class sklearn.cluster.MiniBatchKMeans(n_clusters=8, init=’k-means++’, max_iter=100, batch_size=100, verbose=0, compute_labels=True, random_state=None, tol=0.0, max_no_improvement=10, init_size=None, n_init=3, reassignment_ratio=0.01)
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Mini-Batch K-Means clustering
Read more in the User Guide.
Parameters: |
n_clusters : int, optional, default: 8 The number of clusters to form as well as the number of centroids to generate. init : {‘k-means++’, ‘random’ or an ndarray}, default: ‘k-means++’ Method for initialization, defaults to ‘k-means++’: ‘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 k observations (rows) at random from data for the initial centroids. If an ndarray is passed, it should be of shape (n_clusters, n_features) and gives the initial centers. max_iter : int, optional Maximum number of iterations over the complete dataset before stopping independently of any early stopping criterion heuristics. batch_size : int, optional, default: 100 Size of the mini batches. verbose : boolean, optional Verbosity mode. compute_labels : boolean, default=True Compute label assignment and inertia for the complete dataset once the minibatch optimization has converged in fit. random_state : int, RandomState instance or None, optional, default: None If int, random_state is the seed used by the random number generator; If RandomState instance, random_state is the random number generator; If None, the random number generator is the RandomState instance used by tol : float, default: 0.0 Control early stopping based on the relative center changes as measured by a smoothed, variance-normalized of the mean center squared position changes. This early stopping heuristics is closer to the one used for the batch variant of the algorithms but induces a slight computational and memory overhead over the inertia heuristic. To disable convergence detection based on normalized center change, set tol to 0.0 (default). max_no_improvement : int, default: 10 Control early stopping based on the consecutive number of mini batches that does not yield an improvement on the smoothed inertia. To disable convergence detection based on inertia, set max_no_improvement to None. init_size : int, optional, default: 3 * batch_size Number of samples to randomly sample for speeding up the initialization (sometimes at the expense of accuracy): the only algorithm is initialized by running a batch KMeans on a random subset of the data. This needs to be larger than n_clusters. n_init : int, default=3 Number of random initializations that are tried. In contrast to KMeans, the algorithm is only run once, using the best of the reassignment_ratio : float, default: 0.01 Control the fraction of the maximum number of counts for a center to be reassigned. A higher value means that low count centers are more easily reassigned, which means that the model will take longer to converge, but should converge in a better clustering. |
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Attributes: |
cluster_centers_ : array, [n_clusters, n_features] Coordinates of cluster centers labels_ : : Labels of each point (if compute_labels is set to True). inertia_ : float The value of the inertia criterion associated with the chosen partition (if compute_labels is set to True). The inertia is defined as the sum of square distances of samples to their nearest neighbor. |
See also
KMeans
See http://www.eecs.tufts.edu/~dsculley/papers/fastkmeans.pdf
fit (X[, y]) | Compute the centroids on X by chunking it into mini-batches. |
fit_predict (X[, y]) | Compute cluster centers and predict cluster index for each sample. |
fit_transform (X[, y]) | Compute clustering and transform X to cluster-distance space. |
get_params ([deep]) | Get parameters for this estimator. |
partial_fit (X[, y]) | Update k means estimate on a single mini-batch X. |
predict (X) | Predict the closest cluster each sample in X belongs to. |
score (X[, y]) | Opposite of the value of X on the K-means objective. |
set_params (**params) | Set the parameters of this estimator. |
transform (X) | Transform X to a cluster-distance space. |
__init__(n_clusters=8, init=’k-means++’, max_iter=100, batch_size=100, verbose=0, compute_labels=True, random_state=None, tol=0.0, max_no_improvement=10, init_size=None, n_init=3, reassignment_ratio=0.01)
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fit(X, y=None)
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Compute the centroids on X by chunking it into mini-batches.
Parameters: |
X : array-like or sparse matrix, shape=(n_samples, n_features) Training instances to cluster. y : Ignored |
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fit_predict(X, y=None)
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Compute cluster centers and predict cluster index for each sample.
Convenience method; equivalent to calling fit(X) followed by predict(X).
Parameters: |
X : {array-like, sparse matrix}, shape = [n_samples, n_features] New data to transform. u : Ignored |
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Returns: |
labels : array, shape [n_samples,] Index of the cluster each sample belongs to. |
fit_transform(X, y=None)
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Compute clustering and transform X to cluster-distance space.
Equivalent to fit(X).transform(X), but more efficiently implemented.
Parameters: |
X : {array-like, sparse matrix}, shape = [n_samples, n_features] New data to transform. y : Ignored |
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Returns: |
X_new : array, shape [n_samples, k] X transformed in the new space. |
get_params(deep=True)
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Get parameters for this estimator.
Parameters: |
deep : boolean, optional If True, will return the parameters for this estimator and contained subobjects that are estimators. |
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Returns: |
params : mapping of string to any Parameter names mapped to their values. |
partial_fit(X, y=None)
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Update k means estimate on a single mini-batch X.
Parameters: |
X : array-like, shape = [n_samples, n_features] Coordinates of the data points to cluster. y : Ignored |
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predict(X)
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Predict the closest cluster each sample in X belongs to.
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}, shape = [n_samples, n_features] New data to predict. |
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Returns: |
labels : array, shape [n_samples,] Index of the cluster each sample belongs to. |
score(X, y=None)
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Opposite of the value of X on the K-means objective.
Parameters: |
X : {array-like, sparse matrix}, shape = [n_samples, n_features] New data. y : Ignored |
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Returns: |
score : float Opposite of the value of X on the K-means objective. |
set_params(**params)
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Set the parameters of this estimator.
The method works on simple estimators as well as on nested objects (such as pipelines). The latter have parameters of the form <component>__<parameter>
so that it’s possible to update each component of a nested object.
Returns: | self : |
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transform(X)
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Transform X to a cluster-distance space.
In the new space, each dimension is the distance to the cluster centers. Note that even if X is sparse, the array returned by transform
will typically be dense.
Parameters: |
X : {array-like, sparse matrix}, shape = [n_samples, n_features] New data to transform. |
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Returns: |
X_new : array, shape [n_samples, k] X transformed in the new space. |
sklearn.cluster.MiniBatchKMeans
© 2007–2017 The scikit-learn developers
Licensed under the 3-clause BSD License.
http://scikit-learn.org/stable/modules/generated/sklearn.cluster.MiniBatchKMeans.html