sklearn.decomposition.MiniBatchSparsePCA¶

class sklearn.decomposition.MiniBatchSparsePCA(n_components=None, *, alpha=1, ridge_alpha=0.01, n_iter='deprecated', max_iter=None, callback=None, batch_size=3, verbose=False, shuffle=True, n_jobs=None, method='lars', random_state=None, tol=0.001, max_no_improvement=10)[source]

Mini-batch Sparse Principal Components Analysis.

Finds the set of sparse components that can optimally reconstruct the data. The amount of sparseness is controllable by the coefficient of the L1 penalty, given by the parameter alpha.

Read more in the User Guide.

Parameters:
n_componentsint, default=None

Number of sparse atoms to extract. If None, then n_components is set to n_features.

alphaint, default=1

Sparsity controlling parameter. Higher values lead to sparser components.

ridge_alphafloat, default=0.01

Amount of ridge shrinkage to apply in order to improve conditioning when calling the transform method.

n_iterint, default=100

Number of iterations to perform for each mini batch.

Deprecated since version 1.2: n_iter is deprecated in 1.2 and will be removed in 1.4. Use max_iter instead.

max_iterint, default=None

Maximum number of iterations over the complete dataset before stopping independently of any early stopping criterion heuristics. If max_iter is not None, n_iter is ignored.

New in version 1.2.

callbackcallable, default=None

Callable that gets invoked every five iterations.

batch_sizeint, default=3

The number of features to take in each mini batch.

verboseint or bool, default=False

Controls the verbosity; the higher, the more messages. Defaults to 0.

shufflebool, default=True

Whether to shuffle the data before splitting it in batches.

n_jobsint, default=None

Number of parallel jobs to run. None means 1 unless in a joblib.parallel_backend context. -1 means using all processors. See Glossary for more details.

method{‘lars’, ‘cd’}, default=’lars’

Method to be used for optimization. lars: uses the least angle regression method to solve the lasso problem (linear_model.lars_path) cd: uses the coordinate descent method to compute the Lasso solution (linear_model.Lasso). Lars will be faster if the estimated components are sparse.

random_stateint, RandomState instance or None, default=None

Used for random shuffling when shuffle is set to True, during online dictionary learning. Pass an int for reproducible results across multiple function calls. See Glossary.

tolfloat, default=1e-3

Control early stopping based on the norm of the differences in the dictionary between 2 steps. Used only if max_iter is not None.

To disable early stopping based on changes in the dictionary, set tol to 0.0.

New in version 1.1.

max_no_improvementint or None, default=10

Control early stopping based on the consecutive number of mini batches that does not yield an improvement on the smoothed cost function. Used only if max_iter is not None.

To disable convergence detection based on cost function, set max_no_improvement to None.

New in version 1.1.

Attributes:
components_ndarray of shape (n_components, n_features)

Sparse components extracted from the data.

n_components_int

Estimated number of components.

New in version 0.23.

n_iter_int

Number of iterations run.

mean_ndarray of shape (n_features,)

Per-feature empirical mean, estimated from the training set. Equal to X.mean(axis=0).

n_features_in_int

Number of features seen during fit.

New in version 0.24.

feature_names_in_ndarray of shape (n_features_in_,)

Names of features seen during fit. Defined only when X has feature names that are all strings.

New in version 1.0.

See also

DictionaryLearning

Find a dictionary that sparsely encodes data.

IncrementalPCA

Incremental principal components analysis.

PCA

Principal component analysis.

SparsePCA

Sparse Principal Components Analysis.

TruncatedSVD

Dimensionality reduction using truncated SVD.

Examples

>>> import numpy as np
>>> from sklearn.datasets import make_friedman1
>>> from sklearn.decomposition import MiniBatchSparsePCA
>>> X, _ = make_friedman1(n_samples=200, n_features=30, random_state=0)
>>> transformer = MiniBatchSparsePCA(n_components=5, batch_size=50,
...                                  max_iter=10, random_state=0)
>>> transformer.fit(X)
MiniBatchSparsePCA(...)
>>> X_transformed = transformer.transform(X)
>>> X_transformed.shape
(200, 5)
>>> # most values in the components_ are zero (sparsity)
>>> np.mean(transformer.components_ == 0)
0.9...


Methods

 fit(X[, y]) Fit the model from data in X. fit_transform(X[, y]) Fit to data, then transform it. get_feature_names_out([input_features]) Get output feature names for transformation. get_params([deep]) Get parameters for this estimator. Transform data from the latent space to the original space. set_params(**params) Set the parameters of this estimator. Least Squares projection of the data onto the sparse components.
fit(X, y=None)[source]

Fit the model from data in X.

Parameters:
Xarray-like of shape (n_samples, n_features)

Training vector, where n_samples is the number of samples and n_features is the number of features.

yIgnored

Not used, present here for API consistency by convention.

Returns:
selfobject

Returns the instance itself.

fit_transform(X, y=None, **fit_params)[source]

Fit to data, then transform it.

Fits transformer to X and y with optional parameters fit_params and returns a transformed version of X.

Parameters:
Xarray-like of shape (n_samples, n_features)

Input samples.

yarray-like of shape (n_samples,) or (n_samples, n_outputs), default=None

Target values (None for unsupervised transformations).

**fit_paramsdict

Additional fit parameters.

Returns:
X_newndarray array of shape (n_samples, n_features_new)

Transformed array.

get_feature_names_out(input_features=None)[source]

Get output feature names for transformation.

Parameters:
input_featuresarray-like of str or None, default=None

Only used to validate feature names with the names seen in fit.

Returns:
feature_names_outndarray of str objects

Transformed feature names.

get_params(deep=True)[source]

Get parameters for this estimator.

Parameters:
deepbool, default=True

If True, will return the parameters for this estimator and contained subobjects that are estimators.

Returns:
paramsdict

Parameter names mapped to their values.

inverse_transform(X)[source]

Transform data from the latent space to the original space.

This inversion is an approximation due to the loss of information induced by the forward decomposition.

New in version 1.2.

Parameters:
Xndarray of shape (n_samples, n_components)

Data in the latent space.

Returns:
X_originalndarray of shape (n_samples, n_features)

Reconstructed data in the original space.

set_params(**params)[source]

Set the parameters of this estimator.

The method works on simple estimators as well as on nested objects (such as Pipeline). The latter have parameters of the form <component>__<parameter> so that it’s possible to update each component of a nested object.

Parameters:
**paramsdict

Estimator parameters.

Returns:
selfestimator instance

Estimator instance.

transform(X)[source]

Least Squares projection of the data onto the sparse components.

To avoid instability issues in case the system is under-determined, regularization can be applied (Ridge regression) via the ridge_alpha parameter.

Note that Sparse PCA components orthogonality is not enforced as in PCA hence one cannot use a simple linear projection.

Parameters:
Xndarray of shape (n_samples, n_features)

Test data to be transformed, must have the same number of features as the data used to train the model.

Returns:
X_newndarray of shape (n_samples, n_components)

Transformed data.

Examples using sklearn.decomposition.MiniBatchSparsePCA¶

Faces dataset decompositions

Faces dataset decompositions