SklearnClassifier#

class skactiveml.classifier.SklearnClassifier(estimator, include_unlabeled_samples=False, classes=None, missing_label=nan, cost_matrix=None, random_state=None)[source]#

Bases: SkactivemlClassifier, MetaEstimatorMixin

Sklearn Classifier

Implementation of a wrapper class for scikit-learn classifiers such that missing labels can be handled. Therefore, samples with missing labels are filtered.

Parameters:
estimatorsklearn.base.ClassifierMixin with predict_proba method

The scikit-learn classifier to be wrapped.

include_unlabeled_samplesbool, default=False
  • If False, only labeled samples are passed to the fit method of the estimator.

  • If True, all samples including the unlabeled ones are passed to the fit method of the estimator. Ensure that your estimator is able to handle unlabeled samples marked by missing_label. Otherwise, missing_label is interpreted as a regular class label. Note that semi-supervised classifiers of sklearn expect missing_label=-1.

classesarray-like of shape (n_classes,), default=None

Holds the label for each class. If None, the classes are determined during fit.

missing_labelscalar or string or np.nan or None, default=np.nan

Value to represent a missing label.

cost_matrixarray-like of shape (n_classes, n_classes)

Cost matrix with cost_matrix[i,j] indicating cost of predicting class classes[j] for a sample of class classes[i]. Can be only set, if classes is not None.

random_stateint or RandomState instance or None, default=None

Determines random number for predict method. Pass an int for reproducible results across multiple method calls.

Attributes:
classes_numpy.ndarray of shape (n_classes,)

Holds the label for each class after fitting.

cost_matrix_numpy.ndarray of shape (classes, classes)

Cost matrix with cost_matrix_[i,j] indicating cost of predicting class classes_[j] for a sample of class classes_[i].

estimator_sklearn.base.ClassifierMixin with predict_proba method

The scikit-learn classifier after calling the fit method.

Methods

fit(X, y[, sample_weight])

Fit the model using X as training data and y as class labels.

get_metadata_routing()

Get metadata routing of this object.

get_params([deep])

Get parameters for this estimator.

partial_fit(X, y[, sample_weight])

Partially fitting the model using X as training data and y as class labels.

predict(X, **predict_kwargs)

Return class label predictions for the input data X.

predict_proba(X, **predict_proba_kwargs)

Return probability estimates for the input data X.

score(X, y[, sample_weight])

Return the mean accuracy on the given test data and labels.

set_fit_request(*[, sample_weight])

Configure whether metadata should be requested to be passed to the fit method.

set_params(**params)

Set the parameters of this estimator.

set_partial_fit_request(*[, sample_weight])

Configure whether metadata should be requested to be passed to the partial_fit method.

set_score_request(*[, sample_weight])

Configure whether metadata should be requested to be passed to the score method.

fit(X, y, sample_weight=None, **fit_kwargs)[source]#

Fit the model using X as training data and y as class labels.

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

The feature matrix representing the samples.

yarray-like of shape (n_samples,) or (n_samples, n_outputs)

It contains the class labels of the training samples. Missing labels are represented the attribute self.missing_label_. In case of multiple labels per sample (i.e., n_outputs > 1), the samples are duplicated.

sample_weightarray-like of shape (n_samples,) or (n_samples, n_outputs)

It contains the weights of the training samples’ class labels. It must have the same shape as y.

fit_kwargsdict-like

Further parameters as input to the fit method of the estimator.

Returns:
self: SklearnClassifier,

The SklearnClassifier fitted on the training data.

get_metadata_routing()#

Get metadata routing of this object.

Please check User Guide on how the routing mechanism works.

Returns:
routingMetadataRequest

A MetadataRequest encapsulating routing information.

get_params(deep=True)#

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.

partial_fit(X, y, sample_weight=None, **fit_kwargs)[source]#

Partially fitting the model using X as training data and y as class labels.

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

The feature matrix representing the samples.

yarray-like of shape (n_samples,) or (n_samples, n_outputs)

It contains the class labels of the training samples. Missing labels are represented the attribute self.missing_label_. In case of multiple labels per sample (i.e., n_outputs > 1), the samples are duplicated.

sample_weightarray-like of shape (n_samples,) or (n_samples, n_outputs)

It contains the weights of the training samples’ class labels. It must have the same shape as y.

fit_kwargsdict-like

Further parameters as input to the partial_fit method of the estimator.

Returns:
selfSklearnClassifier,

The SklearnClassifier is fitted on the training data.

predict(X, **predict_kwargs)[source]#

Return class label predictions for the input data X.

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

Input samples.

predict_kwargsdict-like

Further parameters as input to the predict method of the estimator.

Returns:
y_prednumpy.ndarray of shape (n_samples,)

Predicted class labels of the input samples.

predict_proba(X, **predict_proba_kwargs)[source]#

Return probability estimates for the input data X.

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

Input samples.

predict_proba_kwargsdict-like

Further parameters as input to the predict_proba method of the estimator.

Returns:
Parray-like of shape (n_samples, classes)

The class probabilities of the input samples. Classes are ordered according to the attribute self.classes_.

score(X, y, sample_weight=None)#

Return the mean accuracy on the given test data and labels.

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

Test samples.

yarray-like of shape (n_samples,)

True labels for X.

sample_weightarray-like of shape (n_samples,), default=None

Sample weights.

Returns:
scorefloat

Mean accuracy of self.predict(X) regarding y.

set_fit_request(*, sample_weight: bool | None | str = '$UNCHANGED$') SklearnClassifier#

Configure whether metadata should be requested to be passed to the fit method.

Note that this method is only relevant when this estimator is used as a sub-estimator within a meta-estimator and metadata routing is enabled with enable_metadata_routing=True (see sklearn.set_config()). Please check the User Guide on how the routing mechanism works.

The options for each parameter are:

  • True: metadata is requested, and passed to fit if provided. The request is ignored if metadata is not provided.

  • False: metadata is not requested and the meta-estimator will not pass it to fit.

  • None: metadata is not requested, and the meta-estimator will raise an error if the user provides it.

  • str: metadata should be passed to the meta-estimator with this given alias instead of the original name.

The default (sklearn.utils.metadata_routing.UNCHANGED) retains the existing request. This allows you to change the request for some parameters and not others.

Added in version 1.3.

Parameters:
sample_weightstr, True, False, or None, default=sklearn.utils.metadata_routing.UNCHANGED

Metadata routing for sample_weight parameter in fit.

Returns:
selfobject

The updated object.

set_params(**params)#

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.

set_partial_fit_request(*, sample_weight: bool | None | str = '$UNCHANGED$') SklearnClassifier#

Configure whether metadata should be requested to be passed to the partial_fit method.

Note that this method is only relevant when this estimator is used as a sub-estimator within a meta-estimator and metadata routing is enabled with enable_metadata_routing=True (see sklearn.set_config()). Please check the User Guide on how the routing mechanism works.

The options for each parameter are:

  • True: metadata is requested, and passed to partial_fit if provided. The request is ignored if metadata is not provided.

  • False: metadata is not requested and the meta-estimator will not pass it to partial_fit.

  • None: metadata is not requested, and the meta-estimator will raise an error if the user provides it.

  • str: metadata should be passed to the meta-estimator with this given alias instead of the original name.

The default (sklearn.utils.metadata_routing.UNCHANGED) retains the existing request. This allows you to change the request for some parameters and not others.

Added in version 1.3.

Parameters:
sample_weightstr, True, False, or None, default=sklearn.utils.metadata_routing.UNCHANGED

Metadata routing for sample_weight parameter in partial_fit.

Returns:
selfobject

The updated object.

set_score_request(*, sample_weight: bool | None | str = '$UNCHANGED$') SklearnClassifier#

Configure whether metadata should be requested to be passed to the score method.

Note that this method is only relevant when this estimator is used as a sub-estimator within a meta-estimator and metadata routing is enabled with enable_metadata_routing=True (see sklearn.set_config()). Please check the User Guide on how the routing mechanism works.

The options for each parameter are:

  • True: metadata is requested, and passed to score if provided. The request is ignored if metadata is not provided.

  • False: metadata is not requested and the meta-estimator will not pass it to score.

  • None: metadata is not requested, and the meta-estimator will raise an error if the user provides it.

  • str: metadata should be passed to the meta-estimator with this given alias instead of the original name.

The default (sklearn.utils.metadata_routing.UNCHANGED) retains the existing request. This allows you to change the request for some parameters and not others.

Added in version 1.3.

Parameters:
sample_weightstr, True, False, or None, default=sklearn.utils.metadata_routing.UNCHANGED

Metadata routing for sample_weight parameter in score.

Returns:
selfobject

The updated object.

Examples using skactiveml.classifier.SklearnClassifier#

Batch Bayesian Active Learning by Disagreement (BatchBALD)

Batch Bayesian Active Learning by Disagreement (BatchBALD)

Bayesian Active Learning by Disagreement (BALD)

Bayesian Active Learning by Disagreement (BALD)

Density-weighted Uncertainty Sampling (DWUS)

Density-weighted Uncertainty Sampling (DWUS)

Dual Strategy for Active Learning

Dual Strategy for Active Learning