
)
|
||||
n_nodes = 2 * X.shape[1] - 1
|
||||
assert len(children) + n_leaves == n_nodes
|
||||
# Check that ward_tree raises a ValueError with a connectivity matrix
|
||||
# of the wrong shape
|
||||
with pytest.raises(ValueError):
|
||||
tree_builder(X.T, connectivity=np.ones((4, 4)))
|
||||
# Check that fitting with no samples raises an error
|
||||
with pytest.raises(ValueError):
|
||||
tree_builder(X.T[:0], connectivity=connectivity)
|
||||
|
||||
|
||||
def test_unstructured_linkage_tree():
|
||||
# Check that we obtain the correct solution for unstructured linkage trees.
|
||||
rng = np.random.RandomState(0)
|
||||
X = rng.randn(50, 100)
|
||||
for this_X in (X, X[0]):
|
||||
# With specified a number of clusters just for the sake of
|
||||
# raising a warning and testing the warning code
|
||||
with ignore_warnings():
|
||||
with pytest.warns(UserWarning):
|
||||
children, n_nodes, n_leaves, parent = ward_tree(this_X.T, n_clusters=10)
|
||||
n_nodes = 2 * X.shape[1] - 1
|
||||
assert len(children) + n_leaves == n_nodes
|
||||
|
||||
for tree_builder in _TREE_BUILDERS.values():
|
||||
for this_X in (X, X[0]):
|
||||
with ignore_warnings():
|
||||
with pytest.warns(UserWarning):
|
||||
children, n_nodes, n_leaves, parent = tree_builder(
|
||||
this_X.T, n_clusters=10
|
||||
)
|
||||
n_nodes = 2 * X.shape[1] - 1
|
||||
assert len(children) + n_leaves == n_nodes
|
||||
|
||||
|
||||
def test_height_linkage_tree():
|
||||
# Check that the height of the results of linkage tree is sorted.
|
||||
rng = np.random.RandomState(0)
|
||||
mask = np.ones([10, 10], dtype=bool)
|
||||
X = rng.randn(50, 100)
|
||||
connectivity = grid_to_graph(*mask.shape)
|
||||
for linkage_func in _TREE_BUILDERS.values():
|
||||
children, n_nodes, n_leaves, parent = linkage_func(
|
||||
X.T, connectivity=connectivity
|
||||
)
|
||||
n_nodes = 2 * X.shape[1] - 1
|
||||
assert len(children) + n_leaves == n_nodes
|
||||
|
||||
|
||||
def test_agglomerative_clustering_wrong_arg_memory():
|
||||
# Test either if an error is raised when memory is not
|
||||
# either a str or a joblib.Memory instance
|
||||
rng = np.random.RandomState(0)
|
||||
n_samples = 100
|
||||
X = rng.randn(n_samples, 50)
|
||||
memory = 5
|
||||
clustering = AgglomerativeClustering(memory=memory)
|
||||
with pytest.raises(ValueError):
|
||||
clustering.fit(X)
|
||||
|
||||
|
||||
def test_zero_cosine_linkage_tree():
|
||||
# Check that zero vectors in X produce an error when
|
||||
# 'cosine' affinity is used
|
||||
X = np.array([[0, 1], [0, 0]])
|
||||
msg = "Cosine affinity cannot be used when X contains zero vectors"
|
||||
with pytest.raises(ValueError, match=msg):
|
||||
linkage_tree(X, affinity="cosine")
|
||||
|
||||
|
||||
@pytest.mark.parametrize("n_clusters, distance_threshold", [(None, 0.5), (10, None)])
|
||||
@pytest.mark.parametrize("compute_distances", [True, False])
|
||||
@pytest.mark.parametrize("linkage", ["ward", "complete", "average", "single"])
|
||||
def test_agglomerative_clustering_distances(
|
||||
n_clusters, compute_distances, distance_threshold, linkage
|
||||
):
|
||||
# Check that when `compute_distances` is True or `distance_threshold` is
|
||||
# given, the fitted model has an attribute `distances_`.
|
||||
rng = np.random.RandomState(0)
|
||||
mask = np.ones([10, 10], dtype=bool)
|
||||
n_samples = 100
|
||||
X = rng.randn(n_samples, 50)
|
||||
connectivity = grid_to_graph(*mask.shape)
|
||||
|
||||
clustering = AgglomerativeClustering(
|
||||
n_clusters=n_clusters,
|
||||
connectivity=connectivity,
|
||||
linkage=linkage,
|
||||
distance_threshold=distance_threshold,
|
||||
compute_distances=compute_distances,
|
||||
)
|
||||
clustering.fit(X)
|
||||
if compute_distances or (distance_threshold is not None):
|
||||
assert hasattr(clustering, "distances_")
|
||||
n_children = clustering.children_.shape[0]
|
||||
n_nodes = n_children + 1
|
||||
assert clustering.distances_.shape == (n_nodes - 1,)
|
||||
else:
|
||||
assert not hasattr(clustering, "distances_")
|
||||
|
||||
|
||||
def test_agglomerative_clustering():
|
||||
# Check that we obtain the correct number of clusters with
|
||||
# agglomerative clustering.
|
||||
rng = np.random.RandomState(0)
|
||||
mask = np.ones([10, 10], dtype=bool)
|
||||
n_samples = 100
|
||||
X = rng.randn(n_samples, 50)
|
||||
connectivity = grid_to_graph(*mask.shape)
|
||||
for linkage in ("ward", "complete", "average", "single"):
|
||||
clustering = AgglomerativeClustering(
|
||||
n_clusters=10, connectivity=connectivity, linkage=linkage
|
||||
)
|
||||
clustering.fit(X)
|
||||
# test caching
|
||||
try:
|
||||
tempdir = mkdtemp()
|
||||
clustering = AgglomerativeClustering(
|
||||
n_clusters=10,
|
||||
connectivity=connectivity,
|
||||
memory=tempdir,
|
||||
linkage=linkage,
|
||||
)
|
||||
clustering.fit(X)
|
||||
labels = clustering.labels_
|
||||
assert np.size(np.unique(labels)) == 10
|
||||
finally:
|
||||
shutil.rmtree(tempdir)
|
||||
# Turn caching off now
|
||||
clustering = AgglomerativeClustering(
|
||||
n_clusters=10, connectivity=connectivity, linkage=linkage
|
||||
)
|
||||
# Check that we obtain the same solution with early-stopping of the
|
||||
# tree building
|
||||
clustering.compute_full_tree = False
|
||||
clustering.fit(X)
|
||||
assert_almost_equal(normalized_mutual_info_score(clustering.labels_, labels), 1)
|
||||
clustering.connectivity = None
|
||||
clustering.fit(X)
|
||||
assert np.size(np.unique(clustering.labels_)) == 10
|
||||
# Check that we raise a TypeError on dense matrices
|
||||
clustering = AgglomerativeClustering(
|
||||
n_clusters=10,
|
||||
connectivity=sparse.lil_matrix(connectivity.toarray()[:10, :10]),
|
||||
linkage=linkage,
|
||||
)
|
||||
with pytest.raises(ValueError):
|
||||
clustering.fit(X)
|
||||
|
||||
# Test that using ward with another metric than euclidean raises an
|
||||
# exception
|
||||
clustering = AgglomerativeClustering(
|
||||
n_clusters=10,
|
||||
connectivity=connectivity.toarray(),
|
||||
affinity="manhattan",
|
||||
linkage="ward",
|
||||
)
|
||||
with pytest.raises(ValueError):
|
||||
clustering.fit(X)
|
||||
|
||||
# Test using another metric than euclidean works with linkage complete
|
||||
for affinity in PAIRED_DISTANCES.keys():
|
||||
# Compare our (structured) implementation to scipy
|
||||
clustering = AgglomerativeClustering(
|
||||
n_clusters=10,
|
||||
connectivity=np.ones((n_samples, n_samples)),
|
||||
affinity=affinity,
|
||||
linkage="complete",
|
||||
)
|
||||
clustering.fit(X)
|
||||
clustering2 = AgglomerativeClustering(
|
||||
n_clusters=10, connectivity=None, affinity=affinity, linkage="complete"
|
||||
)
|
||||
clustering2.fit(X)
|
||||
assert_almost_equal(
|
||||
normalized_mutual_info_score(clustering2.labels_, clustering.labels_), 1
|
||||
)
|
||||
|
||||
# Test that using a distance matrix (affinity = 'precomputed') has same
|
||||
# results (with connectivity constraints)
|
||||
clustering = AgglomerativeClustering(
|
||||
n_clusters=10, connectivity=connectivity, linkage="complete"
|
||||
)
|
||||
clustering.fit(X)
|
||||
X_dist = pairwise_distances(X)
|
||||
clustering2 = AgglomerativeClustering(
|
||||
n_clusters=10,
|
||||
connectivity=connectivity,
|
||||
affinity="precomputed",
|
||||
linkage="complete",
|
||||
)
|
||||
clustering2.fit(X_dist)
|
||||
assert_array_equal(clustering.labels_, clustering2.labels_)
|
||||
|
||||
|
||||
def test_agglomerative_clustering_memory_mapped():
|
||||
"""AgglomerativeClustering must work on mem-mapped dataset.
|
||||
|
||||
Non-regression test for issue #19875.
|
||||
"""
|
||||
rng = np.random.RandomState(0)
|
||||
Xmm = create_memmap_backed_data(rng.randn(50, 100))
|
||||
AgglomerativeClustering(affinity="euclidean", linkage="single").fit(Xmm)
|
||||
|
||||
|
||||
def test_ward_agglomeration():
|
||||
# Check that we obtain the correct solution in a simplistic case
|
||||
rng = np.random.RandomState(0)
|
||||
mask = np.ones([10, 10], dtype=bool)
|
||||
X = rng.randn(50, 100)
|
||||
connectivity = grid_to_graph(*mask.shape)
|
||||
agglo = FeatureAgglomeration(n_clusters=5, connectivity=connectivity)
|
||||
agglo.fit(X)
|
||||
assert np.size(np.unique(agglo.labels_)) == 5
|
||||
|
||||
X_red = agglo.transform(X)
|
||||
assert X_red.shape[1] == 5
|
||||
X_full = agglo.inverse_transform(X_red)
|
||||
assert np.unique(X_full[0]).size == 5
|
||||
assert_array_almost_equal(agglo.transform(X_full), X_red)
|
||||
|
||||
# Check that fitting with no samples raises a ValueError
|
||||
with pytest.raises(ValueError):
|
||||
agglo.fit(X[:0])
|
||||
|
||||
|
||||
def test_single_linkage_clustering():
|
||||
# Check that we get the correct result in two emblematic cases
|
||||
moons, moon_labels = make_moons(noise=0.05, random_state=42)
|
||||
clustering = AgglomerativeClustering(n_clusters=2, linkage="single")
|
||||
clustering.fit(moons)
|
||||
assert_almost_equal(
|
||||
normalized_mutual_info_score(clustering.labels_, moon_labels), 1
|
||||
)
|
||||
|
||||
circles, circle_labels = make_circles(factor=0.5, noise=0.025, random_state=42)
|
||||
clustering = AgglomerativeClustering(n_clusters=2, linkage="single")
|
||||
clustering.fit(circles)
|
||||
assert_almost_equal(
|
||||
normalized_mutual_info_score(clustering.labels_, circle_labels), 1
|
||||
)
|
||||
|
||||
|
||||
def assess_same_labelling(cut1, cut2):
|
||||
"""Util for comparison with scipy"""
|
||||
co_clust = []
|
||||
for cut in [cut1, cut2]:
|
||||
n = len(cut)
|
||||
k = cut.max() + 1
|
||||
ecut = np.zeros((n, k))
|
||||
ecut[np.arange(n), cut] = 1
|
||||
co_clust.append(np.dot(ecut, ecut.T))
|
||||
assert (co_clust[0] == co_clust[1]).all()
|
||||
|
||||
|
||||
def test_sparse_scikit_vs_scipy():
|
||||
# Test scikit linkage with full connectivity (i.e. unstructured) vs scipy
|
||||
n, p, k = 10, 5, 3
|
||||
rng = np.random.RandomState(0)
|
||||
|
||||
# Not using a lil_matrix here, just to check that non sparse
|
||||
# matrices are well handled
|
||||
connectivity = np.ones((n, n))
|
||||
for linkage in _TREE_BUILDERS.keys():
|
||||
for i in range(5):
|
||||
X = 0.1 * rng.normal(size=(n, p))
|
||||
X -= 4.0 * np.arange(n)[:, np.newaxis]
|
||||
X -= X.mean(axis=1)[:, np.newaxis]
|
||||
|
||||
out = hierarchy.linkage(X, method=linkage)
|
||||
|
||||
children_ = out[:, :2].astype(int, copy=False)
|
||||
children, _, n_leaves, _ = _TREE_BUILDERS[linkage](
|
||||
X, connectivity=connectivity
|
||||
)
|
||||
|
||||
# Sort the order of child nodes per row for consistency
|
||||
children.sort(axis=1)
|
||||
assert_array_equal(
|
||||
children,
|
||||
children_,
|
||||
"linkage tree differs from scipy impl for linkage: " + linkage,
|
||||
)
|
||||
|
||||
cut = _hc_cut(k, children, n_leaves)
|
||||
cut_ = _hc_cut(k, children_, n_leaves)
|
||||
assess_same_labelling(cut, cut_)
|
||||
|
||||
# Test error management in _hc_cut
|
||||
with pytest.raises(ValueError):
|
||||
_hc_cut(n_leaves + 1, children, n_leaves)
|
||||
|
||||
|
||||
# Make sure our custom mst_linkage_core gives
|
||||
# the same results as scipy's builtin
|
||||
@pytest.mark.parametrize("seed", range(5))
|
||||
def test_vector_scikit_single_vs_scipy_single(seed):
|
||||
n_samples, n_features, n_clusters = 10, 5, 3
|
||||
rng = np.random.RandomState(seed)
|
||||
X = 0.1 * rng.normal(size=(n_samples, n_features))
|
||||
X -= 4.0 * np.arange(n_samples)[:, np.newaxis]
|
||||
X -= X.mean(axis=1)[:, np.newaxis]
|
||||
|
||||
out = hierarchy.linkage(X, method="single")
|
||||
children_scipy = out[:, :2].astype(int)
|
||||
|
||||
children, _, n_leaves, _ = _TREE_BUILDERS["single"](X)
|
||||
|
||||
# Sort the order of child nodes per row for consistency
|
||||
children.sort(axis=1)
|
||||
assert_array_equal(
|
||||
children,
|
||||
children_scipy,
|
||||
"linkage tree differs from scipy impl for single linkage.",
|
||||
)
|
||||
|
||||
cut = _hc_cut(n_clusters, children, n_leaves)
|
||||
cut_scipy = _hc_cut(n_clusters, children_scipy, n_leaves)
|
||||
assess_same_labelling(cut, cut_scipy)
|
||||
|
||||
|
||||
# TODO: Remove filterwarnings in 1.3 when wminkowski is removed
|
||||
@pytest.mark.filterwarnings("ignore:WMinkowskiDistance:FutureWarning:sklearn")
|
||||
@pytest.mark.parametrize("metric_param_grid", METRICS_DEFAULT_PARAMS)
|
||||
def test_mst_linkage_core_memory_mapped(metric_param_grid):
|
||||
"""The MST-LINKAGE-CORE algorithm must work on mem-mapped dataset.
|
||||
|
||||
Non-regression test for issue #19875.
|
||||
"""
|
||||
rng = np.random.RandomState(seed=1)
|
||||
X = rng.normal(size=(20, 4))
|
||||
Xmm = create_memmap_backed_data(X)
|
||||
metric, param_grid = metric_param_grid
|
||||
keys = param_grid.keys()
|
||||
for vals in itertools.product(*param_grid.values()):
|
||||
kwargs = dict(zip(keys, vals))
|
||||
distance_metric = DistanceMetric.get_metric(metric, **kwargs)
|
||||
mst = mst_linkage_core(X, distance_metric)
|
||||
mst_mm = mst_linkage_core(Xmm, distance_metric)
|
||||
np.testing.assert_equal(mst, mst_mm)
|
||||
|
||||
|
||||
def test_identical_points():
|
||||
# Ensure identical points are handled correctly when using mst with
|
||||
# a sparse connectivity matrix
|
||||
X = np.array([[0, 0, 0], [0, 0, 0], [1, 1, 1], [1, 1, 1], [2, 2, 2], [2, 2, 2]])
|
||||
true_labels = np.array([0, 0, 1, 1, 2, 2])
|
||||
connectivity = kneighbors_graph(X, n_neighbors=3, include_self=False)
|
||||
connectivity = 0.5 * (connectivity + connectivity.T)
|
||||
connectivity, n_components = _fix_connectivity(X, connectivity, "euclidean")
|
||||
|
||||
for linkage in ("single", "average", "average", "ward"):
|
||||
clustering = AgglomerativeClustering(
|
||||
n_clusters=3, linkage=linkage, connectivity=connectivity
|
||||
)
|
||||
clustering.fit(X)
|
||||
|
||||
assert_almost_equal(
|
||||
normalized_mutual_info_score(clustering.labels_, true_labels), 1
|
||||
)
|
||||
|
||||
|
||||
def test_connectivity_propagation():
|
||||
# Check that connectivity in the ward tree is propagated correctly during
|
||||
# merging.
|
||||
X = np.array(
|
||||
[
|
||||
(0.014, 0.120),
|
||||
(0.014, 0.099),
|
||||
(0.014, 0.097),
|
||||
(0.017, 0.153),
|
||||
(0.017, 0.153),
|
||||
(0.018, 0.153),
|
||||
(0.018, 0.153),
|
||||
(0.018, 0.153),
|
||||
(0.018, 0.153),
|
||||
(0.018, 0.153),
|
||||
(0.018, 0.153),
|
||||
(0.018, 0.153),
|
||||
(0.018, 0.152),
|
||||
(0.018, 0.149),
|
||||
(0.018, 0.144),
|
||||
]
|
||||
)
|
||||
connectivity = kneighbors_graph(X, 10, include_self=False)
|
||||
ward = AgglomerativeClustering(
|
||||
n_clusters=4, connectivity=connectivity, linkage="ward"
|
||||
)
|
||||
# If changes are not propagated correctly, fit crashes with an
|
||||
# IndexError
|
||||
ward.fit(X)
|
||||
|
||||
|
||||
def test_ward_tree_children_order():
|
||||
# Check that children are ordered in the same way for both structured and
|
||||
# unstructured versions of ward_tree.
|
||||
|
||||
# test on five random datasets
|
||||
n, p = 10, 5
|
||||
rng = np.random.RandomState(0)
|
||||
|
||||
connectivity = np.ones((n, n))
|
||||
for i in range(5):
|
||||
X = 0.1 * rng.normal(size=(n, p))
|
||||
X -= 4.0 * np.arange(n)[:, np.newaxis]
|
||||
X -= X.mean(axis=1)[:, np.newaxis]
|
||||
|
||||
out_unstructured = ward_tree(X)
|
||||
out_structured = ward_tree(X, connectivity=connectivity)
|
||||
|
||||
assert_array_equal(out_unstructured[0], out_structured[0])
|
||||
|
||||
|
||||
def test_ward_linkage_tree_return_distance():
|
||||
# Test return_distance option on linkage and ward trees
|
||||
|
||||
# test that return_distance when set true, gives same
|
||||
# output on both structured and unstructured clustering.
|
||||
n, p = 10, 5
|
||||
rng = np.random.RandomState(0)
|
||||
|
||||
connectivity = np.ones((n, n))
|
||||
for i in range(5):
|
||||
X = 0.1 * rng.normal(size=(n, p))
|
||||
X -= 4.0 * np.arange(n)[:, np.newaxis]
|
||||
X -= X.mean(axis=1)[:, np.newaxis]
|
||||
|
||||
out_unstructured = ward_tree(X, return_distance=True)
|
||||
out_structured = ward_tree(X, connectivity=connectivity, return_distance=True)
|
||||
|
||||
# get children
|
||||
children_unstructured = out_unstructured[0]
|
||||
children_structured = out_structured[0]
|
||||
|
||||
# check if we got the same clusters
|
||||
assert_array_equal(children_unstructured, children_structured)
|
||||
|
||||
# check if the distances are the same
|
||||
dist_unstructured = out_unstructured[-1]
|
||||
dist_structured = out_structured[-1]
|
||||
|
||||
assert_array_almost_equal(dist_unstructured, dist_structured)
|
||||
|
||||
for linkage in ["average", "complete", "single"]:
|
||||
structured_items = linkage_tree(
|
||||
X, connectivity=connectivity, linkage=linkage, return_distance=True
|
||||
)[-1]
|
||||
unstructured_items = linkage_tree(X, linkage=linkage, return_distance=True)[
|
||||
-1
|
||||
]
|
||||
structured_dist = structured_items[-1]
|
||||
unstructured_dist = unstructured_items[-1]
|
||||
structured_children = structured_items[0]
|
||||
unstructured_children = unstructured_items[0]
|
||||
assert_array_almost_equal(structured_dist, unstructured_dist)
|
||||
assert_array_almost_equal(structured_children, unstructured_children)
|
||||
|
||||
# test on the following dataset where we know the truth
|
||||
# taken from scipy/cluster/tests/hierarchy_test_data.py
|
||||
X = np.array(
|
||||
[
|
||||
[1.43054825, -7.5693489],
|
||||
[6.95887839, 6.82293382],
|
||||
[2.87137846, -9.68248579],
|
||||
[7.87974764, -6.05485803],
|
||||
[8.24018364, -6.09495602],
|
||||
[7.39020262, 8.54004355],
|
||||
]
|
||||
)
|
||||
# truth
|
||||
linkage_X_ward = np.array(
|
||||
[
|
||||
[3.0, 4.0, 0.36265956, 2.0],
|
||||
[1.0, 5.0, 1.77045373, 2.0],
|
||||
[0.0, 2.0, 2.55760419, 2.0],
|
||||
[6.0, 8.0, 9.10208346, 4.0],
|
||||
[7.0, 9.0, 24.7784379, 6.0],
|
||||
]
|
||||
)
|
||||
|
||||
linkage_X_complete = np.array(
|
||||
[
|
||||
[3.0, 4.0, 0.36265956, 2.0],
|
||||
[1.0, 5.0, 1.77045373, 2.0],
|
||||
[0.0, 2.0, 2.55760419, 2.0],
|
||||
[6.0, 8.0, 6.96742194, 4.0],
|
||||
[7.0, 9.0, 18.77445997, 6.0],
|
||||
]
|
||||
)
|
||||
|
||||
linkage_X_average = np.array(
|
||||
[
|
||||
[3.0, 4.0, 0.36265956, 2.0],
|
||||
[1.0, 5.0, 1.77045373, 2.0],
|
||||
[0.0, 2.0, 2.55760419, 2.0],
|
||||
[6.0, 8.0, 6.55832839, 4.0],
|
||||
[7.0, 9.0, 15.44089605, 6.0],
|
||||
]
|
||||
)
|
||||
|
||||
n_samples, n_features = np.shape(X)
|
||||
connectivity_X = np.ones((n_samples, n_samples))
|
||||
|
||||
out_X_unstructured = ward_tree(X, return_distance=True)
|
||||
out_X_structured = ward_tree(X, connectivity=connectivity_X, return_distance=True)
|
||||
|
||||
# check that the labels are the same
|
||||
assert_array_equal(linkage_X_ward[:, :2], out_X_unstructured[0])
|
||||
assert_array_equal(linkage_X_ward[:, :2], out_X_structured[0])
|
||||
|
||||
# check that the distances are correct
|
||||
assert_array_almost_equal(linkage_X_ward[:, 2], out_X_unstructured[4])
|
||||
assert_array_almost_equal(linkage_X_ward[:, 2], out_X_structured[4])
|
||||
|
||||
linkage_options = ["complete", "average", "single"]
|
||||
X_linkage_truth = [linkage_X_complete, linkage_X_average]
|
||||
for linkage, X_truth in zip(linkage_options, X_linkage_truth):
|
||||
out_X_unstructured = linkage_tree(X, return_distance=True, linkage=linkage)
|
||||
out_X_structured = linkage_tree(
|
||||
X, connectivity=connectivity_X, linkage=linkage, return_distance=True
|
||||
)
|
||||
|
||||
# check that the labels are the same
|
||||
assert_array_equal(X_truth[:, :2], out_X_unstructured[0])
|
||||
assert_array_equal(X_truth[:, :2], out_X_structured[0])
|
||||
|
||||
# check that the distances are correct
|
||||
assert_array_almost_equal(X_truth[:, 2], out_X_unstructured[4])
|
||||
assert_array_almost_equal(X_truth[:, 2], out_X_structured[4])
|
||||
|
||||
|
||||
def test_connectivity_fixing_non_lil():
|
||||
# Check non regression of a bug if a non item assignable connectivity is
|
||||
# provided with more than one component.
|
||||
# create dummy data
|
||||
x = np.array([[0, 0], [1, 1]])
|
||||
# create a mask with several components to force connectivity fixing
|
||||
m = np.array([[True, False], [False, True]])
|
||||
c = grid_to_graph(n_x=2, n_y=2, mask=m)
|
||||
w = AgglomerativeClustering(connectivity=c, linkage="ward")
|
||||
with pytest.warns(UserWarning):
|
||||
w.fit(x)
|
||||
|
||||
|
||||
def test_int_float_dict():
|
||||
rng = np.random.RandomState(0)
|
||||
keys = np.unique(rng.randint(100, size=10).astype(np.intp, copy=False))
|
||||
values = rng.rand(len(keys))
|
||||
|
||||
d = IntFloatDict(keys, values)
|
||||
for key, value in zip(keys, values):
|
||||
assert d[key] == value
|
||||
|
||||
other_keys = np.arange(50, dtype=np.intp)[::2]
|
||||
other_values = np.full(50, 0.5)[::2]
|
||||
other = IntFloatDict(other_keys, other_values)
|
||||
# Complete smoke test
|
||||
max_merge(d, other, mask=np.ones(100, dtype=np.intp), n_a=1, n_b=1)
|
||||
average_merge(d, other, mask=np.ones(100, dtype=np.intp), n_a=1, n_b=1)
|
||||
|
||||
|
||||
def test_connectivity_callable():
|
||||
rng = np.random.RandomState(0)
|
||||
X = rng.rand(20, 5)
|
||||
connectivity = kneighbors_graph(X, 3, include_self=False)
|
||||
aglc1 = AgglomerativeClustering(connectivity=connectivity)
|
||||
aglc2 = AgglomerativeClustering(
|
||||
connectivity=partial(kneighbors_graph, n_neighbors=3, include_self=False)
|
||||
)
|
||||
aglc1.fit(X)
|
||||
aglc2.fit(X)
|
||||
assert_array_equal(aglc1.labels_, aglc2.labels_)
|
||||
|
||||
|
||||
def test_connectivity_ignores_diagonal():
|
||||
rng = np.random.RandomState(0)
|
||||
X = rng.rand(20, 5)
|
||||
connectivity = kneighbors_graph(X, 3, include_self=False)
|
||||
connectivity_include_self = kneighbors_graph(X, 3, include_self=True)
|
||||
aglc1 = AgglomerativeClustering(connectivity=connectivity)
|
||||
aglc2 = AgglomerativeClustering(connectivity=connectivity_include_self)
|
||||
aglc1.fit(X)
|
||||
aglc2.fit(X)
|
||||
assert_array_equal(aglc1.labels_, aglc2.labels_)
|
||||
|
||||
|
||||
def test_compute_full_tree():
|
||||
# Test that the full tree is computed if n_clusters is small
|
||||
rng = np.random.RandomState(0)
|
||||
X = rng.randn(10, 2)
|
||||
connectivity = kneighbors_graph(X, 5, include_self=False)
|
||||
|
||||
# When n_clusters is less, the full tree should be built
|
||||
# that is the number of merges should be n_samples - 1
|
||||
agc = AgglomerativeClustering(n_clusters=2, connectivity=connectivity)
|
||||
agc.fit(X)
|
||||
n_samples = X.shape[0]
|
||||
n_nodes = agc.children_.shape[0]
|
||||
assert n_nodes == n_samples - 1
|
||||
|
||||
# When n_clusters is large, greater than max of 100 and 0.02 * n_samples.
|
||||
# we should stop when there are n_clusters.
|
||||
n_clusters = 101
|
||||
X = rng.randn(200, 2)
|
||||
connectivity = kneighbors_graph(X, 10, include_self=False)
|
||||
agc = AgglomerativeClustering(n_clusters=n_clusters, connectivity=connectivity)
|
||||
agc.fit(X)
|
||||
n_samples = X.shape[0]
|
||||
n_nodes = agc.children_.shape[0]
|
||||
assert n_nodes == n_samples - n_clusters
|
||||
|
||||
|
||||
def test_n_components():
|
||||
# Test n_components returned by linkage, average and ward tree
|
||||
rng = np.random.RandomState(0)
|
||||
X = rng.rand(5, 5)
|
||||
|
||||
# Connectivity matrix having five components.
|
||||
connectivity = np.eye(5)
|
||||
|
||||
for linkage_func in _TREE_BUILDERS.values():
|
||||
assert ignore_warnings(linkage_func)(X, connectivity=connectivity)[1] == 5
|
||||
|
||||
|
||||
def test_agg_n_clusters():
|
||||
# Test that an error is raised when n_clusters <= 0
|
||||
|
||||
rng = np.random.RandomState(0)
|
||||
X = rng.rand(20, 10)
|
||||
for n_clus in [-1, 0]:
|
||||
agc = AgglomerativeClustering(n_clusters=n_clus)
|
||||
msg = "n_clusters should be an integer greater than 0. %s was provided." % str(
|
||||
agc.n_clusters
|
||||
)
|
||||
with pytest.raises(ValueError, match=msg):
|
||||
agc.fit(X)
|
||||
|
||||
|
||||
def test_affinity_passed_to_fix_connectivity():
|
||||
# Test that the affinity parameter is actually passed to the pairwise
|
||||
# function
|
||||
|
||||
size = 2
|
||||
rng = np.random.RandomState(0)
|
||||
X = rng.randn(size, size)
|
||||
mask = np.array([True, False, False, True])
|
||||
|
||||
connectivity = grid_to_graph(n_x=size, n_y=size, mask=mask, return_as=np.ndarray)
|
||||
|
||||
class FakeAffinity:
|
||||
def __init__(self):
|
||||
self.counter = 0
|
||||
|
||||
def increment(self, *args, **kwargs):
|
||||
self.counter += 1
|
||||
return self.counter
|
||||
|
||||
fa = FakeAffinity()
|
||||
|
||||
linkage_tree(X, connectivity=connectivity, affinity=fa.increment)
|
||||
|
||||
assert fa.counter == 3
|
||||
|
||||
|
||||
@pytest.mark.parametrize("linkage", ["ward", "complete", "average"])
|
||||
def test_agglomerative_clustering_with_distance_threshold(linkage):
|
||||
# Check that we obtain the correct number of clusters with
|
||||
# agglomerative clustering with distance_threshold.
|
||||
rng = np.random.RandomState(0)
|
||||
mask = np.ones([10, 10], dtype=bool)
|
||||
n_samples = 100
|
||||
X = rng.randn(n_samples, 50)
|
||||
connectivity = grid_to_graph(*mask.shape)
|
||||
# test when distance threshold is set to 10
|
||||
distance_threshold = 10
|
||||
for conn in [None, connectivity]:
|
||||
clustering = AgglomerativeClustering(
|
||||
n_clusters=None,
|
||||
distance_threshold=distance_threshold,
|
||||
connectivity=conn,
|
||||
linkage=linkage,
|
||||
)
|
||||
clustering.fit(X)
|
||||
clusters_produced = clustering.labels_
|
||||
num_clusters_produced = len(np.unique(clustering.labels_))
|
||||
# test if the clusters produced match the point in the linkage tree
|
||||
# where the distance exceeds the threshold
|
||||
tree_builder = _TREE_BUILDERS[linkage]
|
||||
children, n_components, n_leaves, parent, distances = tree_builder(
|
||||
X, connectivity=conn, n_clusters=None, return_distance=True
|
||||
)
|
||||
num_clusters_at_threshold = (
|
||||
np.count_nonzero(distances >= distance_threshold) + 1
|
||||
)
|
||||
# test number of clusters produced
|
||||
assert num_clusters_at_threshold == num_clusters_produced
|
||||
# test clusters produced
|
||||
clusters_at_threshold = _hc_cut(
|
||||
n_clusters=num_clusters_produced, children=children, n_leaves=n_leaves
|
||||
)
|
||||
assert np.array_equiv(clusters_produced, clusters_at_threshold)
|
||||
|
||||
|
||||
def test_small_distance_threshold():
|
||||
rng = np.random.RandomState(0)
|
||||
n_samples = 10
|
||||
X = rng.randint(-300, 300, size=(n_samples, 3))
|
||||
# this should result in all data in their own clusters, given that
|
||||
# their pairwise distances are bigger than .1 (which may not be the case
|
||||
# with a different random seed).
|
||||
clustering = AgglomerativeClustering(
|
||||
n_clusters=None, distance_threshold=1.0, linkage="single"
|
||||
).fit(X)
|
||||
# check that the pairwise distances are indeed all larger than .1
|
||||
all_distances = pairwise_distances(X, metric="minkowski", p=2)
|
||||
np.fill_diagonal(all_distances, np.inf)
|
||||
assert np.all(all_distances > 0.1)
|
||||
assert clustering.n_clusters_ == n_samples
|
||||
|
||||
|
||||
def test_cluster_distances_with_distance_threshold():
|
||||
rng = np.random.RandomState(0)
|
||||
n_samples = 100
|
||||
X = rng.randint(-10, 10, size=(n_samples, 3))
|
||||
# check the distances within the clusters and with other clusters
|
||||
distance_threshold = 4
|
||||
clustering = AgglomerativeClustering(
|
||||
n_clusters=None, distance_threshold=distance_threshold, linkage="single"
|
||||
).fit(X)
|
||||
labels = clustering.labels_
|
||||
D = pairwise_distances(X, metric="minkowski", p=2)
|
||||
# to avoid taking the 0 diagonal in min()
|
||||
np.fill_diagonal(D, np.inf)
|
||||
for label in np.unique(labels):
|
||||
in_cluster_mask = labels == label
|
||||
max_in_cluster_distance = (
|
||||
D[in_cluster_mask][:, in_cluster_mask].min(axis=0).max()
|
||||
)
|
||||
min_out_cluster_distance = (
|
||||
D[in_cluster_mask][:, ~in_cluster_mask].min(axis=0).min()
|
||||
)
|
||||
# single data point clusters only have that inf diagonal here
|
||||
if in_cluster_mask.sum() > 1:
|
||||
assert max_in_cluster_distance < distance_threshold
|
||||
assert min_out_cluster_distance >= distance_threshold
|
||||
|
||||
|
||||
@pytest.mark.parametrize("linkage", ["ward", "complete", "average"])
|
||||
@pytest.mark.parametrize(
|
||||
("threshold", "y_true"), [(0.5, [1, 0]), (1.0, [1, 0]), (1.5, [0, 0])]
|
||||
)
|
||||
def test_agglomerative_clustering_with_distance_threshold_edge_case(
|
||||
linkage, threshold, y_true
|
||||
):
|
||||
# test boundary case of distance_threshold matching the distance
|
||||
X = [[0], [1]]
|
||||
clusterer = AgglomerativeClustering(
|
||||
n_clusters=None, distance_threshold=threshold, linkage=linkage
|
||||
)
|
||||
y_pred = clusterer.fit_predict(X)
|
||||
assert adjusted_rand_score(y_true, y_pred) == 1
|
||||
|
||||
|
||||
def test_dist_threshold_invalid_parameters():
|
||||
X = [[0], [1]]
|
||||
with pytest.raises(ValueError, match="Exactly one of "):
|
||||
AgglomerativeClustering(n_clusters=None, distance_threshold=None).fit(X)
|
||||
|
||||
with pytest.raises(ValueError, match="Exactly one of "):
|
||||
AgglomerativeClustering(n_clusters=2, distance_threshold=1).fit(X)
|
||||
|
||||
X = [[0], [1]]
|
||||
with pytest.raises(ValueError, match="compute_full_tree must be True if"):
|
||||
AgglomerativeClustering(
|
||||
n_clusters=None, distance_threshold=1, compute_full_tree=False
|
||||
).fit(X)
|
||||
|
||||
|
||||
def test_invalid_shape_precomputed_dist_matrix():
|
||||
# Check that an error is raised when affinity='precomputed'
|
||||
# and a non square matrix is passed (PR #16257).
|
||||
rng = np.random.RandomState(0)
|
||||
X = rng.rand(5, 3)
|
||||
with pytest.raises(
|
||||
ValueError,
|
||||
match=r"Distance matrix should be square, got matrix of shape \(5, 3\)",
|
||||
):
|
||||
AgglomerativeClustering(affinity="precomputed", linkage="complete").fit(X)
|
||||
|
||||
|
||||
def test_precomputed_connectivity_affinity_with_2_connected_components():
|
||||
"""Check that connecting components works when connectivity and
|
||||
affinity are both precomputed and the number of connected components is
|
||||
greater than 1. Non-regression test for #16151.
|
||||
"""
|
||||
|
||||
connectivity_matrix = np.array(
|
||||
[
|
||||
[0, 1, 1, 0, 0],
|
||||
[0, 0, 1, 0, 0],
|
||||
[0, 0, 0, 0, 0],
|
||||
[0, 0, 0, 0, 1],
|
||||
[0, 0, 0, 0, 0],
|
||||
]
|
||||
)
|
||||
# ensure that connectivity_matrix has two connected components
|
||||
assert connected_components(connectivity_matrix)[0] == 2
|
||||
|
||||
rng = np.random.RandomState(0)
|
||||
X = rng.randn(5, 10)
|
||||
|
||||
X_dist = pairwise_distances(X)
|
||||
clusterer_precomputed = AgglomerativeClustering(
|
||||
affinity="precomputed", connectivity=connectivity_matrix, linkage="complete"
|
||||
)
|
||||
msg = "Completing it to avoid stopping the tree early"
|
||||
with pytest.warns(UserWarning, match=msg):
|
||||
clusterer_precomputed.fit(X_dist)
|
||||
|
||||
clusterer = AgglomerativeClustering(
|
||||
connectivity=connectivity_matrix, linkage="complete"
|
||||
)
|
||||
with pytest.warns(UserWarning, match=msg):
|
||||
clusterer.fit(X)
|
||||
|
||||
assert_array_equal(clusterer.labels_, clusterer_precomputed.labels_)
|
||||
assert_array_equal(clusterer.children_, clusterer_precomputed.children_)
|
||||
File diff suppressed because it is too large
Load Diff
@@ -0,0 +1,213 @@
|
||||
"""
|
||||
Testing for mean shift clustering methods
|
||||
|
||||
"""
|
||||
|
||||
import numpy as np
|
||||
import warnings
|
||||
import pytest
|
||||
|
||||
from scipy import sparse
|
||||
|
||||
from sklearn.utils._testing import assert_array_equal
|
||||
from sklearn.utils._testing import assert_array_almost_equal
|
||||
from sklearn.utils._testing import assert_allclose
|
||||
|
||||
from sklearn.cluster import MeanShift
|
||||
from sklearn.cluster import mean_shift
|
||||
from sklearn.cluster import estimate_bandwidth
|
||||
from sklearn.cluster import get_bin_seeds
|
||||
from sklearn.datasets import make_blobs
|
||||
from sklearn.metrics import v_measure_score
|
||||
|
||||
|
||||
n_clusters = 3
|
||||
centers = np.array([[1, 1], [-1, -1], [1, -1]]) + 10
|
||||
X, _ = make_blobs(
|
||||
n_samples=300,
|
||||
n_features=2,
|
||||
centers=centers,
|
||||
cluster_std=0.4,
|
||||
shuffle=True,
|
||||
random_state=11,
|
||||
)
|
||||
|
||||
|
||||
def test_estimate_bandwidth():
|
||||
# Test estimate_bandwidth
|
||||
bandwidth = estimate_bandwidth(X, n_samples=200)
|
||||
assert 0.9 <= bandwidth <= 1.5
|
||||
|
||||
|
||||
def test_estimate_bandwidth_1sample():
|
||||
# Test estimate_bandwidth when n_samples=1 and quantile<1, so that
|
||||
# n_neighbors is set to 1.
|
||||
bandwidth = estimate_bandwidth(X, n_samples=1, quantile=0.3)
|
||||
assert bandwidth == pytest.approx(0.0, abs=1e-5)
|
||||
|
||||
|
||||
@pytest.mark.parametrize(
|
||||
"bandwidth, cluster_all, expected, first_cluster_label",
|
||||
[(1.2, True, 3, 0), (1.2, False, 4, -1)],
|
||||
)
|
||||
def test_mean_shift(bandwidth, cluster_all, expected, first_cluster_label):
|
||||
# Test MeanShift algorithm
|
||||
ms = MeanShift(bandwidth=bandwidth, cluster_all=cluster_all)
|
||||
labels = ms.fit(X).labels_
|
||||
labels_unique = np.unique(labels)
|
||||
n_clusters_ = len(labels_unique)
|
||||
assert n_clusters_ == expected
|
||||
assert labels_unique[0] == first_cluster_label
|
||||
|
||||
cluster_centers, labels_mean_shift = mean_shift(X, cluster_all=cluster_all)
|
||||
labels_mean_shift_unique = np.unique(labels_mean_shift)
|
||||
n_clusters_mean_shift = len(labels_mean_shift_unique)
|
||||
assert n_clusters_mean_shift == expected
|
||||
assert labels_mean_shift_unique[0] == first_cluster_label
|
||||
|
||||
|
||||
def test_mean_shift_negative_bandwidth():
|
||||
bandwidth = -1
|
||||
ms = MeanShift(bandwidth=bandwidth)
|
||||
msg = r"bandwidth needs to be greater than zero or None," r" got -1\.000000"
|
||||
with pytest.raises(ValueError, match=msg):
|
||||
ms.fit(X)
|
||||
|
||||
|
||||
def test_estimate_bandwidth_with_sparse_matrix():
|
||||
# Test estimate_bandwidth with sparse matrix
|
||||
X = sparse.lil_matrix((1000, 1000))
|
||||
msg = "A sparse matrix was passed, but dense data is required."
|
||||
with pytest.raises(TypeError, match=msg):
|
||||
estimate_bandwidth(X)
|
||||
|
||||
|
||||
def test_parallel():
|
||||
centers = np.array([[1, 1], [-1, -1], [1, -1]]) + 10
|
||||
X, _ = make_blobs(
|
||||
n_samples=50,
|
||||
n_features=2,
|
||||
centers=centers,
|
||||
cluster_std=0.4,
|
||||
shuffle=True,
|
||||
random_state=11,
|
||||
)
|
||||
|
||||
ms1 = MeanShift(n_jobs=2)
|
||||
ms1.fit(X)
|
||||
|
||||
ms2 = MeanShift()
|
||||
ms2.fit(X)
|
||||
|
||||
assert_array_almost_equal(ms1.cluster_centers_, ms2.cluster_centers_)
|
||||
assert_array_equal(ms1.labels_, ms2.labels_)
|
||||
|
||||
|
||||
def test_meanshift_predict():
|
||||
# Test MeanShift.predict
|
||||
ms = MeanShift(bandwidth=1.2)
|
||||
labels = ms.fit_predict(X)
|
||||
labels2 = ms.predict(X)
|
||||
assert_array_equal(labels, labels2)
|
||||
|
||||
|
||||
def test_meanshift_all_orphans():
|
||||
# init away from the data, crash with a sensible warning
|
||||
ms = MeanShift(bandwidth=0.1, seeds=[[-9, -9], [-10, -10]])
|
||||
msg = "No point was within bandwidth=0.1"
|
||||
with pytest.raises(ValueError, match=msg):
|
||||
ms.fit(
|
||||
X,
|
||||
)
|
||||
|
||||
|
||||
def test_unfitted():
|
||||
# Non-regression: before fit, there should be not fitted attributes.
|
||||
ms = MeanShift()
|
||||
assert not hasattr(ms, "cluster_centers_")
|
||||
assert not hasattr(ms, "labels_")
|
||||
|
||||
|
||||
def test_cluster_intensity_tie():
|
||||
X = np.array([[1, 1], [2, 1], [1, 0], [4, 7], [3, 5], [3, 6]])
|
||||
c1 = MeanShift(bandwidth=2).fit(X)
|
||||
|
||||
X = np.array([[4, 7], [3, 5], [3, 6], [1, 1], [2, 1], [1, 0]])
|
||||
c2 = MeanShift(bandwidth=2).fit(X)
|
||||
assert_array_equal(c1.labels_, [1, 1, 1, 0, 0, 0])
|
||||
assert_array_equal(c2.labels_, [0, 0, 0, 1, 1, 1])
|
||||
|
||||
|
||||
def test_bin_seeds():
|
||||
# Test the bin seeding technique which can be used in the mean shift
|
||||
# algorithm
|
||||
# Data is just 6 points in the plane
|
||||
X = np.array(
|
||||
[[1.0, 1.0], [1.4, 1.4], [1.8, 1.2], [2.0, 1.0], [2.1, 1.1], [0.0, 0.0]]
|
||||
)
|
||||
|
||||
# With a bin coarseness of 1.0 and min_bin_freq of 1, 3 bins should be
|
||||
# found
|
||||
ground_truth = {(1.0, 1.0), (2.0, 1.0), (0.0, 0.0)}
|
||||
test_bins = get_bin_seeds(X, 1, 1)
|
||||
test_result = set(tuple(p) for p in test_bins)
|
||||
assert len(ground_truth.symmetric_difference(test_result)) == 0
|
||||
|
||||
# With a bin coarseness of 1.0 and min_bin_freq of 2, 2 bins should be
|
||||
# found
|
||||
ground_truth = {(1.0, 1.0), (2.0, 1.0)}
|
||||
test_bins = get_bin_seeds(X, 1, 2)
|
||||
test_result = set(tuple(p) for p in test_bins)
|
||||
assert len(ground_truth.symmetric_difference(test_result)) == 0
|
||||
|
||||
# With a bin size of 0.01 and min_bin_freq of 1, 6 bins should be found
|
||||
# we bail and use the whole data here.
|
||||
with warnings.catch_warnings(record=True):
|
||||
test_bins = get_bin_seeds(X, 0.01, 1)
|
||||
assert_array_almost_equal(test_bins, X)
|
||||
|
||||
# tight clusters around [0, 0] and [1, 1], only get two bins
|
||||
X, _ = make_blobs(
|
||||
n_samples=100,
|
||||
n_features=2,
|
||||
centers=[[0, 0], [1, 1]],
|
||||
cluster_std=0.1,
|
||||
random_state=0,
|
||||
)
|
||||
test_bins = get_bin_seeds(X, 1)
|
||||
assert_array_equal(test_bins, [[0, 0], [1, 1]])
|
||||
|
||||
|
||||
@pytest.mark.parametrize("max_iter", [1, 100])
|
||||
def test_max_iter(max_iter):
|
||||
clusters1, _ = mean_shift(X, max_iter=max_iter)
|
||||
ms = MeanShift(max_iter=max_iter).fit(X)
|
||||
clusters2 = ms.cluster_centers_
|
||||
|
||||
assert ms.n_iter_ <= ms.max_iter
|
||||
assert len(clusters1) == len(clusters2)
|
||||
|
||||
for c1, c2 in zip(clusters1, clusters2):
|
||||
assert np.allclose(c1, c2)
|
||||
|
||||
|
||||
def test_mean_shift_zero_bandwidth():
|
||||
# Check that mean shift works when the estimated bandwidth is 0.
|
||||
X = np.array([1, 1, 1, 2, 2, 2, 3, 3]).reshape(-1, 1)
|
||||
|
||||
# estimate_bandwidth with default args returns 0 on this dataset
|
||||
bandwidth = estimate_bandwidth(X)
|
||||
assert bandwidth == 0
|
||||
|
||||
# get_bin_seeds with a 0 bin_size should return the dataset itself
|
||||
assert get_bin_seeds(X, bin_size=bandwidth) is X
|
||||
|
||||
# MeanShift with binning and a 0 estimated bandwidth should be equivalent
|
||||
# to no binning.
|
||||
ms_binning = MeanShift(bin_seeding=True, bandwidth=None).fit(X)
|
||||
ms_nobinning = MeanShift(bin_seeding=False).fit(X)
|
||||
expected_labels = np.array([0, 0, 0, 1, 1, 1, 2, 2])
|
||||
|
||||
assert v_measure_score(ms_binning.labels_, expected_labels) == 1
|
||||
assert v_measure_score(ms_nobinning.labels_, expected_labels) == 1
|
||||
assert_allclose(ms_binning.cluster_centers_, ms_nobinning.cluster_centers_)
|
||||
@@ -0,0 +1,806 @@
|
||||
# Authors: Shane Grigsby <refuge@rocktalus.com>
|
||||
# Adrin Jalali <adrin.jalali@gmail.com>
|
||||
# License: BSD 3 clause
|
||||
import numpy as np
|
||||
import pytest
|
||||
import warnings
|
||||
|
||||
from sklearn.datasets import make_blobs
|
||||
from sklearn.cluster import OPTICS
|
||||
from sklearn.cluster._optics import _extend_region, _extract_xi_labels
|
||||
from sklearn.exceptions import DataConversionWarning
|
||||
from sklearn.metrics.cluster import contingency_matrix
|
||||
from sklearn.metrics.pairwise import pairwise_distances
|
||||
from sklearn.cluster import DBSCAN
|
||||
from sklearn.utils import shuffle
|
||||
from sklearn.utils._testing import assert_array_equal
|
||||
from sklearn.utils._testing import assert_allclose
|
||||
|
||||
from sklearn.cluster.tests.common import generate_clustered_data
|
||||
|
||||
|
||||
rng = np.random.RandomState(0)
|
||||
n_points_per_cluster = 10
|
||||
C1 = [-5, -2] + 0.8 * rng.randn(n_points_per_cluster, 2)
|
||||
C2 = [4, -1] + 0.1 * rng.randn(n_points_per_cluster, 2)
|
||||
C3 = [1, -2] + 0.2 * rng.randn(n_points_per_cluster, 2)
|
||||
C4 = [-2, 3] + 0.3 * rng.randn(n_points_per_cluster, 2)
|
||||
C5 = [3, -2] + 1.6 * rng.randn(n_points_per_cluster, 2)
|
||||
C6 = [5, 6] + 2 * rng.randn(n_points_per_cluster, 2)
|
||||
X = np.vstack((C1, C2, C3, C4, C5, C6))
|
||||
|
||||
|
||||
@pytest.mark.parametrize(
|
||||
("r_plot", "end"),
|
||||
[
|
||||
[[10, 8.9, 8.8, 8.7, 7, 10], 3],
|
||||
[[10, 8.9, 8.8, 8.7, 8.6, 7, 10], 0],
|
||||
[[10, 8.9, 8.8, 8.7, 7, 6, np.inf], 4],
|
||||
[[10, 8.9, 8.8, 8.7, 7, 6, np.inf], 4],
|
||||
],
|
||||
)
|
||||
def test_extend_downward(r_plot, end):
|
||||
r_plot = np.array(r_plot)
|
||||
ratio = r_plot[:-1] / r_plot[1:]
|
||||
steep_downward = ratio >= 1 / 0.9
|
||||
upward = ratio < 1
|
||||
|
||||
e = _extend_region(steep_downward, upward, 0, 2)
|
||||
assert e == end
|
||||
|
||||
|
||||
@pytest.mark.parametrize(
|
||||
("r_plot", "end"),
|
||||
[
|
||||
[[1, 2, 2.1, 2.2, 4, 8, 8, np.inf], 6],
|
||||
[[1, 2, 2.1, 2.2, 2.3, 4, 8, 8, np.inf], 0],
|
||||
[[1, 2, 2.1, 2, np.inf], 0],
|
||||
[[1, 2, 2.1, np.inf], 2],
|
||||
],
|
||||
)
|
||||
def test_extend_upward(r_plot, end):
|
||||
r_plot = np.array(r_plot)
|
||||
ratio = r_plot[:-1] / r_plot[1:]
|
||||
steep_upward = ratio <= 0.9
|
||||
downward = ratio > 1
|
||||
|
||||
e = _extend_region(steep_upward, downward, 0, 2)
|
||||
assert e == end
|
||||
|
||||
|
||||
@pytest.mark.parametrize(
|
||||
("ordering", "clusters", "expected"),
|
||||
[
|
||||
[[0, 1, 2, 3], [[0, 1], [2, 3]], [0, 0, 1, 1]],
|
||||
[[0, 1, 2, 3], [[0, 1], [3, 3]], [0, 0, -1, 1]],
|
||||
[[0, 1, 2, 3], [[0, 1], [3, 3], [0, 3]], [0, 0, -1, 1]],
|
||||
[[3, 1, 2, 0], [[0, 1], [3, 3], [0, 3]], [1, 0, -1, 0]],
|
||||
],
|
||||
)
|
||||
def test_the_extract_xi_labels(ordering, clusters, expected):
|
||||
labels = _extract_xi_labels(ordering, clusters)
|
||||
|
||||
assert_array_equal(labels, expected)
|
||||
|
||||
|
||||
def test_extract_xi(global_dtype):
|
||||
# small and easy test (no clusters around other clusters)
|
||||
# but with a clear noise data.
|
||||
rng = np.random.RandomState(0)
|
||||
n_points_per_cluster = 5
|
||||
|
||||
C1 = [-5, -2] + 0.8 * rng.randn(n_points_per_cluster, 2)
|
||||
C2 = [4, -1] + 0.1 * rng.randn(n_points_per_cluster, 2)
|
||||
C3 = [1, -2] + 0.2 * rng.randn(n_points_per_cluster, 2)
|
||||
C4 = [-2, 3] + 0.3 * rng.randn(n_points_per_cluster, 2)
|
||||
C5 = [3, -2] + 0.6 * rng.randn(n_points_per_cluster, 2)
|
||||
C6 = [5, 6] + 0.2 * rng.randn(n_points_per_cluster, 2)
|
||||
|
||||
X = np.vstack((C1, C2, C3, C4, C5, np.array([[100, 100]]), C6)).astype(
|
||||
global_dtype, copy=False
|
||||
)
|
||||
expected_labels = np.r_[[2] * 5, [0] * 5, [1] * 5, [3] * 5, [1] * 5, -1, [4] * 5]
|
||||
X, expected_labels = shuffle(X, expected_labels, random_state=rng)
|
||||
|
||||
clust = OPTICS(
|
||||
min_samples=3, min_cluster_size=2, max_eps=20, cluster_method="xi", xi=0.4
|
||||
).fit(X)
|
||||
assert_array_equal(clust.labels_, expected_labels)
|
||||
|
||||
# check float min_samples and min_cluster_size
|
||||
clust = OPTICS(
|
||||
min_samples=0.1, min_cluster_size=0.08, max_eps=20, cluster_method="xi", xi=0.4
|
||||
).fit(X)
|
||||
assert_array_equal(clust.labels_, expected_labels)
|
||||
|
||||
X = np.vstack((C1, C2, C3, C4, C5, np.array([[100, 100]] * 2), C6)).astype(
|
||||
global_dtype, copy=False
|
||||
)
|
||||
expected_labels = np.r_[
|
||||
[1] * 5, [3] * 5, [2] * 5, [0] * 5, [2] * 5, -1, -1, [4] * 5
|
||||
]
|
||||
X, expected_labels = shuffle(X, expected_labels, random_state=rng)
|
||||
|
||||
clust = OPTICS(
|
||||
min_samples=3, min_cluster_size=3, max_eps=20, cluster_method="xi", xi=0.3
|
||||
).fit(X)
|
||||
# this may fail if the predecessor correction is not at work!
|
||||
assert_array_equal(clust.labels_, expected_labels)
|
||||
|
||||
C1 = [[0, 0], [0, 0.1], [0, -0.1], [0.1, 0]]
|
||||
C2 = [[10, 10], [10, 9], [10, 11], [9, 10]]
|
||||
C3 = [[100, 100], [100, 90], [100, 110], [90, 100]]
|
||||
X = np.vstack((C1, C2, C3)).astype(global_dtype, copy=False)
|
||||
expected_labels = np.r_[[0] * 4, [1] * 4, [2] * 4]
|
||||
X, expected_labels = shuffle(X, expected_labels, random_state=rng)
|
||||
|
||||
clust = OPTICS(
|
||||
min_samples=2, min_cluster_size=2, max_eps=np.inf, cluster_method="xi", xi=0.04
|
||||
).fit(X)
|
||||
assert_array_equal(clust.labels_, expected_labels)
|
||||
|
||||
|
||||
def test_cluster_hierarchy_(global_dtype):
|
||||
rng = np.random.RandomState(0)
|
||||
n_points_per_cluster = 100
|
||||
C1 = [0, 0] + 2 * rng.randn(n_points_per_cluster, 2).astype(
|
||||
global_dtype, copy=False
|
||||
)
|
||||
C2 = [0, 0] + 50 * rng.randn(n_points_per_cluster, 2).astype(
|
||||
global_dtype, copy=False
|
||||
)
|
||||
X = np.vstack((C1, C2))
|
||||
X = shuffle(X, random_state=0)
|
||||
|
||||
clusters = OPTICS(min_samples=20, xi=0.1).fit(X).cluster_hierarchy_
|
||||
assert clusters.shape == (2, 2)
|
||||
diff = np.sum(clusters - np.array([[0, 99], [0, 199]]))
|
||||
assert diff / len(X) < 0.05
|
||||
|
||||
|
||||
def test_correct_number_of_clusters():
|
||||
# in 'auto' mode
|
||||
|
||||
n_clusters = 3
|
||||
X = generate_clustered_data(n_clusters=n_clusters)
|
||||
# Parameters chosen specifically for this task.
|
||||
# Compute OPTICS
|
||||
clust = OPTICS(max_eps=5.0 * 6.0, min_samples=4, xi=0.1)
|
||||
clust.fit(X)
|
||||
# number of clusters, ignoring noise if present
|
||||
n_clusters_1 = len(set(clust.labels_)) - int(-1 in clust.labels_)
|
||||
assert n_clusters_1 == n_clusters
|
||||
|
||||
# check attribute types and sizes
|
||||
assert clust.labels_.shape == (len(X),)
|
||||
assert clust.labels_.dtype.kind == "i"
|
||||
|
||||
assert clust.reachability_.shape == (len(X),)
|
||||
assert clust.reachability_.dtype.kind == "f"
|
||||
|
||||
assert clust.core_distances_.shape == (len(X),)
|
||||
assert clust.core_distances_.dtype.kind == "f"
|
||||
|
||||
assert clust.ordering_.shape == (len(X),)
|
||||
assert clust.ordering_.dtype.kind == "i"
|
||||
assert set(clust.ordering_) == set(range(len(X)))
|
||||
|
||||
|
||||
def test_minimum_number_of_sample_check():
|
||||
# test that we check a minimum number of samples
|
||||
msg = "min_samples must be no greater than"
|
||||
|
||||
# Compute OPTICS
|
||||
X = [[1, 1]]
|
||||
clust = OPTICS(max_eps=5.0 * 0.3, min_samples=10, min_cluster_size=1)
|
||||
|
||||
# Run the fit
|
||||
with pytest.raises(ValueError, match=msg):
|
||||
clust.fit(X)
|
||||
|
||||
|
||||
def test_bad_extract():
|
||||
# Test an extraction of eps too close to original eps
|
||||
msg = "Specify an epsilon smaller than 0.15. Got 0.3."
|
||||
centers = [[1, 1], [-1, -1], [1, -1]]
|
||||
X, labels_true = make_blobs(
|
||||
n_samples=750, centers=centers, cluster_std=0.4, random_state=0
|
||||
)
|
||||
|
||||
# Compute OPTICS
|
||||
clust = OPTICS(max_eps=5.0 * 0.03, cluster_method="dbscan", eps=0.3, min_samples=10)
|
||||
with pytest.raises(ValueError, match=msg):
|
||||
clust.fit(X)
|
||||
|
||||
|
||||
def test_bad_reachability():
|
||||
msg = "All reachability values are inf. Set a larger max_eps."
|
||||
centers = [[1, 1], [-1, -1], [1, -1]]
|
||||
X, labels_true = make_blobs(
|
||||
n_samples=750, centers=centers, cluster_std=0.4, random_state=0
|
||||
)
|
||||
|
||||
with pytest.warns(UserWarning, match=msg):
|
||||
clust = OPTICS(max_eps=5.0 * 0.003, min_samples=10, eps=0.015)
|
||||
clust.fit(X)
|
||||
|
||||
|
||||
def test_nowarn_if_metric_bool_data_bool():
|
||||
# make sure no warning is raised if metric and data are both boolean
|
||||
# non-regression test for
|
||||
# https://github.com/scikit-learn/scikit-learn/issues/18996
|
||||
|
||||
pairwise_metric = "rogerstanimoto"
|
||||
X = np.random.randint(2, size=(5, 2), dtype=bool)
|
||||
|
||||
with warnings.catch_warnings():
|
||||
warnings.simplefilter("error", DataConversionWarning)
|
||||
|
||||
OPTICS(metric=pairwise_metric).fit(X)
|
||||
|
||||
|
||||
def test_warn_if_metric_bool_data_no_bool():
|
||||
# make sure a *single* conversion warning is raised if metric is boolean
|
||||
# but data isn't
|
||||
# non-regression test for
|
||||
# https://github.com/scikit-learn/scikit-learn/issues/18996
|
||||
|
||||
pairwise_metric = "rogerstanimoto"
|
||||
X = np.random.randint(2, size=(5, 2), dtype=np.int32)
|
||||
msg = f"Data will be converted to boolean for metric {pairwise_metric}"
|
||||
|
||||
with pytest.warns(DataConversionWarning, match=msg) as warn_record:
|
||||
OPTICS(metric=pairwise_metric).fit(X)
|
||||
assert len(warn_record) == 1
|
||||
|
||||
|
||||
def test_nowarn_if_metric_no_bool():
|
||||
# make sure no conversion warning is raised if
|
||||
# metric isn't boolean, no matter what the data type is
|
||||
pairwise_metric = "minkowski"
|
||||
X_bool = np.random.randint(2, size=(5, 2), dtype=bool)
|
||||
X_num = np.random.randint(2, size=(5, 2), dtype=np.int32)
|
||||
|
||||
with warnings.catch_warnings():
|
||||
warnings.simplefilter("error", DataConversionWarning)
|
||||
|
||||
# fit boolean data
|
||||
OPTICS(metric=pairwise_metric).fit(X_bool)
|
||||
# fit numeric data
|
||||
OPTICS(metric=pairwise_metric).fit(X_num)
|
||||
|
||||
|
||||
def test_close_extract():
|
||||
# Test extract where extraction eps is close to scaled max_eps
|
||||
|
||||
centers = [[1, 1], [-1, -1], [1, -1]]
|
||||
X, labels_true = make_blobs(
|
||||
n_samples=750, centers=centers, cluster_std=0.4, random_state=0
|
||||
)
|
||||
|
||||
# Compute OPTICS
|
||||
clust = OPTICS(max_eps=1.0, cluster_method="dbscan", eps=0.3, min_samples=10).fit(X)
|
||||
# Cluster ordering starts at 0; max cluster label = 2 is 3 clusters
|
||||
assert max(clust.labels_) == 2
|
||||
|
||||
|
||||
@pytest.mark.parametrize("eps", [0.1, 0.3, 0.5])
|
||||
@pytest.mark.parametrize("min_samples", [3, 10, 20])
|
||||
def test_dbscan_optics_parity(eps, min_samples, global_dtype):
|
||||
# Test that OPTICS clustering labels are <= 5% difference of DBSCAN
|
||||
|
||||
centers = [[1, 1], [-1, -1], [1, -1]]
|
||||
X, labels_true = make_blobs(
|
||||
n_samples=750, centers=centers, cluster_std=0.4, random_state=0
|
||||
)
|
||||
|
||||
X = X.astype(global_dtype, copy=False)
|
||||
|
||||
# calculate optics with dbscan extract at 0.3 epsilon
|
||||
op = OPTICS(min_samples=min_samples, cluster_method="dbscan", eps=eps).fit(X)
|
||||
|
||||
# calculate dbscan labels
|
||||
db = DBSCAN(eps=eps, min_samples=min_samples).fit(X)
|
||||
|
||||
contingency = contingency_matrix(db.labels_, op.labels_)
|
||||
agree = min(
|
||||
np.sum(np.max(contingency, axis=0)), np.sum(np.max(contingency, axis=1))
|
||||
)
|
||||
disagree = X.shape[0] - agree
|
||||
|
||||
percent_mismatch = np.round((disagree - 1) / X.shape[0], 2)
|
||||
|
||||
# verify label mismatch is <= 5% labels
|
||||
assert percent_mismatch <= 0.05
|
||||
|
||||
|
||||
def test_min_samples_edge_case(global_dtype):
|
||||
C1 = [[0, 0], [0, 0.1], [0, -0.1]]
|
||||
C2 = [[10, 10], [10, 9], [10, 11]]
|
||||
C3 = [[100, 100], [100, 96], [100, 106]]
|
||||
X = np.vstack((C1, C2, C3)).astype(global_dtype, copy=False)
|
||||
|
||||
expected_labels = np.r_[[0] * 3, [1] * 3, [2] * 3]
|
||||
clust = OPTICS(min_samples=3, max_eps=7, cluster_method="xi", xi=0.04).fit(X)
|
||||
assert_array_equal(clust.labels_, expected_labels)
|
||||
|
||||
expected_labels = np.r_[[0] * 3, [1] * 3, [-1] * 3]
|
||||
clust = OPTICS(min_samples=3, max_eps=3, cluster_method="xi", xi=0.04).fit(X)
|
||||
assert_array_equal(clust.labels_, expected_labels)
|
||||
|
||||
expected_labels = np.r_[[-1] * 9]
|
||||
with pytest.warns(UserWarning, match="All reachability values"):
|
||||
clust = OPTICS(min_samples=4, max_eps=3, cluster_method="xi", xi=0.04).fit(X)
|
||||
assert_array_equal(clust.labels_, expected_labels)
|
||||
|
||||
|
||||
# try arbitrary minimum sizes
|
||||
@pytest.mark.parametrize("min_cluster_size", range(2, X.shape[0] // 10, 23))
|
||||
def test_min_cluster_size(min_cluster_size, global_dtype):
|
||||
redX = X[::2].astype(global_dtype, copy=False) # reduce for speed
|
||||
clust = OPTICS(min_samples=9, min_cluster_size=min_cluster_size).fit(redX)
|
||||
cluster_sizes = np.bincount(clust.labels_[clust.labels_ != -1])
|
||||
if cluster_sizes.size:
|
||||
assert min(cluster_sizes) >= min_cluster_size
|
||||
# check behaviour is the same when min_cluster_size is a fraction
|
||||
clust_frac = OPTICS(
|
||||
min_samples=9, min_cluster_size=min_cluster_size / redX.shape[0]
|
||||
)
|
||||
clust_frac.fit(redX)
|
||||
assert_array_equal(clust.labels_, clust_frac.labels_)
|
||||
|
||||
|
||||
@pytest.mark.parametrize("min_cluster_size", [0, -1, 1.1, 2.2])
|
||||
def test_min_cluster_size_invalid(min_cluster_size):
|
||||
clust = OPTICS(min_cluster_size=min_cluster_size)
|
||||
with pytest.raises(ValueError, match="must be a positive integer or a "):
|
||||
clust.fit(X)
|
||||
|
||||
|
||||
def test_min_cluster_size_invalid2():
|
||||
clust = OPTICS(min_cluster_size=len(X) + 1)
|
||||
with pytest.raises(ValueError, match="must be no greater than the "):
|
||||
clust.fit(X)
|
||||
|
||||
|
||||
def test_processing_order():
|
||||
# Ensure that we consider all unprocessed points,
|
||||
# not only direct neighbors. when picking the next point.
|
||||
Y = [[0], [10], [-10], [25]]
|
||||
clust = OPTICS(min_samples=3, max_eps=15).fit(Y)
|
||||
assert_array_equal(clust.reachability_, [np.inf, 10, 10, 15])
|
||||
assert_array_equal(clust.core_distances_, [10, 15, np.inf, np.inf])
|
||||
assert_array_equal(clust.ordering_, [0, 1, 2, 3])
|
||||
|
||||
|
||||
def test_compare_to_ELKI():
|
||||
# Expected values, computed with (future) ELKI 0.7.5 using:
|
||||
# java -jar elki.jar cli -dbc.in csv -dbc.filter FixedDBIDsFilter
|
||||
# -algorithm clustering.optics.OPTICSHeap -optics.minpts 5
|
||||
# where the FixedDBIDsFilter gives 0-indexed ids.
|
||||
r1 = [
|
||||
np.inf,
|
||||
1.0574896366427478,
|
||||
0.7587934993548423,
|
||||
0.7290174038973836,
|
||||
0.7290174038973836,
|
||||
0.7290174038973836,
|
||||
0.6861627576116127,
|
||||
0.7587934993548423,
|
||||
0.9280118450166668,
|
||||
1.1748022534146194,
|
||||
3.3355455741292257,
|
||||
0.49618389254482587,
|
||||
0.2552805046961355,
|
||||
0.2552805046961355,
|
||||
0.24944622248445714,
|
||||
0.24944622248445714,
|
||||
0.24944622248445714,
|
||||
0.2552805046961355,
|
||||
0.2552805046961355,
|
||||
0.3086779122185853,
|
||||
4.163024452756142,
|
||||
1.623152630340929,
|
||||
0.45315840475822655,
|
||||
0.25468325192031926,
|
||||
0.2254004358159971,
|
||||
0.18765711877083036,
|
||||
0.1821471333893275,
|
||||
0.1821471333893275,
|
||||
0.18765711877083036,
|
||||
0.18765711877083036,
|
||||
0.2240202988740153,
|
||||
1.154337614548715,
|
||||
1.342604473837069,
|
||||
1.323308536402633,
|
||||
0.8607514948648837,
|
||||
0.27219111215810565,
|
||||
0.13260875220533205,
|
||||
0.13260875220533205,
|
||||
0.09890587675958984,
|
||||
0.09890587675958984,
|
||||
0.13548790801634494,
|
||||
0.1575483940837384,
|
||||
0.17515137170530226,
|
||||
0.17575920159442388,
|
||||
0.27219111215810565,
|
||||
0.6101447895405373,
|
||||
1.3189208094864302,
|
||||
1.323308536402633,
|
||||
2.2509184159764577,
|
||||
2.4517810628594527,
|
||||
3.675977064404973,
|
||||
3.8264795626020365,
|
||||
2.9130735341510614,
|
||||
2.9130735341510614,
|
||||
2.9130735341510614,
|
||||
2.9130735341510614,
|
||||
2.8459300127258036,
|
||||
2.8459300127258036,
|
||||
2.8459300127258036,
|
||||
3.0321982337972537,
|
||||
]
|
||||
o1 = [
|
||||
0,
|
||||
3,
|
||||
6,
|
||||
4,
|
||||
7,
|
||||
8,
|
||||
2,
|
||||
9,
|
||||
5,
|
||||
1,
|
||||
31,
|
||||
30,
|
||||
32,
|
||||
34,
|
||||
33,
|
||||
38,
|
||||
39,
|
||||
35,
|
||||
37,
|
||||
36,
|
||||
44,
|
||||
21,
|
||||
23,
|
||||
24,
|
||||
22,
|
||||
25,
|
||||
27,
|
||||
29,
|
||||
26,
|
||||
28,
|
||||
20,
|
||||
40,
|
||||
45,
|
||||
46,
|
||||
10,
|
||||
15,
|
||||
11,
|
||||
13,
|
||||
17,
|
||||
19,
|
||||
18,
|
||||
12,
|
||||
16,
|
||||
14,
|
||||
47,
|
||||
49,
|
||||
43,
|
||||
48,
|
||||
42,
|
||||
41,
|
||||
53,
|
||||
57,
|
||||
51,
|
||||
52,
|
||||
56,
|
||||
59,
|
||||
54,
|
||||
55,
|
||||
58,
|
||||
50,
|
||||
]
|
||||
p1 = [
|
||||
-1,
|
||||
0,
|
||||
3,
|
||||
6,
|
||||
6,
|
||||
6,
|
||||
8,
|
||||
3,
|
||||
7,
|
||||
5,
|
||||
1,
|
||||
31,
|
||||
30,
|
||||
30,
|
||||
34,
|
||||
34,
|
||||
34,
|
||||
32,
|
||||
32,
|
||||
37,
|
||||
36,
|
||||
44,
|
||||
21,
|
||||
23,
|
||||
24,
|
||||
22,
|
||||
25,
|
||||
25,
|
||||
22,
|
||||
22,
|
||||
22,
|
||||
21,
|
||||
40,
|
||||
45,
|
||||
46,
|
||||
10,
|
||||
15,
|
||||
15,
|
||||
13,
|
||||
13,
|
||||
15,
|
||||
11,
|
||||
19,
|
||||
15,
|
||||
10,
|
||||
47,
|
||||
12,
|
||||
45,
|
||||
14,
|
||||
43,
|
||||
42,
|
||||
53,
|
||||
57,
|
||||
57,
|
||||
57,
|
||||
57,
|
||||
59,
|
||||
59,
|
||||
59,
|
||||
58,
|
||||
]
|
||||
|
||||
# Tests against known extraction array
|
||||
# Does NOT work with metric='euclidean', because sklearn euclidean has
|
||||
# worse numeric precision. 'minkowski' is slower but more accurate.
|
||||
clust1 = OPTICS(min_samples=5).fit(X)
|
||||
|
||||
assert_array_equal(clust1.ordering_, np.array(o1))
|
||||
assert_array_equal(clust1.predecessor_[clust1.ordering_], np.array(p1))
|
||||
assert_allclose(clust1.reachability_[clust1.ordering_], np.array(r1))
|
||||
# ELKI currently does not print the core distances (which are not used much
|
||||
# in literature, but we can at least ensure to have this consistency:
|
||||
for i in clust1.ordering_[1:]:
|
||||
assert clust1.reachability_[i] >= clust1.core_distances_[clust1.predecessor_[i]]
|
||||
|
||||
# Expected values, computed with (future) ELKI 0.7.5 using
|
||||
r2 = [
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
0.27219111215810565,
|
||||
0.13260875220533205,
|
||||
0.13260875220533205,
|
||||
0.09890587675958984,
|
||||
0.09890587675958984,
|
||||
0.13548790801634494,
|
||||
0.1575483940837384,
|
||||
0.17515137170530226,
|
||||
0.17575920159442388,
|
||||
0.27219111215810565,
|
||||
0.4928068613197889,
|
||||
np.inf,
|
||||
0.2666183922512113,
|
||||
0.18765711877083036,
|
||||
0.1821471333893275,
|
||||
0.1821471333893275,
|
||||
0.1821471333893275,
|
||||
0.18715928772277457,
|
||||
0.18765711877083036,
|
||||
0.18765711877083036,
|
||||
0.25468325192031926,
|
||||
np.inf,
|
||||
0.2552805046961355,
|
||||
0.2552805046961355,
|
||||
0.24944622248445714,
|
||||
0.24944622248445714,
|
||||
0.24944622248445714,
|
||||
0.2552805046961355,
|
||||
0.2552805046961355,
|
||||
0.3086779122185853,
|
||||
0.34466409325984865,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
np.inf,
|
||||
]
|
||||
o2 = [
|
||||
0,
|
||||
1,
|
||||
2,
|
||||
3,
|
||||
4,
|
||||
5,
|
||||
6,
|
||||
7,
|
||||
8,
|
||||
9,
|
||||
10,
|
||||
15,
|
||||
11,
|
||||
13,
|
||||
17,
|
||||
19,
|
||||
18,
|
||||
12,
|
||||
16,
|
||||
14,
|
||||
47,
|
||||
46,
|
||||
20,
|
||||
22,
|
||||
25,
|
||||
23,
|
||||
27,
|
||||
29,
|
||||
24,
|
||||
26,
|
||||
28,
|
||||
21,
|
||||
30,
|
||||
32,
|
||||
34,
|
||||
33,
|
||||
38,
|
||||
39,
|
||||
35,
|
||||
37,
|
||||
36,
|
||||
31,
|
||||
40,
|
||||
41,
|
||||
42,
|
||||
43,
|
||||
44,
|
||||
45,
|
||||
48,
|
||||
49,
|
||||
50,
|
||||
51,
|
||||
52,
|
||||
53,
|
||||
54,
|
||||
55,
|
||||
56,
|
||||
57,
|
||||
58,
|
||||
59,
|
||||
]
|
||||
p2 = [
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
10,
|
||||
15,
|
||||
15,
|
||||
13,
|
||||
13,
|
||||
15,
|
||||
11,
|
||||
19,
|
||||
15,
|
||||
10,
|
||||
47,
|
||||
-1,
|
||||
20,
|
||||
22,
|
||||
25,
|
||||
25,
|
||||
25,
|
||||
25,
|
||||
22,
|
||||
22,
|
||||
23,
|
||||
-1,
|
||||
30,
|
||||
30,
|
||||
34,
|
||||
34,
|
||||
34,
|
||||
32,
|
||||
32,
|
||||
37,
|
||||
38,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
-1,
|
||||
]
|
||||
clust2 = OPTICS(min_samples=5, max_eps=0.5).fit(X)
|
||||
|
||||
assert_array_equal(clust2.ordering_, np.array(o2))
|
||||
assert_array_equal(clust2.predecessor_[clust2.ordering_], np.array(p2))
|
||||
assert_allclose(clust2.reachability_[clust2.ordering_], np.array(r2))
|
||||
|
||||
index = np.where(clust1.core_distances_ <= 0.5)[0]
|
||||
assert_allclose(clust1.core_distances_[index], clust2.core_distances_[index])
|
||||
|
||||
|
||||
def test_wrong_cluster_method():
|
||||
clust = OPTICS(cluster_method="superfancy")
|
||||
with pytest.raises(ValueError, match="cluster_method should be one of "):
|
||||
clust.fit(X)
|
||||
|
||||
|
||||
def test_extract_dbscan(global_dtype):
|
||||
# testing an easy dbscan case. Not including clusters with different
|
||||
# densities.
|
||||
rng = np.random.RandomState(0)
|
||||
n_points_per_cluster = 20
|
||||
C1 = [-5, -2] + 0.2 * rng.randn(n_points_per_cluster, 2)
|
||||
C2 = [4, -1] + 0.2 * rng.randn(n_points_per_cluster, 2)
|
||||
C3 = [1, 2] + 0.2 * rng.randn(n_points_per_cluster, 2)
|
||||
C4 = [-2, 3] + 0.2 * rng.randn(n_points_per_cluster, 2)
|
||||
X = np.vstack((C1, C2, C3, C4)).astype(global_dtype, copy=False)
|
||||
|
||||
clust = OPTICS(cluster_method="dbscan", eps=0.5).fit(X)
|
||||
assert_array_equal(np.sort(np.unique(clust.labels_)), [0, 1, 2, 3])
|
||||
|
||||
|
||||
def test_precomputed_dists(global_dtype):
|
||||
redX = X[::2].astype(global_dtype, copy=False)
|
||||
dists = pairwise_distances(redX, metric="euclidean")
|
||||
clust1 = OPTICS(min_samples=10, algorithm="brute", metric="precomputed").fit(dists)
|
||||
clust2 = OPTICS(min_samples=10, algorithm="brute", metric="euclidean").fit(redX)
|
||||
|
||||
assert_allclose(clust1.reachability_, clust2.reachability_)
|
||||
assert_array_equal(clust1.labels_, clust2.labels_)
|
||||
@@ -0,0 +1,414 @@
|
||||
"""Testing for Spectral Clustering methods"""
|
||||
import re
|
||||
|
||||
import numpy as np
|
||||
from scipy import sparse
|
||||
from scipy.linalg import LinAlgError
|
||||
|
||||
import pytest
|
||||
|
||||
import pickle
|
||||
|
||||
from sklearn.utils import check_random_state
|
||||
from sklearn.utils._testing import assert_array_equal
|
||||
|
||||
from sklearn.cluster import SpectralClustering, spectral_clustering
|
||||
from sklearn.cluster._spectral import discretize, cluster_qr
|
||||
from sklearn.feature_extraction import img_to_graph
|
||||
from sklearn.metrics import pairwise_distances
|
||||
from sklearn.metrics import adjusted_rand_score
|
||||
from sklearn.metrics.pairwise import kernel_metrics, rbf_kernel
|
||||
from sklearn.neighbors import NearestNeighbors
|
||||
from sklearn.datasets import make_blobs
|
||||
|
||||
try:
|
||||
from pyamg import smoothed_aggregation_solver # noqa
|
||||
|
||||
amg_loaded = True
|
||||
except ImportError:
|
||||
amg_loaded = False
|
||||
|
||||
centers = np.array([[1, 1], [-1, -1], [1, -1]]) + 10
|
||||
X, _ = make_blobs(
|
||||
n_samples=60,
|
||||
n_features=2,
|
||||
centers=centers,
|
||||
cluster_std=0.4,
|
||||
shuffle=True,
|
||||
random_state=0,
|
||||
)
|
||||
|
||||
|
||||
@pytest.mark.parametrize("eigen_solver", ("arpack", "lobpcg"))
|
||||
@pytest.mark.parametrize("assign_labels", ("kmeans", "discretize", "cluster_qr"))
|
||||
def test_spectral_clustering(eigen_solver, assign_labels):
|
||||
S = np.array(
|
||||
[
|
||||
[1.0, 1.0, 1.0, 0.2, 0.0, 0.0, 0.0],
|
||||
[1.0, 1.0, 1.0, 0.2, 0.0, 0.0, 0.0],
|
||||
[1.0, 1.0, 1.0, 0.2, 0.0, 0.0, 0.0],
|
||||
[0.2, 0.2, 0.2, 1.0, 1.0, 1.0, 1.0],
|
||||
[0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0],
|
||||
[0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0],
|
||||
[0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0],
|
||||
]
|
||||
)
|
||||
|
||||
for mat in (S, sparse.csr_matrix(S)):
|
||||
model = SpectralClustering(
|
||||
random_state=0,
|
||||
n_clusters=2,
|
||||
affinity="precomputed",
|
||||
eigen_solver=eigen_solver,
|
||||
assign_labels=assign_labels,
|
||||
).fit(mat)
|
||||
labels = model.labels_
|
||||
if labels[0] == 0:
|
||||
labels = 1 - labels
|
||||
|
||||
assert adjusted_rand_score(labels, [1, 1, 1, 0, 0, 0, 0]) == 1
|
||||
|
||||
model_copy = pickle.loads(pickle.dumps(model))
|
||||
assert model_copy.n_clusters == model.n_clusters
|
||||
assert model_copy.eigen_solver == model.eigen_solver
|
||||
assert_array_equal(model_copy.labels_, model.labels_)
|
||||
|
||||
|
||||
def test_spectral_unknown_mode():
|
||||
# Test that SpectralClustering fails with an unknown mode set.
|
||||
centers = np.array(
|
||||
[
|
||||
[0.0, 0.0, 0.0],
|
||||
[10.0, 10.0, 10.0],
|
||||
[20.0, 20.0, 20.0],
|
||||
]
|
||||
)
|
||||
X, true_labels = make_blobs(
|
||||
n_samples=100, centers=centers, cluster_std=1.0, random_state=42
|
||||
)
|
||||
D = pairwise_distances(X) # Distance matrix
|
||||
S = np.max(D) - D # Similarity matrix
|
||||
S = sparse.coo_matrix(S)
|
||||
with pytest.raises(ValueError):
|
||||
spectral_clustering(S, n_clusters=2, random_state=0, eigen_solver="<unknown>")
|
||||
|
||||
|
||||
def test_spectral_unknown_assign_labels():
|
||||
# Test that SpectralClustering fails with an unknown assign_labels set.
|
||||
centers = np.array(
|
||||
[
|
||||
[0.0, 0.0, 0.0],
|
||||
[10.0, 10.0, 10.0],
|
||||
[20.0, 20.0, 20.0],
|
||||
]
|
||||
)
|
||||
X, true_labels = make_blobs(
|
||||
n_samples=100, centers=centers, cluster_std=1.0, random_state=42
|
||||
)
|
||||
D = pairwise_distances(X) # Distance matrix
|
||||
S = np.max(D) - D # Similarity matrix
|
||||
S = sparse.coo_matrix(S)
|
||||
with pytest.raises(ValueError):
|
||||
spectral_clustering(S, n_clusters=2, random_state=0, assign_labels="<unknown>")
|
||||
|
||||
|
||||
@pytest.mark.parametrize(
|
||||
"input, params, err_type, err_msg",
|
||||
[
|
||||
(X, {"n_clusters": -1}, ValueError, "n_clusters == -1, must be >= 1"),
|
||||
(X, {"n_clusters": 0}, ValueError, "n_clusters == 0, must be >= 1"),
|
||||
(
|
||||
X,
|
||||
{"n_clusters": 1.5},
|
||||
TypeError,
|
||||
"n_clusters must be an instance of int, not float",
|
||||
),
|
||||
(X, {"n_init": -1}, ValueError, "n_init == -1, must be >= 1"),
|
||||
(X, {"n_init": 0}, ValueError, "n_init == 0, must be >= 1"),
|
||||
(
|
||||
X,
|
||||
{"n_init": 1.5},
|
||||
TypeError,
|
||||
"n_init must be an instance of int, not float",
|
||||
),
|
||||
(X, {"gamma": -1}, ValueError, "gamma == -1, must be >= 1"),
|
||||
(X, {"gamma": 0}, ValueError, "gamma == 0, must be >= 1"),
|
||||
(X, {"n_neighbors": -1}, ValueError, "n_neighbors == -1, must be >= 1"),
|
||||
(X, {"n_neighbors": 0}, ValueError, "n_neighbors == 0, must be >= 1"),
|
||||
(
|
||||
X,
|
||||
{"eigen_tol": -1, "eigen_solver": "arpack"},
|
||||
ValueError,
|
||||
"eigen_tol == -1, must be >= 0",
|
||||
),
|
||||
(X, {"degree": -1}, ValueError, "degree == -1, must be >= 1"),
|
||||
(X, {"degree": 0}, ValueError, "degree == 0, must be >= 1"),
|
||||
],
|
||||
)
|
||||
def test_spectral_params_validation(input, params, err_type, err_msg):
|
||||
"""Check the parameters validation in `SpectralClustering`."""
|
||||
est = SpectralClustering(**params)
|
||||
with pytest.raises(err_type, match=err_msg):
|
||||
est.fit(input)
|
||||
|
||||
|
||||
@pytest.mark.parametrize("assign_labels", ("kmeans", "discretize", "cluster_qr"))
|
||||
def test_spectral_clustering_sparse(assign_labels):
|
||||
X, y = make_blobs(
|
||||
n_samples=20, random_state=0, centers=[[1, 1], [-1, -1]], cluster_std=0.01
|
||||
)
|
||||
|
||||
S = rbf_kernel(X, gamma=1)
|
||||
S = np.maximum(S - 1e-4, 0)
|
||||
S = sparse.coo_matrix(S)
|
||||
|
||||
labels = (
|
||||
SpectralClustering(
|
||||
random_state=0,
|
||||
n_clusters=2,
|
||||
affinity="precomputed",
|
||||
assign_labels=assign_labels,
|
||||
)
|
||||
.fit(S)
|
||||
.labels_
|
||||
)
|
||||
assert adjusted_rand_score(y, labels) == 1
|
||||
|
||||
|
||||
def test_precomputed_nearest_neighbors_filtering():
|
||||
# Test precomputed graph filtering when containing too many neighbors
|
||||
X, y = make_blobs(
|
||||
n_samples=200, random_state=0, centers=[[1, 1], [-1, -1]], cluster_std=0.01
|
||||
)
|
||||
|
||||
n_neighbors = 2
|
||||
results = []
|
||||
for additional_neighbors in [0, 10]:
|
||||
nn = NearestNeighbors(n_neighbors=n_neighbors + additional_neighbors).fit(X)
|
||||
graph = nn.kneighbors_graph(X, mode="connectivity")
|
||||
labels = (
|
||||
SpectralClustering(
|
||||
random_state=0,
|
||||
n_clusters=2,
|
||||
affinity="precomputed_nearest_neighbors",
|
||||
n_neighbors=n_neighbors,
|
||||
)
|
||||
.fit(graph)
|
||||
.labels_
|
||||
)
|
||||
results.append(labels)
|
||||
|
||||
assert_array_equal(results[0], results[1])
|
||||
|
||||
|
||||
def test_affinities():
|
||||
# Note: in the following, random_state has been selected to have
|
||||
# a dataset that yields a stable eigen decomposition both when built
|
||||
# on OSX and Linux
|
||||
X, y = make_blobs(
|
||||
n_samples=20, random_state=0, centers=[[1, 1], [-1, -1]], cluster_std=0.01
|
||||
)
|
||||
# nearest neighbors affinity
|
||||
sp = SpectralClustering(n_clusters=2, affinity="nearest_neighbors", random_state=0)
|
||||
with pytest.warns(UserWarning, match="not fully connected"):
|
||||
sp.fit(X)
|
||||
assert adjusted_rand_score(y, sp.labels_) == 1
|
||||
|
||||
sp = SpectralClustering(n_clusters=2, gamma=2, random_state=0)
|
||||
labels = sp.fit(X).labels_
|
||||
assert adjusted_rand_score(y, labels) == 1
|
||||
|
||||
X = check_random_state(10).rand(10, 5) * 10
|
||||
|
||||
kernels_available = kernel_metrics()
|
||||
for kern in kernels_available:
|
||||
# Additive chi^2 gives a negative similarity matrix which
|
||||
# doesn't make sense for spectral clustering
|
||||
if kern != "additive_chi2":
|
||||
sp = SpectralClustering(n_clusters=2, affinity=kern, random_state=0)
|
||||
labels = sp.fit(X).labels_
|
||||
assert (X.shape[0],) == labels.shape
|
||||
|
||||
sp = SpectralClustering(n_clusters=2, affinity=lambda x, y: 1, random_state=0)
|
||||
labels = sp.fit(X).labels_
|
||||
assert (X.shape[0],) == labels.shape
|
||||
|
||||
def histogram(x, y, **kwargs):
|
||||
# Histogram kernel implemented as a callable.
|
||||
assert kwargs == {} # no kernel_params that we didn't ask for
|
||||
return np.minimum(x, y).sum()
|
||||
|
||||
sp = SpectralClustering(n_clusters=2, affinity=histogram, random_state=0)
|
||||
labels = sp.fit(X).labels_
|
||||
assert (X.shape[0],) == labels.shape
|
||||
|
||||
# raise error on unknown affinity
|
||||
sp = SpectralClustering(n_clusters=2, affinity="<unknown>")
|
||||
with pytest.raises(ValueError):
|
||||
sp.fit(X)
|
||||
|
||||
|
||||
def test_cluster_qr():
|
||||
# cluster_qr by itself should not be used for clustering generic data
|
||||
# other than the rows of the eigenvectors within spectral clustering,
|
||||
# but cluster_qr must still preserve the labels for different dtypes
|
||||
# of the generic fixed input even if the labels may be meaningless.
|
||||
random_state = np.random.RandomState(seed=8)
|
||||
n_samples, n_components = 10, 5
|
||||
data = random_state.randn(n_samples, n_components)
|
||||
labels_float64 = cluster_qr(data.astype(np.float64))
|
||||
# Each sample is assigned a cluster identifier
|
||||
assert labels_float64.shape == (n_samples,)
|
||||
# All components should be covered by the assignment
|
||||
assert np.array_equal(np.unique(labels_float64), np.arange(n_components))
|
||||
# Single precision data should yield the same cluster assignments
|
||||
labels_float32 = cluster_qr(data.astype(np.float32))
|
||||
assert np.array_equal(labels_float64, labels_float32)
|
||||
|
||||
|
||||
def test_cluster_qr_permutation_invariance():
|
||||
# cluster_qr must be invariant to sample permutation.
|
||||
random_state = np.random.RandomState(seed=8)
|
||||
n_samples, n_components = 100, 5
|
||||
data = random_state.randn(n_samples, n_components)
|
||||
perm = random_state.permutation(n_samples)
|
||||
assert np.array_equal(
|
||||
cluster_qr(data)[perm],
|
||||
cluster_qr(data[perm]),
|
||||
)
|
||||
|
||||
|
||||
@pytest.mark.parametrize("n_samples", [50, 100, 150, 500])
|
||||
def test_discretize(n_samples):
|
||||
# Test the discretize using a noise assignment matrix
|
||||
random_state = np.random.RandomState(seed=8)
|
||||
for n_class in range(2, 10):
|
||||
# random class labels
|
||||
y_true = random_state.randint(0, n_class + 1, n_samples)
|
||||
y_true = np.array(y_true, float)
|
||||
# noise class assignment matrix
|
||||
y_indicator = sparse.coo_matrix(
|
||||
(np.ones(n_samples), (np.arange(n_samples), y_true)),
|
||||
shape=(n_samples, n_class + 1),
|
||||
)
|
||||
y_true_noisy = y_indicator.toarray() + 0.1 * random_state.randn(
|
||||
n_samples, n_class + 1
|
||||
)
|
||||
y_pred = discretize(y_true_noisy, random_state=random_state)
|
||||
assert adjusted_rand_score(y_true, y_pred) > 0.8
|
||||
|
||||
|
||||
# TODO: Remove when pyamg does replaces sp.rand call with np.random.rand
|
||||
# https://github.com/scikit-learn/scikit-learn/issues/15913
|
||||
@pytest.mark.filterwarnings(
|
||||
"ignore:scipy.rand is deprecated:DeprecationWarning:pyamg.*"
|
||||
)
|
||||
# TODO: Remove when pyamg removes the use of np.float
|
||||
@pytest.mark.filterwarnings(
|
||||
"ignore:`np.float` is a deprecated alias:DeprecationWarning:pyamg.*"
|
||||
)
|
||||
# TODO: Remove when pyamg removes the use of pinv2
|
||||
@pytest.mark.filterwarnings(
|
||||
"ignore:scipy.linalg.pinv2 is deprecated:DeprecationWarning:pyamg.*"
|
||||
)
|
||||
def test_spectral_clustering_with_arpack_amg_solvers():
|
||||
# Test that spectral_clustering is the same for arpack and amg solver
|
||||
# Based on toy example from plot_segmentation_toy.py
|
||||
|
||||
# a small two coin image
|
||||
x, y = np.indices((40, 40))
|
||||
|
||||
center1, center2 = (14, 12), (20, 25)
|
||||
radius1, radius2 = 8, 7
|
||||
|
||||
circle1 = (x - center1[0]) ** 2 + (y - center1[1]) ** 2 < radius1**2
|
||||
circle2 = (x - center2[0]) ** 2 + (y - center2[1]) ** 2 < radius2**2
|
||||
|
||||
circles = circle1 | circle2
|
||||
mask = circles.copy()
|
||||
img = circles.astype(float)
|
||||
|
||||
graph = img_to_graph(img, mask=mask)
|
||||
graph.data = np.exp(-graph.data / graph.data.std())
|
||||
|
||||
labels_arpack = spectral_clustering(
|
||||
graph, n_clusters=2, eigen_solver="arpack", random_state=0
|
||||
)
|
||||
|
||||
assert len(np.unique(labels_arpack)) == 2
|
||||
|
||||
if amg_loaded:
|
||||
labels_amg = spectral_clustering(
|
||||
graph, n_clusters=2, eigen_solver="amg", random_state=0
|
||||
)
|
||||
assert adjusted_rand_score(labels_arpack, labels_amg) == 1
|
||||
else:
|
||||
with pytest.raises(ValueError):
|
||||
spectral_clustering(graph, n_clusters=2, eigen_solver="amg", random_state=0)
|
||||
|
||||
|
||||
def test_n_components():
|
||||
# Test that after adding n_components, result is different and
|
||||
# n_components = n_clusters by default
|
||||
X, y = make_blobs(
|
||||
n_samples=20, random_state=0, centers=[[1, 1], [-1, -1]], cluster_std=0.01
|
||||
)
|
||||
sp = SpectralClustering(n_clusters=2, random_state=0)
|
||||
labels = sp.fit(X).labels_
|
||||
# set n_components = n_cluster and test if result is the same
|
||||
labels_same_ncomp = (
|
||||
SpectralClustering(n_clusters=2, n_components=2, random_state=0).fit(X).labels_
|
||||
)
|
||||
# test that n_components=n_clusters by default
|
||||
assert_array_equal(labels, labels_same_ncomp)
|
||||
|
||||
# test that n_components affect result
|
||||
# n_clusters=8 by default, and set n_components=2
|
||||
labels_diff_ncomp = (
|
||||
SpectralClustering(n_components=2, random_state=0).fit(X).labels_
|
||||
)
|
||||
assert not np.array_equal(labels, labels_diff_ncomp)
|
||||
|
||||
|
||||
@pytest.mark.parametrize("assign_labels", ("kmeans", "discretize", "cluster_qr"))
|
||||
def test_verbose(assign_labels, capsys):
|
||||
# Check verbose mode of KMeans for better coverage.
|
||||
X, y = make_blobs(
|
||||
n_samples=20, random_state=0, centers=[[1, 1], [-1, -1]], cluster_std=0.01
|
||||
)
|
||||
|
||||
SpectralClustering(n_clusters=2, random_state=42, verbose=1).fit(X)
|
||||
|
||||
captured = capsys.readouterr()
|
||||
|
||||
assert re.search(r"Computing label assignment using", captured.out)
|
||||
|
||||
if assign_labels == "kmeans":
|
||||
assert re.search(r"Initialization complete", captured.out)
|
||||
assert re.search(r"Iteration [0-9]+, inertia", captured.out)
|
||||
|
||||
|
||||
def test_spectral_clustering_np_matrix_raises():
|
||||
"""Check that spectral_clustering raises an informative error when passed
|
||||
a np.matrix. See #10993"""
|
||||
X = np.matrix([[0.0, 2.0], [2.0, 0.0]])
|
||||
|
||||
msg = r"spectral_clustering does not support passing in affinity as an np\.matrix"
|
||||
with pytest.raises(TypeError, match=msg):
|
||||
spectral_clustering(X)
|
||||
|
||||
|
||||
def test_spectral_clustering_not_infinite_loop(capsys, monkeypatch):
|
||||
"""Check that discretize raises LinAlgError when svd never converges.
|
||||
|
||||
Non-regression test for #21380
|
||||
"""
|
||||
|
||||
def new_svd(*args, **kwargs):
|
||||
raise LinAlgError()
|
||||
|
||||
monkeypatch.setattr(np.linalg, "svd", new_svd)
|
||||
vectors = np.ones((10, 4))
|
||||
|
||||
with pytest.raises(LinAlgError, match="SVD did not converge"):
|
||||
discretize(vectors)
|
||||
Reference in New Issue
Block a user